Nbde Bio Physio

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1A deficiency of choline in the diet may cause abnormalities in metabolism of

1. lipids.

2. proteins.

3. minerals.

4. carbohydrates.

5. nucleoproteins.

The correct answer is choice 1. Choline is a structural component of phosphatidylcholine or

lecithin, a phosphoglyceride. Phosphoglycerides are maor components of cell membranes. The

raw material for the synthesis of phosphatidylcholine is dietary choline. !n the absence ofcholine, phosphatidylcholine cannot be produced and a maor phospholipid component of wall

membranes will be una"ailable. #o the correct answer to $uestion is choice 1. Choline is notdirectly in"ol"ed in the metabolism of the other choices% proteins, minerals, carbohydrates or

nucleoproteins.

2. A deficiency of rhodopsin is most likely caused by decreased dietary intake of

1. glucose.

2. adenine.

3. "itamin &.

4. tryptophan.

5. ribofla"in.

The correct choice to $uestion is '3, "itamin &. (hodopsin is a photosensiti"e molecule in rods.

!t is made up of opsin and 1)cis)retinal. The precursor of 11)cis)retinal is !!)trans)retinol, or"itamin &. *itamin & is an essential "itamin+ that is, it cannot be synthesied in mammals. The

all)trans)retinol is con"erted to 11)cis)retinal by retinol dehydrogenase, followed by anisomeriation between the 11th and 12th carbon double bonds, from trans to cis configuration

by retinal isomerase. !f "itamin & is deficient in the human it will lead to night blindness ande"entual degeneration of the rods. #o the correct choice is '3, "itamin &.

3 A deficiency of vitamin A in a developing tooth most likely affects the

1. pulp.

2. enamel.

3. dentin.

4. cementum

&ns 2 ...-nly *it & &nd C are in"ol"ed in tooth enal n dentin de"elopment.... now *it C is

in"ol"ed with collagen synthesis n dentin has more collagen compared to enamel so *it C help in

dentin de"elopment n *it & with namel de"elopment

The correct answer is '2. To answer this $uestion it is important to thin/ bac/ to thede"elopment of the tooth. !n loo/ing at our choices, pulp enamel, dentine and cementum, we

see that dentine, cementum and pulp are classified as connecti"e tissues, while enamel may beclassified as a product of epithelial cells. The tooth, therefore, is from mesenchymal andectodermal origin. The mesenchyme is deri"ed from neural crest, and the epithelium, as !

mentioned before, is deri"ed from ectoderm. *itamin & plays a /ey role in protein synthesis of

epithelial cells. The e0act role has not been elucidated. owe"er, you can see here that you cananswer this $uestion by ust loo/ing at your choices. #o again, the correct choice is '2.


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4 A derivative of vitamin K is the coenzyme for which of the following?

&. Production of menadiol

. steilfication of retinol

C. ydrolysis of peptide bonds

. Cross)lin/ing of fibrinogen

. Carbo0ylation of glutamate side chains

The correct answer is Choice . *itamin is essential for the normal synthesis of prothrombrin

and se"eral other clotting factors in the li"er. !t acts as a coenyme for the carbo0ylation of

glutamate side chains Choice 6 into 7 ) carbo0yglutamate. 8ithout this "itamin )independent

carbo0ylation reaction, the prothrombin formed does not bind ca29 and may result in

hemorrhage and death. Choice & through are incorrect as "itamin is not the coenyme for

any of the reactions listed.

A disease that results in the destruction of a large number of cells and their

nuclei would be e!pected to cause an increased blood level of which of the

following?

&. &mmonia

. :&

C. etones

. ;itochondria

.


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#he correct answer is $.#ince bones are adaptable, their shapes often reflect the forces applied to them on a regular

basis. @or e0ample, the "arious bumps and ridges on the surface of bone often indicate the siteswhere tendons attach to the bone. &s the muscle becomes stronger and the force applied to the

bone becomes larger, these bumps and ridges will become larger to withstand the increasedforce applied to them. Con"ersely, during periods of inacti"ity the sie of the bone will decrease

and the bone will subse$uently become thin and brittle. !n general, bones are able to store

more calcium choice &6, increase in length choice C6, and the thic/ness of the bone willincrease in periods of acti"ity choice 6. ased on this information, it is easy to conclude thate0ercise or lac/ thereof does ha"e an effect on bone choice 6.

=.

A man is being chased by a vicious dog. %econdary to stimulation of the

sympathetic nervous system& which of the following would most likely occur?

&. ecreased heart rate

. ilation of the peripheral blood "essels

C. ilation of the pupils

. !ncreased peristalsis in the small intestine

. lncreased secretions of the sali"ary glands

#he correct answer is '.

The sympathetic ner"ous system promotes the Afight or flightA reaction. uring periods ofstress, the sympathetic ner"ous system will help the body handle the stressor by promoting a

series of physiologic changes. @or e0ample, one would e0pect to see dilation of the pupils,secretion of the sweat glands, increased heart rate, constriction of the blood "essels to

nonessential organs, bronchodilation, and decreased peristalsis. &ll the other answer choicedecreased heart rate choice &6, dilation of the peripheral blood "essels choice 6, increased

peristalsis in the small intestine choice 6, and increased secretions of the sali"ary glandschoice 6 would be e0pected to occur with the stimulation of the parasympathetic ner"oussystem.

B A muscle devoid oftonus is

1. atonic.

2. spastic.

3. hypotonic.

4. hypertonic.

The correct choice is '1, atonic. This is a simple definition)type problem.

&n atonic muscle will be flaccid. The muscle will be freely mo"able, and lies without

tone. This occurs with lower motor neuron lesions+ that is, the destruction of the alpha

motor neurons.

#pasticity is a hypertonus state of the affected muscles. This is due to a release of the

tonic inhibition of the brainstem, facilitory information which leads to gamma motor

neuron e0citation.

Thus, hyperacti"ity of the gamma fibers causes e0aggerated response to stretch of

muscle spindles. ypotonia is simply a decrease in alpha motor neuron stimulation+

howe"er, not a complete destruction. #o therefore we ha"e partial tone loss. #o again,

the correct choice to $uestion is '1, atonic.

1


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A patient diagnosed with cystinuria will have difficulties reabsorbing all of the

following in the renal tubules ()'(*#

&. arginine

. cysteine

C. lysine

. methionine

. ornithine

The correct answer is .The transport systems for amino acids in the intestinal and luminal cells are similar to those for

glucose, where transport across the luminal membrane is sodium dependent and transportacross the contraluminal membrane is sodium independent. Denetic deficiencies in a "ariety of

these carrier systems ha"e been identified. @or e0ample, cystinuria is a clinical condition arisingfrom faulty transport mechanisms. !t is an autosomal)recessi"e disease caused by a defect in

the transport of cysteine, ornithine, arginine, and lysine, resulting in these amino acids beinge0creted in the urine. & mnemonic% cystinuria results from an inability to reabsorb C-&?

cysteine, ornithine, arginine, and lysine6 in the renal tubules.

11.

A patient presents with dry skin& cold intolerance& constipation& muscle

weakness& recent weight gain& chronic lethargy& easy fatigue& loss of ambition&

and periorbital puffiness. #his patient+s condition is most likely caused by which

of the following?

&. &ldosterone hypersecretion

. &ndrogen hypersecretion

C. ypercortisolism

. ypocorticoidism

. ypothyroidism

The correct answer is .

ypothyroidism, or my0edema, is caused by a lac/ of thyroid function. Patients with this

condition often present with dry s/in, cold intolerance, constipation, muscle wea/ness, recent

weight gain, chronic lethargy, easy fatigue, loss of ambition, and periorbital puffiness.

&ldosteronism is caused by a hypersecretion of aldosterone choice &6, leading to hypo/alemia,which can e"entually lead to periods of muscle paralysis. &drenogenital syndrome is the result

of e0cessi"e production of androgens choice 6, leading to premature masculiniing effects in

young males. Cushing syndrome, which is caused by a hypersecretion of cortisol choice C6 by

the adrenal corte0, is characteried by an increased fat deposition in the thoracic region and an

edematous appearance of the face+ it may also cause acne and hirsutism. &ddison disease

results from the failure of the adrenal corte0 to produce adrenocortical hormones, resulting in

glucocorticoid choice 6 and mineralocorticoid deficiency. ?oss of cortisol a glucocorticoid6

secretion results in the depression of many metabolic functions and decreases oneEs ability to

tolerate "arious stressors.


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A person who is severely deficient in folic acid would most likely e!perience

which of the following?

&. &cidosis

. &nemia

C. emorrhage

. #eiure

. Thrombocytopenia

The correct answer is . &nemia is a condition mar/ed by a reduction in the hemoglobin and>or

hematocrit content of the blood+ this condition can be caused by a number of factors, one ofwhich includes folic acid deficiency. @olic acid is the generic term for pteroylmonoglutamic acid,

which ser"es as an important mediator of many reactions in"ol"ing one)carbon transfers. Thissubstance is found in many fruits and "egetables, especially citrus fruits and green leafy

"egetables. The most common cause of folate deficiency is inade$uate dietary inta/e andindi"iduals most commonly seen with folate deficiency are alcoholics, the elderly and anore0ic

patients. The most common signs and symptoms of folic acid deficiency are megaloblasticanemia, with changes in the mucosa. The diagnosis is made upon finding macrocytic anemiawith macroo"alocytes and hypersegmented neutrophils on peripheral blood smear. &cidosischoice &6 is a condition where the blood p is less than =.4 and is not related to folic acid

content in the body. emorrhage choice C6 can be caused by a number of factors, including"itamin deficiency. &de$uate amounts of "itamin must be present for the li"er to be able to

synthesie four clotting factors, which include prothrombin. 8ithout "itamin , the entireclotting system will be inacti"ated. Therefore, if an indi"idual were "itamin deficient, they

would most li/ely e0perience some degree of hemorrhage because the body would be unable tostop bleeding in a traumatic e"ent. & seiure choice 6 can be defined as a condition

characteried by a sudden onset of con"ulsions or other epileptic symptoms+ its incidence is notincreased in folic acid deficiency. Thrombocytopenia choice 6 is characteried by an abnormally

low platelet count+ its incidence is also not increased in folic acid deficiency.

