14146264 Physiology Last Moment Revisions Copy

8/3/2019 14146264 Physiology Last Moment Revisions Copy

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PHYSIOLOGY - Last moment revisions

Muscle PhysiologyMuscle form 40 to 50% of body mass.

About 600 muscles are identified.

Classification of Muscles:

Depending on striations: Striated(Skeletal & Cardiac) & Nonstriated(smooth)

Depending on Control: voluntary(Skeletal) & Involuntary(Cardiac & smooth)

Depending on situation: Skeletal, Cardiac & Smooth.

Muscle fiber or cell has a length b/w 1 4cm (Average 3cm) & diameter from 10

100microns.

1 myofibril contains 1500 myosin filaments & 3000 actin filaments

Sarcomere is the structural & functional unit of skeletal muscle.Length 2.5 to 3.2 mm.

Sarcomere lies b/w two Z lines

Each myofibril consists of alternate light (I or J band) & dark band (A or Q band).

Each sarcomere consist of thin (Actin) & thick (myosin) filaments.

Myosin filament is present throughout the A band.

No movement of myosin during muscular contraction.

Actin filaments are formed by 3 types of proteins called actin, tropomyosin & troponin.

The skeletal muscle is formed by 75% of water, 20% of proteins & 5%of organic

substances.

Troponin: is formed by 3 subunits; Troponin I attached to F actin; Troponin T attached

to tropomyosin; Troponin C attached to calcium ions.

Following are the muscle proteins; Myosin; Actin; Tropomyosin; Troponin; Actinin; Titin;

Desmin; Myogen & Myoglobulin.

There is no movement in the myosin filament during muscle contraction.

Actin filaments slide over the myosin filament during muscle contraction.

Tropomyosin covers the active sites of actin.

Rheobase: this is the least possible, i.e. (minimum) strength (Voltage) of stimulus which

can excite the tissue.

Chronaxie: it is the minimum time, at which a stimulus with double the rheobasic strength

(voltage) can excite the tissue.

Chronaxie of skeletal muscle is shorter than that of cardiac and smooth muscles.

Cold lengthens chronaxie. whereas vagal stimulation shortens chronaxie.


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Refractory period is the period at which the muscle does not show any response to a

stimulus.

Skeletal muscles are purely aerobic & dont have any fuel reserve.

Dark, light bands & troponin are absent in smooth muscle.

The study of electrical activity of the muscle is done by electromyography.

The muscle ruptures when it is stretched to about 3 times its equilibrium length.

Cardiovascular systemThe syncytium of called physiological syncytium because there is no anatomical

continuity of the fibers.

SA node the pace maker is a small strip of modified cardiac muscle is situated in the

superior part of lateral wall of right

atrium, just below the opening of superior vena cava.

AV node is situated in the right posterior portion of interatrial septum.

Bundle of his run on either side of the interventricular septum.

Rhythmicity of different parts of heart:o SA node : 70 to 80 / mino AV node : 40 to 60 / mino Atrial muscle : 40 to 60 / mino Ventricular muscle : 20 to 40 / min

Velocity of impulse at different parts of the conductive system.

o Atrial muscle fibres : 0.3 meter / secondo Internodal fibers : 1.0 meter / secondo AV node : 0.05 meter / secondo Bundle of his : 0.12 meter / secondo Purkinje fibers : 4 meter / secondo Ventricular muscle fibers : 0.5 meter / second

Cardiac cycle includes systole & diastole which practically includes the events of

ventricles.

When heart beats at the normal rate of 72/min, the duration of cardiac cycle is 0.8sec.

The duration ofsystole is 0.27 sec & that ofdiastole is 0.53 sec.

The subdivision with duration areo Systole

Isometric contraction = 0.05 sec


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Ejection period = 0.22 seco Diastole

Protodiastole = 0.04 sec Isometric relaxation = 0.08 sec Rapid filling = 0.11 sec Slow filling = 0.19 sec Atrial systole = 0.11 sec Total duration of cardiac cycle = 0.27 + 0.53 = 0.8 sec.

Atrial systole: atrial contract & a small amount of blood enter the ventricles.