*hysiology

A protein in solution is at its isoelectric point when the

&. p is the same as that of the blood.

. logarithm of the concentration is ero.

C. p allows for ma0imum solubility.

. p is such that no migration occurs during electrophoresis.

. p is produced by a 1%1 mi0ture of the protein solution with isotonic saline.

The correct answer is Choice . The isoelectric point is the p reached when there is no net

electric charge on a protein. !n other words, no migration of a protein in an electric field occurs

during electrophoresis Choice 6 Choices &, , C, and do not describe isoelectric point.

A reduction in the population of which of the following lymphocytes would impair

all aspects of an immune response?

&. cells

. Cytoto0ic T cells

C. elper T cells

. ;emory T cells

. #uppressor T cells
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#he correct answer is '.

#pecific immunity is pro"ided by the coordinated acti"ities of both the T cells and cells whenantigens in"ade the human body. T cells play a crucial role in the initiation, maintenance and

control of the immune response. elper T cells stimulate the responses of both the T cells and

cells. They are absolutely essential to the immune response since cells and other T cells must

be acti"ated by the helper T cells. 8ithout helper T cells, an immune response to a gi"enpathogen will not be elicited. The immunodeficiency caused by the &!# "irus occurs secondaryto a reduction of helper T cells. cells choice &6 are responsible for launching a chemical attac/

on antigens through the production of antibodies+ without cells an immu.ne response can stillbe elicited by T cells. Cytoto0ic T cells choice C6 are responsible for cell mediated immiinity+

these cells pro"ide a direct physical and chemical attac/ on antigens. ;emory T cells choice 6remain long after an antigen enters the body. These cells ensure that an immediate immune

response is elicited when the AsameA antigen enters the body again. The suppressor T cellschoice 6 inhibit both T cell and cell acti"ities+ they moderate the immune response.

Acidosis is most likely to occur in patients severely deficient in which of the

following hormones?

&. &ntidiuretic hormone

. Calcitonin

C. !nsulin

. Prolactin

. Thyro0ine

The correct answer is C. etoacidosis, a specific form of acidosis, is most commonly seen indiabetic patients deficient in insulin. 8hen an indi"idual is insulin deficient, the cells of the body

are unable to properly utilie the glucose in the blood. Therefore, the body brea/s down fattyacids in an effort to maintain normal physiological functions. 8hen these fatty acids are bro/en

down, large numbers of /etone bodies are formed and the blood p decreases, leading tosystemic acidosis. &ntidiuretic hormone choice &6 pre"ents e0cessi"e water loss. !n the

absence of the hormone dehydration can occur. Calcitonin choice 6 is primarily responsible forthe regulation of calcium ion concentrations in the blood. 8hen blood le"els calcium ions

become ele"ated, calcitonin is secreted to reduce calcium ion le"els to normal limit. eficienciesof calcitonin would result in the de"elopment of hypercalcemia. Prolactin choice 6 is

responsible for the production of mil/ in the mammary glands of women after pregnancy. !f thehormone were deficient in a AnewA mother, mil/ production would be substantially decreased.

The thyroid hormones, such as thyro0ine choice 6, are responsible for the ele"ation of o0ygen

consumption and the rate of energy consumption+ increased heart rate+ stimulation of acti"ity ofother endocrine tissue+ maintenance of sensiti"ity of respiratory centers as well as "arious otherfunctions. !ndi"iduals deficient in thyroid hormones are typically lethargic, unable to adust to

cold temperatures, ha"e dry s/in and some degree of hair loss, muscle wea/ness and slowed

refle0es.

A,- receptors in the nephron are located on the tubular membrane of which of

the following?

&. istal tubule

. Pro0imal tubule

C. &scending loop of enle

. escending loop of enle

The correct answer is Choice &. The nephron is the functional unit of the /idney. !t is organiedinto different components each with specialied functions. & receptors are located on the

distal tubule Choice &6 portion of the nephron. The distal tubule is responsible for the


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reabsorption if ions such as sodium, potassium, and chloride.


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&. Constriction of pupils

. !ncreased heart rate

C. !ncreased sweat secretion

. (eduction of blood flow to the s/in

. (elease of stored lipids from subcutaneous adipose tissue

The correct answer is &. The maor actions of the postganglionic sympathetic fibers are as

follows% dilation of the pupils :-T constriction of the pupils6 and focusing on distant obects+acceleration of the heart rate choice 6 and increased force of contraction+ increased sweat

secretion from the sweat glands choice C6+ constriction of cutaneous blood "essels leading to a

reduction of blood flow to the s/in choice 6+ and release of stored lipids from subcutaneousadipose tissue choice 6.

All of the following are derivatives of the amino acid tyrosine ()'(*#

&. opamine

. pinephrine

C. ;elatonin

. :orepinephrine

. Thyro0ine

The correct answer is C. #ome hormones are small molecules that are structurally related to

amino acids. @or e0ample, the following are deri"ati"es of the amino acid tyrosine% dopaminechoice &6, epinephrine choice 6, norepinephrine choice 6 and the thyroid hormones,

thyro0ine choice 6 and triiodothyronine. 8ith respect to the synthesis of norepinephrine, the

following steps apply. The synthesis of norepinephrine begins in the a0oplasm of the terminalner"e endings of adrenergic fibers and is completed inside the "esicles of these fibers. The basicsteps in the synthesis of norepinephrine are as follows% Tyrosine is con"erted to -P& through

the process of hydro0ylation and then -P& undergoes decarbo0ylation to become dopamine.opamine is then transported into the "esicles of the adrenergic fibers where it undergoes

hydro0ylation to become norepinephrine. !n the adrenal medulla, norepinepherine is

transformed into epinephrine through the process of methylation. Choline is combined with&cetyl)Co& to become acetylcholine. ;elatonin choice C6 is a deri"ati"e of the amino acid

tryptophan

All of the following are essential amino acids in adults ()'(*#

&. arginine

. isoleucine

C. leucine

. methionine

. tryptophan

The correct answer is &.&n essential amino acid is one that cannot be synthesied in ade$uate amounts to meet the

needs of the cell and therefore must be supplied by dietary protein. There are 1 essentialamino acids% arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine,

threonine, tryptophan, and "aline. Two of these arginine and histidine6 are consideredAessentialA only in infants and children. & mnemonic to help remember these amino acids is as

follows% A&ny help in learning these little molecules pro"es "aluable


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*hysiology

All of the following are the result of parasympathetic stimulation ()'(*#

&. Contraction of the urinary bladder during urination

. Constriction of the pupils

C. !ncreased heart rate

. !ncreased sali"ary gland secretion

. !ncreased smooth muscle acti"ity of the intestinal tract

The correct answer is C. The parasympathetic and sympathetic ner"ous systems, for the most

part, oppose each other. The maor actions of the parasympathetic ner"ous system are asfollows% ecreased heart rate :-T increased heart rate6+ Contraction of the urinary bladder

during urination choice &6, constriction of the pupils choice 6 increased sali"ary glandsecretion choice 6 and increased smooth muscle acti"ity of the intestinal tract choice 6.

-ther parasympathetic actions include secretion of hormones that promote the absorption andutiliation of nutrients by peripheral cells, stimulation and coordination of defecation,

constriction of the respiratory pathways and se0ual arousal and stimulation of se0ual glands inboth se0es.

All of the following changes in the skeleton are considered agerelated ()'(*#

&. &ppearance of maor "ertebral cur"es

. &ppearance of secondary dentition

C. ecrease in mineral content of the bones

. @usion of epiphyseal plates

. (emodeling of the bone

/ood 0orkThe correct answer is . & re"iew of the human s/eleton can re"eal important information about

an indi"idualEs age and>or se0. owe"er, there are certain characteristics of the human s/eleton

that are independent of an indi"iduals age or se0. @or e0ample, bone remodeling is a process

that occurs throughout a persons life at a relati"ely constant rate. !n the AremodelingA process,

the matri0 of the bone is replaced while lea"ing the bone as whole unchanged. 8ith respect to

indi"idual "ariations in the s/eletal system, the following principles apply% The appearance of

maor "ertebral cur"es occur between the age of 2 fetal months and adulthood choice &6+ The

fetal spine is AbowA shaped and the adult spine is more A#A shaped. The appearance of

secondary dentition choice 6 , occurs when the primary teeth are lost and the permanent

teeth ta/e their place. The mineral content of bone choice C6 typically decreases after the age

of 75. The fusion of epiphyseal plates choice 6 typically occurs near the beginning of

adulthood.

*hysiology

All of the following hormones involved in the regulation of bone growth stimulate

osteoblast activity and the synthesis of bone matri! ()'(*#

&. strogen

. Drowth hormone

C. Parathyroid hormone
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. Testosterone

. Thyro0ine

The correct answer is C. :ormal bone growth and maintenance depend on a combination ofhormonal and nutritional factors. 8ith respect to the hormonal factors, the only hormone

in"ol"ed in the regulation of bone growth, listed as an answer choice, that does not stimulate

osteoblast acti"ity and the synthesis of bone matri0 is parathyroid hormone. Parathyroidhormone is responsible for stimulation of osteoclast acti"ity and ele"ation of calcium ion

concentrations in body fluids. strogen choice &6 secreted in the o"aries, Drowth hormone

choice 6 secreted from the pituitary gland, Testosterone choice 6 secreted from the testes,and Thyro0ine choice 6 secreted from the follicle cells of the thyroid gland, are all responsible

for stimulating osteoblast acti"ity and synthesis of bone matri0 to either a small or large degree

All of the following hormones promote protein synthesis ()'(*#

&. Cortisone

. strogen

C. !nsulin

. Drowth hormone

. Testosterone

The correct answer is &. & summary of protein synthesis is as follows% &n m(:& strand contains

codons that are complementary to the :& strand. The molecules of t(:& contain theanticodons that are complementary to the m(:& codons. ifferent amino acids are then

deli"ered by the t(:&Es. The se$uence of amino acids in the completed peptide will reflect the

se$uence of the t(:& arri"als. The human body then uses these amino acids to build proteins.Cortisone is a glucocorticoid hormone that has the following effects on the peripheral tissues% !t

decreases the use of glucose and releases amino acids from s/eletal muscles and lipids fromadipose tissue. Cortisone also has anti)inflammatory effects. strogens choice 6 and

androgens, such as testosterone, choice 6 are Ase0 hormonesA that increase the rate of aminoacid usage in protein synthesis. !nsulin choice C6 is primarily responsible for increasing glucose

upta/e and utiliation in the li"er, adipose tissue and s/eletal muscle. !nsulin also promotesincreased amino acid upta/e and protein synthesis. This is also one of the primary functions of

growth hormone choice 6.

All of the following statements are true with respect to blood pressure and

resistance to blood flow ()'(*#

&. blood pressure increases with a decrease in arterial elasticity

. resistance to blood flow is directly related to the blood "iscosity

C. resistance to blood flow is directly related to "essel diameter

. stro/e "olume is directly related to blood pressure

. "ascular resistance is directly proportional to the length of the blood "essel

The correct answer is C.

8ith respect to the "ascular system, resistance represents the opposition to the flow of blood. &number of factors can affect blood flow, such as "essel diameter, arterial elasticity, blood

"iscosity, and "essel length. &s the "essel diameter increases, resistance to blood flow willdecrease. !n other words, resistance to blood flow is in"ersely, not directly, related to "essel

diameter.

*hysiology

All of the following statements are true with respect to deglutition ()'(*#

&. appro0imately one)twelfth of all AswallowsA that occur daily occur during sleep

. food is mo"ed to the esophagus under the direction of cranial ner"e F!!

C. in"oluntary contraction of the pharyn0 ad"ances the bolus into the esophagus


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. the nucleus of the solitary tract coordinates the swallowing mechanism

. swallowing is triggered by cranial ner"es *!!! and !F


#wallowing is a refle0 action with its afferent impulses carried primarily by the glossopharyngeal

C: !F6 and "agus C: F6 ner"es. The act of swallowing is triggered by cranial ner"es !F and F,not *!!! and !F. &ll the other statements about deglutition are true. &ppro0imately one twelfthof all daily AswallowsA occur during sleep choice &6, and one)third occur during eating. @ood is

mo"ed to the esophagus under the direction of cranial ner"e F!! choice 6. !n"oluntarycontraction of the pharyn0 ad"ances the bolus into theesophagus choice C6. The nucleus of the

solitary tract coordinates the swallowing mechanism choice 6 "ia the nucleus ambigus andhypoglossal nucleus.

All of the following statements are true with respect to proteins ()'(*#1

&. Proteins are the structural components of androgens

. Proteins are the structural components of antibodies

C. Proteins consist of small organic molecules called amino acids

. Proteins help to create the threedimensional framewor/ of the body

. Protein structures transport materials around the body

The correct answer is &. Proteins perform a "ariety of essential functions in the body+ thesefunctions include the following% The proteins of the immune system are /nown as antibodies. !nother words, proteins are the structural components of antibodies choice 6. Proteins consist of

small organic molecules called amino acids choice C6. The human body contains significant$uantities of about 2 different amino acids. !n fact, these proteins help to create the three)

dimensional framewor/ of the body choice 6. !nsoluble lipids, respiratory gasses, specialminerals, such as iron and se"eral hormones are carried throughout the body attached to

special transport proteins choice 6. Cholesterol is the structural component of androgenschoice &6.

All of the following would lead to an increase in the glomerular filtration rate

()'(*#

&. Constricting the efferent arterioles

. ecreasing plasma protein concentrations

C. ecreasing renin le"els

. ilation of the afferent arteriole

. !nhibition of sympathetic stimulation of the /idney

The correct answer is C. The glomerular filtration rate is defined as the amount of filtrateproduced in the /idneys each minute, which a"erages around 125 m? of filtrate per minute.

There are many different factors that can alter increase or decrease6 the glomerular filtrationrate. @or e0ample, when renin le"els are decreased choice C6, there is a decreased con"ersion

of angiotensin ! to angiotensin !!. #ince angiotensin !! is a potent constrictor of the efferentarteriole, decreasing renin will decrease the D@(. Constricting the efferent arterioles choice &6and dilation of the afferent arteriole choice 6 will directly increase the glomerular filtration

rate. Con"ersely, constriction of the afferent arteriole often occurs when there is a fall in blood

pressure, which will lead to a decrease in the glomerular filtration rate. The constriction of theafferent arteriole occurs when there is sympathetic stimulation of the /idney+ therefore,

inhibition of sympathetic stimulation of the /idney choice 6 will cause glomerular filtration rateto increase. 8hen plasma protein concentrations are decreased choice 6, the /idneys will

increase the glomerular filtration rate to increase the production of urine.

*hysiology


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An alcoholic man is diagnosed with 0ernicke triad and Korsakoff syndrome.

0hich of the following would be the most appropriate treatment for this patient?

&. iotin

. :iacin

C. Pyrido0ine

. (ibofla"in

. Thiamine


The diagnosis of classic 8ernic/e triad ophthalmoplegia, ata0ia, and global confusion6 andorsa/off psychosis is considered to be a medical emergency that necessitates the immediate

administration of thiamine, or "itamin 1. iotin choice &6 acts as a carrier of Aacti"atedcarbo0ylA groups for three /ey enymes that catalye carbo0ylation reactions. #ymptoms of

biotin deficiency are alopecia, s/in and bowel inflammation, and muscle pain. :iacin choice 6,or "itamin 3, is con"erted to nicotinamide, which is then incorporated into the coenymes

:&9 and :&P9. Pellagra is a condition associated with a deficiency of niacin, which can resultin the de"elopment of diarrhea, dermatitis, and dementia. Pyrido0ine choice C6, or "itamin 7,

is associated with the coenyme pyrido0al phosphate. & deficiency in pyrido0ine can lead to thede"elopment of peripheral neuropathy and dermatitis. (ibofla"in choice 6, or "itamin P, is

responsible for maintaining proper le"els of both fla"in mononucleotide @;:6 and fla"in adeninedinucleotide @&6. !ndi"iduals deficient in ribofla"in are li/ely to present with lesions of the lips,

mouth, s/in, and genitalia.

An electrocardiogram showing e!tra * waves before each % comple! indicates

1. fibrillation.

2. atrial bradycardia.

3. partial heart bloc/.

4. "entricular tachycardia.

5. left bundle branch bloc/.

The correct choice is '3, partial heart bloc/. !n order to understand this $uestion you must befamiliar with the normal CD tracings. The P)wa"e is the first wa"e of the CD tracing, and it

represents the spread of depolariation through the atria. The P)( inter"al is measured from thebeginning of the P)wa"e to the beginning of the G(# comple0. !t reflects the time it ta/es for

the depolariation impulse to tra"el from the #)& node to the "entricular myocardium. The P)(segment is measured between the end of the P)wa"e and the beginning of the G(# comple0. !t

reflects the spread of depolariation through the &)* node, the bundle of is and the Pur/inefibers. The G(# comple0 is the second and most important deflection on the CD tracing. !t

represents the spread of depolariation through the "entricular muscle. The #T segment ismeasured from the end of the G(# to the beginning of the T wa"e. !t represents the portion of

the cardiac cycle in which all the "entricular myocardial fibers are depolaried and no furthercurrent flows. The T)wa"e is the third deflection of the G(# and represents the reco"ery period

or repolariation of the "entricles. The G)T inter"al is measured from the beginning of the G(#to the end of the T)wa"e and gi"es the total duration of "entricular systole. Partial heart bloc/

represents a delay in the transmission of the action potential from the atrial pacema/er to the"entricles. This delay may be due to abnormalities in the atria or the &)* node or the bundle ofis, and is reflected by prolongation of the P)( inter"al on the CD. !t is also characteried by

e0tra P)wa"es before each G(# comple0. #o again, the correct choice to $uestion is '3, partialheart bloc/.