Isometric contraction: all the valves are closed, ventricles undergo isometric

contraction & pressure in the ventriclesis increased.

Ejection period: semilunar valves opened, ventricles contract & blood is ejected out.

Protodiastole: this is the first diastole. The semilunar valves are closed at the end of

this period.

Isometric relaxation: all the valves are closed, ventricles undergo isometric

relaxation & pressure in the ventricles is reduced.

Rapid & slow filling: Atrioventricular valves are opened, ventricles relax & filling

occurs.

Pressure difference

Pressure RightAtrium

Left

AtriumRight

VentricleLeft

VentricleSystemic

AortaPulmonary

arteryMax(mm of

Hg)5 6 7 8 25 120 120 25

Min(mm of

Hg)0 2 0 2 2 3 5 80 7 8

End systolic volume is 70 90 ml End diastolic volume is 130 150 ml.


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Q T

interval

Onset of Q

wave &

end of T

wave

Electrical activity in

ventricles.

0.4 0.42-

ST

segment

End of S

wave &

onset of T

wave-

0.08-

In hyperkalemia, ECG shows a tall T wave.

In hypokalemia, ECG shows depressed S-T segment. Heart sounds.

Heart

sounds

Occurs

during

Cause Characteristics Duration(sec)

Relation

to ECG

First Isometriccontraction

& ejection

period

Closure of

AV valvesLong, soft, &

low pitched.

Resembles the

word LUBB

0.10

0.17R wave

Second Protodiastole& part of

isometric

relaxation

Closure of

semilunar

valves

Short, sharp,

& high pitched.

Resembles the

word DUBB

0.10

014Precedes

or

appears

0.09 sec

after

summit

of T

waveThird Rapid filling Rushing of

blood into

ventricles

Low pitched 0.07 0.1

B/W P

wave &

Q

wave.Fourth Atrial systole Contraction

of atrial

musculature

Inaudible

sound

0.02

0.04B/W P

wave &

Q wave Bradycardia: decrease in rate below 60 / min.


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Arrhythmia: irregular heart beat.

Sinus tachycardia: increase in discharge of impulse from SA node, upto 100 /

min Sinus bradycardia: reduction in the impulses from SA node, about 40 / min Atrial flutter: Atrial rate is about 250 350 / min Atrial fibrillation: rate of 300 400 beats / min Ventricular fibrillation: rate is about 400 500 / min Bain Bridge reflex (venous reflex) is characterized by reflex increase in Heart

rate on venous engorgement of the

right atrium.

Mary's law states that the Heart rate and Blood pressure have inverse

relationship. Stokes Adams syndrome is characterized by repeated fainting attacks

associated with complete heart block. Cardiac Output:

o The amount of blood pumped from each ventricle.

Stroke volume:the amount of blood pumped out by each ventricle during each beat -

70ml.

o Stroke volume at rest is 80 - 100 ml. Minute volume:amount of blood pumped out by each ventricle in one minute. Minute

volume = stroke volume X heart

rate. 5 liters/per ventricle/minute.

Cardiac Index: the minute volume from ventricle expressed in relation to square

meter of body surface area. Normalvalue: 2.8 0.3 liters / 1 square meter of body surface area / minute.

Ejection fraction: the fraction of end diastolic volume that is ejected out by each

ventricle. Normal 60 to 65%.

Cardiac reserve: the maximum amount of blood that can be pumped out by the heart

above normal value. Normal

healthy adult: 300 400%. Variations in Cardiac output: (Physiological)

o Less in children, females, early morning, changing from recumbent to upright

position & in sleep.

o Increased in males, greater body build, day time, emotional upset, after

meals, after exercise, high attitude,


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and later months of pregnancy.

Distribution of Cardiac output:

Organ Amount of blood PercentageLiver 1500ml 30%Kidney 1300ml 26%Skeletal muscles 900ml 18%Brain 800ml 16%Skin, bone & GIT 300ml 6%Heart 200ml 4%Total 5000ml 100%

Factors maintaining Cardiac output:

1. Venous return Respiratory pump; Muscle pump; Gravity; Venous pressure; Vasomotor

tone.