An impulse can travel from one nerve to another in only one direction because

the


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1. synapse limits the direction of tra"el.

2. myelin sheath limits the direction of tra"el.

3. myoneural unction limits the direction of tra"el.

4. ner"e fiber permits conduction in only one direction.

5. cell body must be stimulated before the ner"e fiber will conduct.

The correct choice is '1, synapse limits the direction of tra"el. &ction potentials are propagated

along the a0on. The electrical conduction between neurons occurs by gap unctions. Chemical

transmission occurs at the synapse. The neurotransmitter, upon arri"al of the impulse, is

released by the presynaptic neuron and reacts with receptors on the postsynaptic neuron. The

conductance for ions is then increased, and an electrochemical current is propagated. #ince the

presynaptic neuron releases the neurotransmitter upon arri"al of the impulse the impulse is

unidirectional. Due to the synapse the myelin sheath limits the direction of lateral conduction to

adacent ner"es. Conduction along the ner"e fiber itself can be bidirectional, and the ner"e

conducts an impulse due to the am"al of the action potential. #o again, the correct choice is '1,

synapse limits the direction of tra"el.

An individual deficient in which of the following is most likely to develop

pernicious anemia?

&. Cholecysto/in

. Dastrin

C. ydrochloric acid

. !ntrinsic factor

. #ecretin

The correct answer is . !ntrinsic factor is the secretion of parietal cells that facilitates the

absorption of "itamin 12 across the intestinal lining. *itamin 12 is a member of the cobalamin

family and ser"es as a cofactor for two important reactions in humans. &s methylcobalamin, it

ser"es as a cofactor for methionine synthetase in the Con"ersion of homocysteine to

methionine, and as idenosylcobalamin, it ser"es as a cofactor for the sn"ersion of methyl)

malonyl)Co& to succinyl)Co& after being ingested, it becomes bound to intrinsic factor, which is

a protein secreted by gastric parietal cells. -nce absorbed, it is stored in the li"er. The most

common disorder seen with *itamin 12 deficiency is pernicious anemia, which is associated

with the de"elopment of a megaloblastic anemia. This megaloblastic state often leads to "arious

mucosal changes, intestinal disturbances, such as anore0ia and diarrhea, and a neurological

syndrome where the peripheral ner"es are often affected first, causing paresthesias and

difficulty i n balance. Cholecysto/inin choice &6 is produced and stored in the ! cells of the

duodenal and eunal mucosa. The parietal cell secretes two substances% intrinsic factor and

hydrochloric acid. The hormone gastrin choice 6, which is produced in the D cells of the

duodenum, primarily functions to stimulate hydrochloric acid, histamine, and pepsinogen

secretion as well as increase gastric blood flow. ydrochloric acid choice C6 functions primarily

to denature proteins and acti"ate digesti"e enymes. #ecretin choice 6 is synthesied and

stored in the # cells of the upper intestine. !t stimulates the secretion of bicarbonate containing

substances from the pancreas and inhibits gastric emptying and gastric acid production.


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An individual that has antiA agglutinins and h agglutinogens would have which

of the following classifications of blood?

&. Type & negati"e

. Type & positi"e

C. Type negati"e

. Type positi"e

. Type & positi"e

The correct answer is . There are two antigens type & and type 6 that appear on the surfaces

of red blood cells. @urthermore, strong antibodies that react specifically with either the type & or

type antigens, occur in indi"iduals who do not ha"e these particular antigens on their cells.

ence, type & and type antigens are called agglutinogens and the antibodies that cause

agglutination are called anti &> agglutinins. &long the same lines, indi"iduals who ha"e the (h

agglutinogen will be (h9, and those without the (h agglutinogen will produce the anti)(h

agglutinin. (emember that agglutinogens are antigens, and agglutinins are antibodies. &n

indi"idual that has anti)& agglutinins and (h agglutinogens would ha"e a Type 96 blood

classification. -ne would e0pect to see anti agglutinin and no (h agglutinogen in a person with

type & )6 blood choice &6, con"ersely anti) agglutinin and (h agglutinogen choice 6 is seen

in persons with & 96 blood. &nti)& agglutinin and no (h agglutinogen choice C6 is seen in )6

blood types. 8hen there are no anti)& or anti) agglutinins the person has both agglutinogens6

and there is (h agglutinogen, the person has blood type of & positi"e choice 6.

An individual who is chronically lethargic& unable to adust to cold temperatures

and has chronic dry skin is most likely deficient in of which of the following

hormones?

&. Calcitonin

. Drowth hormone


. Testosterone

. Thyroid hormone

The correct answer is . &dults with hypothyroidism are chronically lethargic, unable to adust to

cold temperatures and often ha"e chronically dry s/in as well as ha"e some degree of hair loss,

muscle wea/ness and slowed refle0es. !n other words, the patient in this $uestion is most li/ely

deficient in their thyroid hormones, since the effects of thyroid hormones are as follows%

le"ation of o0ygen consumption and the rate of energy consumption+ increased heart rate+

stimulation of acti"ity of other endocrine tissues+ maintenance of sensiti"ity of respiratory

centers as well as "arious other functions. Calcitonin choice &6 is the hormone primarily

responsible for the regulation of calcium ion concentrations in the blood. 8hen blood le"els of

calcium ions become ele"ated, calcitonin is secreted to reduce calcium ion le"els to normal

limits+ Therefore, deficiencies of calcitonin would result in the de"elopment of hypercalcemia.

Drowth hormone choice 6 stimulates cell growth and replication by accelerating the rate of

protein synthesis. !ndi"iduals deficient in growth hormone are often described as Apituitary


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dwarfsA. Parathyroid hormone choice C6 is responsible for increasing calcium ion concentrations

in the body fluids+ therefore indi"iduals deficient in this hormone would most li/ely be

hypocalcemic. Testosterone choice 6 promotes the production of functional sperm, maintains

the secretory glands of the male reproducti"e tract and stimulates growth. eficiencies of

testosterone are associated with a decreased de"elopment of male secondary se0

characteristics.

An inflammatory response is triggered when which of the following occur?

&. lood flow to an area increases

. Clot formation occurs

C. @ibroblasts secrete beta)interferon

. ;ast cells release histamine

. :eutrophils phagocytie bacteria

The correct answer is . !nflammation is a localied tissue response to inury that produces

"arious local sensations, such as swelling, heat, redness and pain. There are many different

factors that can cause inflammation, including abrasion, impact, irritation, and infection. ;ast

cells play an important role in the inflammation process. These cells release histamine,

prostaglandins, heparin and other chemicals into the immediate area. 8hen histamine is

released, capillary permeability is increased and blood flow to the area increases. &lthough

blood flow to the area choice &6 is the most common cause of inflammation, the inflammatory

response is triggered when mast cells release histamine. Clot formation choice 6 is one of the

final states of tissue repair+ it does not promote inflammation. 8hen fibroblasts secrete beta)

interferon, this substance slows the inflammation process in damaged tissue. 8hen neutrophils

phagocytie bacteria choice 6, inflammation is not promoted

An inflammatory response is triggered when which of the following occur?

&. lood flow to an area increases

. Clot formation occurs

C. @ibroblasts secrete beta)interferon

. ;ast cells release histamine

. :eutrophils phagocytie bacteria

The correct answer is . !nflammation is a localied tissue response to inury that produces

"arious local sensations, such as swelling, heat, redness and pain. There are many different

factors that can cause inflammation, including abrasion, impact, irritation, and infection. ;ast

cells play an important role in the inflammation process. These cells release histamine,

prostaglandins, heparin and other chemicals into the immediate area. 8hen histamine is

released, capillary permeability is increased and blood flow to the area increases. &lthough

blood flow to the area choice &6 is the most common cause of inflammation, the inflammatory

response is triggered when mast cells release histamine. Clot formation choice 6 is one of the

final states of tissue repair+ it does not promote inflammation. 8hen fibroblasts secrete beta)

interferon, this substance slows the inflammation process in damaged tissue. 8hen neutrophils

phagocytie bacteria choice 6, inflammation is not promoted.


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Antidiuretic hormone acts to

1. decrease renal filtration fraction.

2. increase storage capacity of the bladder.

3. decrease permeability of distocon"oluted tubules and>or collecting ducts to water.

4. increase permeability of distocon"oluted tubules and>or collecting ducts to water.

The correct choice is '4, increase permeability of distal con"oluted tubules and>or collectingducts to water. 8hen plasma osmotic pressure changes the brainEs osmoreceptors respond by

stimulating or inhibiting antidiuretic hormone, abbre"iated &. &0ons of neurons in thesupraoptic and para"entricular nuclei of the anterior hypothalamus e0tend down the pituitary

stal/ to the posterior lobe of the pituitary, where the a0on terminals release secretory productsinto the blood. *asopressin, or &, is one of the two hormones released. The other is o0ytocin.

& binds to specific cell receptors of the distal con"oluted tubule and the collecting duct,

acti"ating adenylate cyclase+ C&;P is produced, followed by acti"ation of protein /inase. 8aterthen flows across the cell, due to the phosphorylation of lumenal membrane components. or collecting ducts to water.

Avidin influences which of the following vitamins?

1. :iacin

2. iotin

3. Thiamine

4. Tocopherol

5. Phyllo$uinone

The correct answer is choice 2. &"idin, which is a glycoprotein found in egg white, can produce

biotin deficiency as it binds biotin tightly, pre"enting its absorption from the intestine. !t has no

effect on any of the other choices. Choice 1, niacin, is in"ol"ed in producing :& and :&P and

niacin deficiency leads to pellagra. Choice 3, thiamin, or "itamin 1 deficiency, causes beriberi.

Thiamin acts as a co)enyme in reactions in"ol"ing aldehyde groups. Tocopherol, or "itamin

deficiency, is related to infertility, and "itamin has antio0idant properties. Choice 5,

phyllo$uinone, is a member of the $uinone family. Guinones are in"ol"ed in electron transport in

the respiratory chain. #o the correct answer to $uestion is choice 2.

$acteria in the intestinal tract are responsible for synthesis of all the following

()'(*#

&. ammonia

. ascorbic acid

C. folic acid

. small organic acids

. "itamin


!n normal feces, 3H of the solid waste may be composed of bacteria. !n the intestinal tract,bacteria split urea to form ammonia choice &6 and synthesie folic acid choice C6, small


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organic acids choice 6 from unabsorbed fat and carbohydrates, and "itamin . The brown

color of feces is mainly due to the action of bacteria on bile pigments. The odor of feces is due

to sulfides and indolic compounds. &scorbic acid choice 6, or "itamin C, is :-T produced by

the bacteria in the intestinal tract.

*hysiology

$oth control and regulation of sympathetic function primarily occur in centers in

the

&. cerebellum

. cerebrum

C. mesencephalon

. posterior and lateral hypothalamus

. spinal cord and adrenal medulla

/ood 0orkThe correct answer is . The autonomic ner"ous system consists of two subdi"isions, the

sympathetic and parasympathet ner"ous systems. !n summary, an increase sympathetic acti"ity

leads to stimulation of tissue metabolism, increased alertness and preparation of the body for an

emergency. The sympathetic di"ision consists of preganglionic neurons located between spinal

segments T! and ?2. @urthermore, the ganglionic neurons are also located in ganglia near the

"ertebral column. The center of each adrenal gland adrenal medulla6 is a modified sympathetic

ganglion. !n other words, both control and regulation of sympathetic function primarily occurs in

centers in the spinal cord and adrenal medulla. The cerebellum choice &6 adusts "oluntary and

in"oluntary motion acti"ities as well as compares incoming sensory information with anticipated

sensations. Consciousness, thought processes, sensations, intellectual function, memory storage

and retrie"al and comple0 motion actions originate in the cerebrum choice 6. The

mesencephalon choice C6 is the center responsible for processing "isual and auditory

information. The posterior and lateral portion of the hypothalamus choice 6 contain "arious

centers in"ol"ed with emotions, autonomic function and hormone production. @urthermore, the

hypothalamus is the primary lin/ between ner"ous and endocrine system.

*hysiology

$reathing a gas mi!ture with percent '52& ultimately leads to which of the

following?

&. ypo"entilation

. & decrease in heart rate

C. & stimulation of central chemoreceptors

. &n inhibition of peripheral chemoreceptors

. & decrease in cerebrospinal fluid hydrogen)ion concentration
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The correct answer is Choice C. C2 has a direct effect on the respiratory center of the brain incontrolling respiration. reathing a gas mi0ture with e0cess C2 will stimulate control

chemoreceptors Choice C6 to cause increased strength of pulmonary "entilation, thus reducing

C2 concentration by e0piring greater amounts of C2 out of the body.Choice & is incorrect as an e0cess amount of C2 will ultimately lead to hyper"entilation as the

lungs labor to rid the body of C-2.

Choice is also incorrect as C2 concentration in the blood can stimulate peripheral

chemoreceptors especially at the onset of e0ercise. !t will not, howe"er, inhibit peripheralchemoreceptors as stated in this choice. Choice is incorrect as e0cess C2 can pass through

the blood)cerebrospinal fluid barrier, react with water present to form hydrogen ions thus

increasing the hydrogen ion concentration in the cerebrospinal fluid.

*hysiology

'alcium ions initiate contraction in skeletal muscle when they

&. bind to T tubules.

. bind to troponin.

C. interact with actin.

. interact with myosin.

. bind to sarcoplasmic reticulum

The correct answer is Choice . Calcium ions bind strongly to troponin Choice 6 changing the

condition between troponintropomyosin comple0 and actin in the rela0ed muscle state to

produce a new relationship that leads to muscle contraction.

T)tubule Choice &6 facilitates transmission of action potentials to all s/eletal muscle fibers. !t

does not bind with calcium ions.

Calcium ions also do not bind with actin choice C6 or myosin Choice 6. &ctin must attach to

the heads of the myosin filaments to cause contraction.

#arcoplasmic reticulum Choice 6 releases calcium ion in the "icinity of all myofibrils to bring

about contraction.

'alcium ions trigger contraction of muscles by binding to

1. actin.

2. myosin.

3. troponin.

4. tropomyosin.

The correct answer is choice 3, troponin. uring muscular contractions, the hea"y meromyosin

subunit of myosin e0tends to reach and bind with the actin filament. This binding acti"ates the

&TPase acti"ity of the myosin head and in the presence of &TP, a confirmational change may

occur in the end causing a spring li/e shortening. This results in pulling the actin filament past

the myosin filament. Tropomyosin on the actin molecule co"ers the binding site for myosin cross

bridges in the absence of calcium ion.8hen calclum ion is present, it binds to troponin and

e0poses the binding site on the actin molecule for myosin to interact and allows the contraction

cycle to occur. Choice 1 is incorrect. &ctin is a maor protein found in the thin filament of the

myofibril. Choice 2 is incorrect. ;yosin is large protein consisting of two sets of light chains and

one set of hea"y chain composing the thic/ filament. Choice 4 is incorrect. Tropomyosin is found

in the thin filament. These rod shaped molecules are associated with actins to form the basic

structural component of the thin filament. #o the correct answer to $uestion is

choice 3.


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'arbohydrate is stored in the body principally as

1. glucose.

2. maltose.

3. sucrose.

4. glycogen.

5. glycosaminoglycans.

The correct choice is '4, glycogen. Dlycogen is stored in the li"er. &t times, when glucose is in

demand glycogen will be con"erted into glucose "ia glycogenolysis, which is the lysis of

glycogen, or stored carbohydrate. pinephrine, or glucagon, stimulates the con"ersion of &TP to

cyclic &;P "ia adenylate cyclase. Cyclic &;P then con"erts protein /inase inacti"e to protein

/inase acti"e. Protein /inase aids in the phosphorylation of phosphorylase /inase inacti"e to

phosphorylase /inase acti"e "ia &TP. The phosphorylase /inase acti"e then con"erts to

phosphorylase) inacti"e to phosphorylase)& acti"e. This then releases successi"e glucose)1)

phosphate residues from the branch chains of glycogen. Thus, we ha"e the production of

glucose from our stored carbohydrate. #o again, the correct choice is 4, glycogen.

'arbon mono!ide decreases the amount of

1. bicarbonate in the blood plasma.

2. carbonic anhydrase a"ailable in the lungs.

3. o0ygen that can be transported by hemoglobin.

4. al"eolar surface a"ailable for gaseous e0change.

5. carbon dio0ide that can be transported by the blood.

The correct answer is '3, o0ygen that can be transported by hemoglobin. Carbon mono0ide

combines with ferromyoglobin and ferrohemoglobin, interfering with o0ygen transport. eme

has a high affinity for carbon mono0ide. ;yoglobin and hemoglobin ha"e less affinity than the

isolated heme. owe"er, they still bind. These proteins decrease the affinity of carbon mono0ide

to the heme)protein comple0 by sterically hindering the binding of carbon mono0ide. ;ore

specifically, the myoglobin and hemoglobin change the geometry of the binding of carbon

mono0ide from that of the protein)o0ygen binding and in doing so wea/ens the interaction of

carbon mono0ide with the heme, optimiing -2 binding. :e"ertheless, carbon mono0ide has a

greater affinity for binding than o0ygen, and this fact decreases the amount of o0ygen that can

be transported by hemoglobin. #o again, the correct choice is '3, o0ygen that can be

transported by hemoglobin.

'ardiac muscle differs from the other types of muscle tissue in that cardiac

muscle


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&. Contains "isible striations

. @orms muscle fibers

C. as both actin and myosin filaments

. as only one nucleus per cell

. !s able to contract without neural stimulation

0orkThe correct answer is . There are three types of muscle tissue in the human body% cardiac,

s/eletal and smooth muscle. &ll of these types of muscle tissue are specialied for contraction.

ach of these types of muscle is designed to perform specific functions in the body. @or

e0ample, cardiac muscle is found only in the heart and functions to circulate blood and maintain

blood pressure. This type of muscle differs from s/eletal and smooth muscle in that it is able to

contract without neural stimulation. 8ithin the cardiac muscle are specialied muscle cells called

pacema/er cells, which establish a regular rate of contraction. &lthough the ner"ous system

may alter the rate of pacema/er acti"ity, it does not pro"ide AcontrolA o"er the cardiac muscle

cells. *isible striations choice &6 are found in both s/eletal and cardiac muscle. oth cardiac

and s/eletal muscle form muscle fibers choice 6. &ctin and myosin filaments choice C6 are

found in all three types of muscle. &lthough cardiac and smooth muscle contain one nucleus

choice 6, s/eletal muscle cells may contain hundreds of nuclei per cell

*hysiology

'ell bodies of sympathetic preganglionic neurons are located in

1. dorsal root ganglia.