2. Force of contraction3. Heart rate4. Peripheral resistance

Regulation of Heart rate:

1. Vasomotor center: bilaterally situated in the reticular formation of medulla

oblongata & lower part of pons.2. Motor nerve fiber of heart.

3. sensory nerve fiber Haemodynamics:

Factors maintaining volume of flow of blood. Pressure gradient; Resistance to blood flow; Viscosity of blood; Diameter of

blood vessels; Velocity of blood flow: Arterial Blood pressure:

Systolic pressure: maximum pressure exerted in the arteries during the systole of

heart. Normal: 120 mmHg.

(range 110 140) Diastolic Blood Pressure: minimum pressure in the arteries during the diastole of

the heart. Normal: 80 mmHg(range 60 90) Pulse pressure: Difference between the systolic pressure & diastolic pressure.

Normal: 40 mmHg.


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Mean arterial blood pressure: this is the diastolic pressure plus one-third of

pulse pressure. Normal: 93 mmHg.

Variations (Physiological)o Lessin children, females before menopause, early morning & in sleep.

o Increased in males, greater body build, and day time, after meals, after

exercise, sleep with dreams.

Determinants of Arterial blood pressure:

Cardiac output; Heart rate; Peripheral resistance; Venous return; Elasticity &

Diameter of blood vessels; Velocity of blood flow; Viscosity of blood Regulation of Arterial blood pressure:

o Nervous mechanism: by vasomotor center & impulse from peripheryo Renal mechanism: by regulation of ECF volume & rennin-angiotensin

mechanism.o Localmechanism

Local vasoconstrictors & Local vasodilatorso Hormonalmechanism:

Hormones increase BP Hormones decrease BPAdrenalineNoradrenalineThyroxineAldosteroneVasopressinAngiotensinSerotonin

Vasoactive intestinal

polypeptide(VIP)BradykininProstaglandinHistamineAcetylcholineAtrial natriuretic peptide

Venous pressure:

o Venous pressure in Jugular vein: 5.1 mmHg (6.9 cm H2O)o Venous pressure in superior vena cava: 4.6 mmHg (6.2 cm H2O)o Portal venous pressure: 10 mm Hgo Hepatic venous pressure: 5 mm Hg.

Capillary pressure:o Capillary pressure in the arterial end is about 30 32 mmHg & venous end is

about 15 mmHg.

o It is high in Kidney (glomerular capillary pressure), about 60 mmHg

responsible for filtration.o Low in lungs (pulmonary capillary pressure), about 7 mmHg.


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Venous pulse: (it is the pressure changes transmitted in the form of waves from

right atrium to the veins near the heart)

o Recording of JVP is called phlebogram.o Phlebogram has 3 positive waves a, c & v and 3 negative waves x, x1 & y.

o awave 1st

positive wave & its due to atrial systole.

o xwave fall of pressure in atrium, coincides with atrial diastoleo cwave its due to rise in atrial pressure during isometric contraction during

which the AV valves bulges into atrium.

o x1 wave occurs during ejection period, when AV ring is pulled towards

ventricles causing distension of atria.

o vwave occurs during isometric relaxation period or during atrial diastole.o ywave due to opening of AV valve & emptying of blood into ventricle.

Nervous system Neuron is defined as the structural & functional unit of nervous system.

Neuron does not have Centrosome so it cannot undergo division.

Nissl bodies are organelles containing ribosomes & are concerned with synthesis of

protein in neurons.

Dendrites are conductive in nature & transmit impulses towards the nerve cell body.

Axons are longer process of the nerve cell concerned with transmission of impulse

away from the nerve cell body.

The myelin sheath envelops the axon except at its ending and at the nodes of

Raniver.

Myelin sheath is responsible for faster conduction of impulse through the nerve fiber

& also acts as an insulating material.

Neurotrophins are the substances, which facilitate the growth, survival & repair of

the nerve cells.

A alpha (Type Ia) nerve fiber is said to be the fastest nerve with a velocity of

conduction of 70 to 120 meters / second.