2. sympathetic chain ganglia.

3. the brain stem and the spinal cord.

4. thoracic and lumbar segments of the spinal cord.

5. none of the abo"e.

The correct answer is choice 4. ?etEs re"iew the location of the cell bodies of pre) and post)

ganglionic neurons of the sympathetic and parasympathetic ner"ous systems. !n thesympathetic ner"ous system, pre)ganglionic cell bodies are located in thoracic spinal segments

T1 through T12 and lumbar segments ?1 through ?3 or 4. ;ost of these neurons synapse insympathetic ganglia in the sympathetic ganglion chain. ere, the post)ganglionic ner"es

originate and the post)ganglionic cell bodies are located in thc sympalhctic chain. These post)

synaptic neurons tra"el a much longer distance than the pre)synaptic neurons, ending near theeffector muscle or gland. !n the parasympathetic system, the pre)ganglionic cell bodies are

located in the mid)brain or medulla or the sacral regions of the spinal cord, sections #1 through

#5. They synapse in ganglia far from the spinal cord, but near the effector musclc or gland. #ochoice 1 is incorrect. orsal root ganglia contain cell bodies of afferent neurons. Choice 2 is

incorrect and is the location of cell bodies of the sympathetic post)synaptic neurons. Choice 3 isincorrect and is the location of pre)ganglionic parasympathetic cell bodies. #o the correct

answer to $uestion is choice 4.

'holesterol is primarily used by mammalian cells as

1. an energy storage material.

2. a precursor of /etone bodies.


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3. a component of cell membranes.

4. a precursor of polyunsaturated fatty acids.

The correct answer is choice 3, a component of cell membrane. Cholesterol, which can be

deri"ed from the diet or manufactured de no"o in "irtually all of the cells of the human body,

plays a number of important roles. The first role of cholesterol is ! that it is the maor sterol in

humans and a component of "irtually all cell membranes and intracellular membranes. The

second role of cholesterol is as the immediate precursor of the bile acid. The third physiological

role of cholesterol is as the precursor of the "arious steroid hormones. #o the correct answer to

$uestion is choice 3

*hysiology

'hondroitin sulfate occurs primarily in

1. bile.

2. blood.

3. li"er.

4. urine.

5. cartilage.

/ood 0orkThe correct answer is choice 5. Chondroitin sulfate is in the chemical family of acid

mucopolysaccharides which includes hyaluronic acid. &s chondroitin 4)sulfate or chondroitin)&,

and chondroitin 7)sulfate or chondroitin)C, chondroitin sulfates ma/e up a large percentage ofcartilage, bone and cornea structure. -f the other answer choices, it should be noted that a

related acid mucopolysaccharide is heparin which pre"ents coagulation of blood and is found in

arterial walls and in the lungs. #o the correct answer to $uestion is choice 5

.'linical adult onset diabetes mellitus 6#ype 778 results from

1. deficient secretion of insulin.

2. e0cess secretion of epinephrine.

3. failure of the /idneys to retain sugar.

4. secretion of o0ytocin from the posterior pituitary.

5. loss of the insulin receptor function in the target tissues.

The correct answer is choice 5, loss of the insulin receptor function in the target tissues. :on)

insulin)dependent diabetes mellitus, which accounts for B)IH of the diagnosed cases of

diabetes, is also called adult onset diabetes to differentiate it from insulin)dependent u"enile

diabetes. !t usually occurs in middle aged, obese people. !nsulin is present at near normal to

ele"ated le"els in this form of the disease. The defect in these patients lies in the loss of the

insulin receptor function. (eceptors are normally located on the plasma membranes of normally

insulin) responsi"e cells, that is, hepatocytes, adipocytes and muscle cells. !nsulin)dependent

diabetes mellitus is also called u"enile onset diabetes or diabetes mellitus !, because it usually

appears in childhood or the teens, but it is not limited to these patients. !nsulin is either absent

or nearly absent in this disease because of defecti"e or absent beta cells in the pancreas. Choice


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1 is incorrect. eficient secretion of insulin would be associated with diabetes mellitus !. Choice

2 is incorrect as e0cess secretion of epinephrine does not lead to either form of diabetes. Choice

3 is incorrect. #ugar in the urine is due to e0cretion of the large $uantity of plasma glucose

present in diabetes. This is a normal function of the /idney. Choice 4 is incorrect. -0ytocin

release is connected with uterine contraction and is not connected with either form of diabetes.

#o the correct answer to $uestion is choice 5. 9$,( *art 7 released :uestions

$iochemistry*hysiology

'orti+s organ is responsible for perception of

1. light.

2. sound.

3. taste.

4. temperature.

5. proprioception.

The correct answer is choice 2. The organ of Corti is a spiral)shaped organ within the cochlea ofthe ear. !t contains hair cells which are the auditory receptor cells. #ensation from the hair cells

tra"els along the auditory or cochlear di"ision of the "estibulocochlear acoustic ner"e whichterminates in the cochlear nuclei of the medulla. #o the correct answer to $uestion is choice 2.

9$,( *art 7 released :uestions $iochemistry*hysiology

,ecreased arterial pressure upon standing is compensated by

&. decreased heart rate.

. dilation of mesenteric "essels.

C. constriction of systemic arterioles.

. dilation of "enules

The correct answer is Choice C. !mmediately upon standing from a prone or supine position, apersonEs arterial blood pressure in the head and upper part of the body tends to fall. The

baroreceptors located in the walls of large systemic arteries compensate by eliciting strong

sympathetic discharge throughout the body resulting in constriction of systemic arteriolesChoice C6 and thus raising blood pressure. ecreased heart rate Choice &6, dilation of

mesenteric "essels Choice 6, and dilation of "enules Choice C6 will all decrease bloodpressure further which is undesirable in this case.

,ecreased response of sense organs when e!posed to a constant stimulus is

called

&. occlusion.

. summation.

C. adaptation.

. facilitation.

. sensory depri"ation.

The correct answer is Choice C. & common characteristic that applies to all sensory organs is

that their response to a constani stimulus decreases after a period of time. This special trait is

/nown as adaptation Choice C6. &daptation occurs in all sensory receptors but to different
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e0tents and by different mechanisms.

Choice & occlusion as a general term refers to the act of closing or the state of being closed. !t

does not describe sensory organ response to stimuli.

Choice summation often refers to the additi"e effect of fre$uent repetiti"e stimuli applied to

ner"e terminals to achie"e e0citation. &gain, it does not in"ol"e sensory organs or their

response.

Choice facilitation is the enhancement or reinforcement of a ner"ous acti"ity by the arri"al of

signals from other neurons.

Choice sensory depri"ation occurs when some or all usual e0ternal stimuli are absent. !t will

often result in psychological stress and abnormal beha"ior. !t also does not apply to sensory

receptors response to stimuli

,ental pla:ue arises primarily as a result of enzymatic reactions using which of

the following?

1. #ucrose and lipid

2. #ucrose and sali"a

3. Dlucose and sali"a

4. Dlucose and protein

The correct answer is choice 2. -ne of the few dental $uestions on this e0am, you should

recognie that the maor carbohydrate substrate and energy source of pla$ue is sucrose, not

glucose. !n addition, the sali"ary proteins are often in"ol"ed in aiding the pla$ue to adhere to

tooth structure. !n general, lipids are not highly in"ol"ed in pla$ue formation, so choice 1 is

incorrect. Choices 3 and 4 are incorrect because they include glucose and not sucrose. #o the

correct answer to $uestion is choice 2.

,estruction of the cerebellum causes loss of

1. memory.

2. "ision.

3. hearing.

4. muscular coordination.

5. both 26 and 36 abo"eThe correct answer is choice 4. The cerebellum acts to coordinate "oluntary muscular acti"ity.

Choice 1 is incorrect. ;emory function is located within the cerebral corte0, especially in the

temporal lobes. Choice 2 is incorrect. *isual function within the brain is located within the "isual

corte0 of the cerebrum in the occipital lobes. Choice 3 is incorrect. earing function is located

within the cerebral corte0 in the area of the auditory corte0 of the temporal lobes. #o the


,evelopment of ovarian follicles to the point of ovulation is stimulated primarily

by

1. estrone.

2. progesterone.


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3. luteiniing hormone.

4. follicle)stimulating hormone.

5. chorionic gonadotropic hormone.,evelopment of ovarian follicles to the point of

ovulation is stimulated primarily by

1. estrone.

2. progesterone.

3. luteiniing hormone.

4. follicle)stimulating hormone.

5. chorionic gonadotropic hormone.

,uring an automobile accident& a child+s posterior pituitary is severely damaged.

0hich of the following would most likely be seen?

&. &ddison disease

. ecreased s/in pigmentation

C. ecreased thyroid function

. iabetes insipidus

. warfism

This is a 3)step $uestion. @irst, you need to /now which hormones are produced in the posterior

pituitary+ then /now the function of each hormone+ and finally /now which pathologic condition

will follow when this AparticularA hormone is absent. The posterior pituitary produces antidiuretic

hormone &, or "asopressin6 and o0ytocin. & is responsible for maintaining plasmaosmolarity and pre"enting e0cessi"e water loss. 8hen & is absent, diabetes insipidus can

result. This condition is caused by a decrease in the renal reabsorption of water, an increase in

serum osmolarity, and the generation of a dilute hypotonic6 urine. &ll the other conditions can

result from a decrease in the secretions of the anterior pituitary. &ddison disease choice &6 is

caused by decreased production of corticosteroids, such as cortisol. The production is decreased

secondary to a decrease in the secretion of &CT. ecreased s/in pigmentation choice 6 can

occur when melanocyte)stimulating hormone is not secreted. 8hen thyroid)stimulating hormone

T#6 is not secreted, you can e0pect to see a decreased thyroid function choice C6. warfism

choice 6 is a condition that can occur in young children when growth hormone production is

decreased.

,uring e!tended periods of fasting& all of the following are able to utilize ketones

and;or fatty acids as a fuel source ()'(*#

&. the brain

. cardiac muscle

C. the li"er

. s/eletal muscle

. red blood cellsThe correct answer is .

Patterns of fuel utiliation depend on the metabolic state well)fed "ersus fasting6 and on the


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indi"idual tissue. ;ost cells in the body are able to utilie different fuels during the fasting state,

e0cept red blood cells. (ed blood cells are only able to utilie glucose as a fuel source. &lthough

glucose is the primary fuel for the brain choice &6, during periods of fasting, this organ can

utilie /etone as an energy source. The primary source of fuel for cardiac muscle choice 6 is

glucose and fatty acids. owe"er, cardiac muscle can utilie /etones during periods of fasting.

The li"er choice C6 prefers to utilie glucose and amino acids+ howe"er, it can utilie glycogen,

lactate, glycerol, fatty acids, and amino acids. #/eletal muscle choice 6 can utilie glucose, as

well as fatty acids and /etones.

,uring periods of fasting or starvation& an increased production of ketone bodies

leads to

&. ecreased blood p

. iabetes

C. !ncreased blood p

. !ncreased protein brea/down

. #/eletal muscle brea/down

The correct answer is &. & /etone body is also referred to as a /eto acid since it dissociates in

solution releasing a hydrogen ion. &s a result, the appearance of /etone bodies in circulation will

decrease the blood p, ma/ing it more acidic. This acidification process is referred to as

/etoacidosis. etone bodies are produced as a result of lipid and amino acid brea/down during

periods of fasting or star"ation 8hen e0cessi"e amounts of /etone bodies are formed, the

pathological state /nown as /etoacidosis can occur. etoacidosis occurs most commonly in

patients with diabetes choice 6. :ote% iabetes can lead to /etoacidosis, not "ise "ersa.

etoacidosis would not increase protein brea/down choice 6 or s/eletal muscle production.

,uring periods of moderate e!ercise& one would e!pect to see all of the following

()'(*#

&. decreased carbon dio0ide production

. increased o0ygen consumption

C. increased pulmonary blood flow

. increased "entilation rate

. no change in arterial p

The correct answer is &.

uring periods of e0ercise, a number of physiologic changes occur that account for the

increased o0ygen demand in the body. uring periods of moderate e0ercise, one would e0pect

to find an increased, not decreased, production of carbon dio0ide. There is an increased o0ygen

consumption choice 6, increased pulmonary blood flow choice C6, and increased "entilation

rate choice 6. !n addition, there is no change in arterial p choice 6+ howe"er, one may see

a decrease in arterial p during periods of strenuous acti"ity.


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,uring red blood cell recycling each heme unit is stripped of its iron and

immediately converted to1

&. bilirubin

. bili"erdin

C. ferritin

. transferrin

. urobilin

The correct answer is . &n erythrocyte is e0posed to se"ere mechanical stresses o"er the

course of its life. & single round)trip of the circulatory system for an erythrocyte often ta/es less

than 3 seconds. uring this time period it is bounced off "essel walls and s$ueeed through

tiny capillaries. 8ith all this wear and tear and no repair mechanisms, the red blood cell has a

relati"ely short life span. &s the AoldA red blood cells are bro/en down and recycled, each

component of the hemoglobin has a different fate. @or e0ample, during this red bloodcel

recycling each heme unit is stripped of its iron and immediately con"erted to bili"erdin.

ili"erdin is a porphyrin deri"ati"e with a green color. The bili"erdin is then con"erted into

bilirubin choice &6 which is found in the general circulation. ?i"er cells absorb the bilirubin and

use it to synthesie a comple0 molecule, conugated bilirubin, which is e0creted in the bile.

Transferrin choice 6 is a plasma protein to which e0cessi"e iron is bound. (ed blood cells

de"eloping in the bone marrow absorb amino acids and transferrins from circulation and use

them to synthesie new hemoglobin molecules. 0cessi"e transferrins are remo"ed by the li"er

and bone marrow and the iron is then stored in two special protein)iron comple0es, ferritin

choice C6 and hemosiderin. !nside the large intestine, bacteria will con"ert the conugated

urobilin to urobilogen. 8hen e0posed to o0ygen, the urobilinogen is con"erted to urobilin

choice 6 which is the substance that gi"es urine its yellow color.

,uring which of the following phases of the cardiac cycle are all cardiac valves

open?

1. (apid filling

2. arly eection

3. lso"olumic rela0ation

4. lso"olumic contraction

5. :one of theseThe correct answer is choice 5, none of the abo"e. uring atrial systole, a

small amount of blood is pumped into the "entricles. The semilunar "al"es are closed and the

&* "al"es are then opened to pro"ide a funnel for the transfer of blood from atrium to "entricle.

This continues until the "entricular pressure e0ceeds the atrial pressure and causes the &*

"al"es to close during "entricular systole. *entricular systole causes the semilunar "al"es to

open when "entricular pressure e0ceeds pulmonary and aortic diastolic pressure, thus beginning

the period of isotonic contraction during which blood is eected into the outflowing trun/. 8hen

pulmonary and ! aortic pressures e0ceed end systolic "entricular pressure, it causes the

semilunar "al"es to close. #o in summary there is no point at which all "al"es are open at the

same time. Choice 1 is incorrect. uring rapid filling. &* "al"es are open, semilunar "al"es are

closed. Choice 2 is incorrect. uring early eection, semilunar "al"es are open but &* "al"es are


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closed. Choice 3, iso"olumetric rela0ation, semilunar "al"es are closed. Choice 4, iso"olumetric

contraction, &* "al"es are closed. #o the correct answer to $uestion again, is choice 5.

(levated levels of calcium ions in the blood stimulates the secretion of which of

the following?

&. Calcitonin

. Drowth hormone


. Testosterone

. Thyroid hormone

The correct answer is &. Calcitonin is the hormone primarily responsible for the regulation of

calcium ion concentrations in the blood. 8hen blood le"els of calcium ions become ele"ated,

calcitonin is secreted to reduce calcium ion le"els to normal limits. Drowth hormone choice 6

stimulates cell growth and replication by accelerating the rate of protein synthesis. Parathyroid

hormone choice C6 is responsible for increasing calcium ion concentrations in the body fluids+

therefore, this hormone would not be secreted in an indi"idual with hypercalcemia. Testosterone

choice 6 promotes the production of functional sperm, maintains the secretory glands of the

male reproducti"e tract and stimulates growth. The effects of thyroid hormones choice 6 are

as follows% le"ation of o0ygen consumption and the rate of energy consumption+ increased

heart rate+ stimulation of acti"ity of other endocrine glands+ maintenance of sensiti"ity of

respiratory centers as well as "arious other functions.

(motional feelings are


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(nergy for A#* synthesis is derived from the electron transport system by which

of the following processes?

1. Transamination

2. &ldoliation

3. (educti"e synthesis

4. -0idati"e deamination

5. -0idati"e phosphorylation

The correct choice is '5, o0idati"e phosphorylation. -0idati"e phosphorylation is necessary for

all cells that deri"e energy "ia aerobic o0idation. ;itochondria, the powerhouses of the cell, are

the locations of the o0idati"e phosphorylation and electron transport enymes. The mitochondria

ha"e two membranes, the inner membrane and the outer membrane. The inner membrane

contains cytochromes b, c, c1, a and a3, and the @&TP)ase associated with the mechanism of

o0idati"e phosphorylation. Proof has been established that electron transport from :& to

o0ygen is the main source of energy used for the completed phosphorylation of &P, so the

correct answer is '5, o0idati"e phosphorylation.

(stablishing a tracheostomy results in

1. increased airway resistance.

2. increased anatomic dead space.

3. increased physiologic dead space.

4. decreased respiratory wor/.

5. decreased effecti"e al"eolar "entilation.

The correct answer is choice 4, decreased respiratory wor/. &natomic dead space is that part of

the conducting airway in which almost no gas e0change occurs. This includes the trachea, the

main stem bronchi, and their subdi"isions. This anatomic dead space is decreased by

tracheostomy because of remo"al or bypass of some of the conducting airway. !n doing so, the

wor/ of breathing which is defined as P *, pressure 0 the change in "olume, is decreased

because "olume is decreased. Choice 1 is incorrect. ;ost of the turbulence to air flow is in the

trachea and therefore bypassing the trachea results in decreased airway resistance. Choice 2 is

incorrect. The trachea is part of the anatomic dead space. Tracheostomy actually decreases and

not increases the anatomic dead space. Choice 3 is incorrect. Physiologic dead space J the

anatomic dead space plus the "olume of air that reaches the al"eoli but does not come into

contact with pulmonary capillary blood and therefore does not participate in gas e0change.

Choice 5 is incorrect. ffecti"e al"eolar "entilation is "entilation that occurs at the gas e0change

surfaces of the al"eoli. & tracheostomy does not affect the effecti"e al"eolar "entilation. #o the


(!cluding the effect of drugs& apnea occurring after hyperventilation of an

anesthetized patient results from


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1. decreased demand for o0ygen.

2. increased cerebral blood flow.

3. decreased carbon dio0ide tension.

4. increased hydrogen ion concentration

5. decreased o0ygenation of carotid bodies.

The correct answer is choice 3. The term AapneaA refers to respiratory arrest, a time period

during which breathing ceases. (espiratory acti"ity is stimulated by the C2 le"el of the blood

as sensed by chemoreceptors in the medulla. !t is also triggered by 2 le"els as sensed by the

aortic and carotid bodies. 8hen a patient is hyper"entilated, sufficient o0ygen can be ta/en in,

but e0cess C2 may be released from the blood. ?ow C2 le"el will then fail to stimulate the

medullary chemoreceptors. Choice 1 is incorrect. yper"entilation will not cause decreased

o0ygen demand. Choice 2 is also incorrect as hyper"entilation does not increase cerebral blood

flow. Choice 4 is incorrect. yper"entilation will cause loss of C2 which causes acid loss or

increased p or respiratory al/alosis. Choice 5 is incorrect as well. ecreased o0ygenation would

not occur during hyper"entilation and decreased o0ygenation of thc carotid bodies should

increase respiration, not cause apnea. #o the correct answer to $uestion is choice 3.

=ollowing an antineoplastic treatment regimen& a patient+s uric acid level

increases dramatically. #herefore& this individual would derive the most benefit

from an agent that inhibits the action of which of the following enzymes?

&. &lpha)glucosidase

. &ngiotensin)con"erting enyme

C. eta)lactamase

. Cycloo0ygenase

. Fanthine o0idase


&fter selected antineoplastic therapies, patients can ha"e a high le"el of urate secondary to the

brea/down of nucleic acids. Therefore, they are often administered allopurinol to decrease

plasma urate le"els. &llopurinol pre"ents the formation of uric)acid by inhibiting the

enym/0anthine o0idase. ecreasing uric acid le"els will help pre"ent the formation of /idney

stones, as well as bloc/ the appearance of other deleterious effects of hyperuricemia. &carbose

is an agent used in the treatment of type 2 diabetes. This agent inhibits the acti"ity of alpha)

glucosidase choice &6 in the intestinal tract, thereby helping to pre"ent postprandial surges of

hyperglycemia. !nhibition of angiotensin)con"erting enymes choice 6 will result in a lowering

of blood pressure and aid in the pre"ention of the "entricular remodelingn that occurs secondary

to congesti"e heart failure. eta)lactamase choice C6 inhibitors are combined with peniciliin

antibiotics to help impro"e their acti"ity against bacteria that produce the enyme beta)

lactamase. :onsteroidal antiinflammatory drugs :#&!s6 inhibit the acti"ity of the enyme

cycloo0ygenase choice 6, thereby decreasing the production of prostaglandins.

=ollowing e!ercise& ventilation is in e!cess of the metabolic re:uirement. ,uringthis period& the level of lactic acid in blood


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1. increases.

2. decreases.

3. remains unchanged

The correct choice is '2, decreases. #e"ere e0ercise will increase the demands on the muscle to

a point where it must rely on glycolysis for the energy. ?actic acid, as a result, will be produced.

This produces an acidotic state. &cidosis will increase "entilation, along with increasing the

number of open capillaries, to increase surface area. &n increase in the cardiac output causes an

increase in the capillary blood flow. &ll of these factors tend to decrease the concentration of the

lactic acid in the blood and return it a to its normal pre)e0ercise conditions. #o again, the

correct choice is 2.

=ollowing the birth of an infant& which of the following hormones is responsible

for increasing milk production in the mother?

&. strogen

. ?eutiniing hormone

C. -0ytocin

. Progesterone

. Prolactin

The correct answer is . Prolactin is the hormone responsible for increasing the production of

mil/ in the mammary glands of women after the birth of a child. :ote% The role of prolactin in

males is poorly understood although it is belie"ed to ha"e a role in the regulation of androgen

production. ;il/ is continuously secreted into the al"eoli of the breasts+ howe"er, it does not

flow easily from the al"eoli into the ductal system. The mil/ is inhibited from entering the ductal

system to prn," ent the continuous lea/ing of mil/ from the breasts when the mother is not

feeding. Therefore, the mil/ must be Alet downA from al"eoli to the ductal system before the

baby can obtain it. -0ytocin choice C6 stimulates the myoepithelial cells in the mammary

glands to e0press mil/ from the breast when a baby suc/les. &side from their other actions,

both estrogen choice &6 and progesterone choice 6 aid in the de"elopment of breast tissue+

howe"er, these hormones inhibit the production of mil/ in the mammary glands. ?uteiniing

ormone choice 6 plays an important role in causing o"ulation and secretion of female se0

hormones from the o"aries.

=or which of the following are the loops of -enle responsible?

1. The acidification of urine

2. The reabsorption of amino acids

3. The reabsorption of most of the glomerular filtrate

4. The formation of most of the ammonium ion e0creted in the urine

5. The establishment of an osmotic gradient within the medulla of the /idney

The correct answer is choice 5. The maor function of the loop of enle is to reabsorb sodium

ions into the cells surrounding the tubule. This absorption sets up a high concentration of solute


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which is then used to help in the passi"e reabsorption of water through the collecting tubules.

Choice 1 is incorrect. &cidification of the urine occurs by hydrogen ion secretion. This occurs

throughout all tubules of the /idney. Choices 2 and 3 are both incorrect. ;ost reabsorption, for

e0ample, of glucose and amino acids occurs in the pro0imal con"oluted tubule. @or e0ample,

more than IIH of all filtered glucose is reabsorbed in the pro0imal con"oluted tubule. Choice 4

is incorrect. *ery little ammonia is e0creted by the /idney as most is changed by the li"er to

urea. &ny ammonia in urine is the result of deamination. &s a re"iew point, remember that the

reabsorption of water is through the collecting tubules and that reabsorpuon is under the control

of & or antidiuretic hormone from the posterior pituitary. !ts action is to ma/e the collecting

tubule more permeable to water therefore more reabsorption occurs and we get a more

concentrated urine. #o the correct answer to $uestion is choice 5.

/lomerular filtration rate may be determined by clearance of

1. urea.

2. water.

3. inulin.

4. glucose.

5. para)aminohippuric acid P&6.

The correct answer is choice 3, inulin. Dlomerular filtration rate or D@( is a measure of the

"olume per time of filtrate that lea"es the glomerulus and enters the owmanEs capsule. !t is

measured by a material that is freely filtered into the owmanEs capsule and not reabsorbed nor

secreted by any tubules. !nulin, a fructose polymer, is usually used for this purpose. Choices 2

and 4 are incorrect because they are reabsorbed from the blood in the /idney tubules. Choice 5,

P& or para)aminohippurate acid, is often used to measure renal plasma flow and is a substance

freely filtered by the glomerulus but acti"ely secreted by tubular cells. Choice 1, urea, although

readily filtered into the owmanEs capsule, is more than 5H reabsorbed and readily flows into

and out of certain areas of the /idney. #o our correct answer to $uestion is choice 3.

/lycolysis begins when glucose reacts with which of the following enzymes?

&. &ldolase

. e0o/inase

C. Phosphofructo/inase

. Phosphoglucose isomerase

. Pyru"ate /inase#he correct answer is $.

Dlycolysis is defined as the se$uence of reactions that con"erts glucose into pyru"ate with the

concomitant production of &TP. The process of glycolysis begins when glucose reacts with

he0o/inase to form glucose)7)phosphate. 8hen this compound interacts with the enyme

phosphoglucose isomerase choice 6, the compound fructose)7)phosphate is formed. @ollowing

the formation of this compound, it is interacted with the enyme phosphofructo/inase choice C6

to form the compound fructose 1,7)biphosphate. 8hen interacted with aldolase choice &6

glyceraldehyde 3)phosphate is formed. &fter a number of enymatic reactions, the compound

phosphoenolpyru"ate is formed. 8hen acted upon by pyru"ate /inase choice 6, pyru"ate is

formed and the glycolytic pathway is completed.


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/lycosaminoglycans function as important structural components of

1. glycogen.

2. nucleic acids.

3. hyaluronidase.

4. connecti"e tissue

The correct answer is choice 4, connecti"e tissue. Dlycoprotein contains carbohydrate and

protein, usually more protein than carbohydrate. There is another class of glycoprotein which

contains I5H or more carbohydrate. To distinguish these compounds from other glycoproteins,

they are referred to as proteoglycans and their carbohydrate chains as glycosaminoglycans or

D&D. There are si0 classes of D&D molecules now recognied. They are made up largely of

disaccharide repeating units. oth their electrical charge and 1 molecular structure aid in their

biological role. Choice 1, glycogen, is incorrect. Dlycogen consists of alpha 1,4 or alpha 1.7)

lin/ed glucose molecules. Choice 2 is incorrect. :ucleic acids form chromatin, the material which

ma/es up chromosomes. Choice 3, hyaluronidase, is incorrect. yaluronidase functions as a

lubricant and support element in connecti"e tissue. #o the correct answer to $uestion is choice

4.

-uman parotid saliva is believed to be hyposmolar because

1. water is reabsorbed by e0cretory ducts of the gland.

2. acinar cells transport water more readily than sodium ions.

3. str

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