Glial cells are very abundant and as many as 10 to 50 times as neurons. Astrocytes form supporting network in brain & spinal cord, form basis for blood brain

barrier.

Microglia is phagocytic in function.

Oligodendrocytes are responsible for the formation of myelin sheath in CNS

because schwann cells are absent there.

Receptors:


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o Exteroceptors: give response to stimuli arising from outside the body.

(Cutaneous, Chemoreceptors & Telereceptors)o Interoceptors: give response to stimuli arising from within the body.o Cutaneous receptors: Touchreceptors: Meissners corpuscle & Merkels disc (max in lips & fingers)

Pressure receptors: Pacinian corpuscles Temperature receptor

o Cold: Krauses end organo Warm: Raffinis end organo Warm receptors respond at body temperature of 30 - 45C.

o Cold receptors are activated at body temperature of 10C or below.

o Warm Sensation is carried by C Fibres.

o Cold Sensation is carried by A. & C fibres. Pain receptors: free (naked) nerve ending. (sensation which return earliest

on recovery)o Chemoreceptors:

Taste: Taste buds Smell: Olfactory receptors Hearing: hairs cells of organ of corti in the internal ear.

Vision: Rods & Cones in retina for visual sensation.

o Viseroreceptors: Stretch receptors, baroreceptors, chemoreceptors & Osmoreceptors

o Proprioceptors: give response to change in position labyrinthine, muscle

spindle, golgi tendon, pacinian

corpuscle, muscle, tendon & fascia.

Neurotransmitters:o Excitatoryneurotransmitter: is responsible for the conduction of impulse from

the presynaptic neuron to thepostsynaptic neuron.

o Inhibitory neurotransmitters: inhibits the conduction of impulse from thepresynaptic neuron to the postsynaptic neuron.

Group Name Action

Amino acidsGABA InhibitoryGlycine InhibitoryGlutamate Excitatory


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Aspartate Excitatory

Amines

Adrenaline Inhibitory & ExcitatoryNoradrenaline Inhibitory & ExcitatoryDopamine InhibitorySerotonin InhibitoryHistamine Excitatory

Others Nitric oxide ExcitatoryAcetylcholine Excitatory

Superficial reflexes:Reflex Stimulus Response CenterCorneal Irritation of cornea Blinking of eye PonsConjunctival Irritation of

conjuctivaBlinking of eye Pons

Nasal Irritation of nasalmucus membrane

Sneezing Motornucleus of V

cranial nervePharyngeal Irritation of

pharyngeal mucus

membrane

Retching of

gaggingNuclei of X

cranial nerve

Uvular Irritation of Uvula Raising of Uvula Nuclei of Xcranial nerve

Superficial cutaneous reflexesReflex Stimulus Response Center

spinal

segment

involved

ScapularIrritation of skin at the

interscapular spaceContraction of

scapular muscles &

drawing in of

scapulaC5 to T1

Upper

abdominal

Stroking the

abdominal wall below

the costal margin

Ipsilateral

contraction of

abdominal muscle &

movement of

T6 to T9


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umbilicus towards

the site of stroke

Lower

abdominal

Stroking the

abdominal wall at

umbilical & iliac level

Ipsilateral

contraction of

abdominal muscle &

movement of

umbilicus towards

the site of stroke

T10 to T12

CremastericStroking the skin at

upper & inner aspect

of thigh

Elevation of testiclesL1, L2

Gluteal Stroking the skin overglutei

Contraction of glutei L4 to S1,

S2

Plantar Stroking the sole Plantar flexion &adduction of toes L5 to S2

Bulbocavernous Stroking the dorsumof glans penis

Contraction of

bulbocavernous S3, S4

AnalStroking the perianal

regionContraction of anal

sphincter S4, S5 Deep reflexes

Reflex Stimulus Response Center spinal

segment

involved

Jaw jerkTapping middle of the

chin with slightly opened

mouth

Closure of mouth Pons Vcranial

nerveBiceps jerk Percussion of biceps

tendonFlexion of forearm

C5, C6

Triceps jerk Percussion of tricepstendon

Extension of

forearm C6 to C8Supinator jerk

or radial

periosteal

Percussion of tendon

over distal end (Styloid

process) of radius

Supination &

flexion of forearm C7, C8


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reflexWrist tendon or

finger flexion

reflex

Percussion of wrist

tendonsFlexion of

corresponding

fingerC8, T1

Knee jerk or

Patellar tendon

reflexPercussion of patellar

ligamentExtension of leg

L2 to L4

Ankle jerk or

Achilles tendon

reflex

Percussion of Achilles

tendonPlantar flexion of

foot L5 to S2

Pathological reflexes:

Babinskis sign: there is dorsiflexion of great toe & fanning of other toes. Seen in

UMN lesion, also in infants &

normal persons with deep sleep.

Spinal cord:Extends from foramen magnum to 1st lumbar vertebra.

Length 45 cm in male & 43 cm in females.

Below the lumbar enlargement, the spinal cord rapidly narrows to a cone shaped

termination called Conus medullaris.

Spinal corresponds to 31 pairs ofspinal nerves. (C-8; T-12; L-5; S-5; C-1)Grey matteris the collection of nerve cell bodies, dendrites & parts of axons.

White matteris a collection of myelinated & nonmyelinated nerve fibers.

Neurons in the grey matter of spinal cordNeurons in Anterior gray horn

Alpha motor neurons; Gamma motor neurons & Renshaw cellsNeurons in lateral gray horn

Intermediolateral horn cellsNeurons in posterior gray horn

Substania gelatinosa of Rolando; Marginal cells; Chief sensory cells &

Clarkes column of cells.

Ascending tracts of Spinal cord:

Situation Tract FunctionAnterior white

funiculus Anterior spinothalamic tract Crude touch sensation


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Lateral white

funiculus

Lateral spinothalamic tract Pain & temperature sensationVentral spino cerebellar tract Subconscious kinesthetic

sensationsDorsal spino cerebellar tract

Subconscious kinesthetic

sensationsSpinotectal tract Concerned with spinovisual reflexFasiculus dorsolateralis Pain & temperature sensationsSpinoreticular tract Conciousness & awarenessSpinoolivary tract ProprioceptionSpinovestibular tract Proprioception

Posteriorwhite

funiculus

Fasciculus gracilis Tactile sensationTactile localizationTactile discriminationVibratory sensationConscious kinesthetic sensationstereognosis

Fasciculus cuneatus

Descending tracts of Spinal cord:

Situation Tract FunctionPyramidal

tracts

Anterior corticospinal

tract Control voluntary movementsForms upper motor neuronsLateral corticospinal

tract

Extra

Pyramidal

tracts

Medial longitudinal

fasciculusCoordination of reflex ocular movement

Integration of movements of eyes & neckAnterior vestibulospinal

tract

Maintenance of muscle tone & postureMaintenance of position of head & body

during accelerationLateral vestibulospinaltract

Reticulospinal tract

Coordination of voluntary & reflex

movements.Control of muscle tone.Control of respiration & blood vessels.

Tectospinal tract Control of movement of head in response tovisual & auditory impulses.

Rubrospinal tract Facilitatory influence on flexor muscle tone.


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Olivospinal tract Control of movements due to proprioception.Effect of upper motor neuron & lower motor neuron lesion:

Effects upper motor neuron lowermotorneuronlesion

Clinical

observation

Muscle tone Hypertonic HypotonicParalysis Spastic type of paralysis Flaccid type

of paralysisWastage of muscle No wastage PresentSuperficial reflexes Lost LostPlantar reflex Abnormal babinskis

sign AbsentDeep reflexes Exaggerated LostClonus Present Lost

Clinical

confirmation

Electrical activity Normal AbsentMuscles affected

Groups of muscles areaffected Individualmuscles are

affectedFascicular twitch in

EMGAbsent present

Action of sympathetic & parasympathetic divisions of ANS:Effector organ Sympathetic division Parasympathetic

divisionEye Ciliary muscle Relaxation Contraction

Pupil Dilatation ConstrictionLachrymal secretion Decrease Increase

Salivary secretionDecrease in secretion &

vasoconstrictionIncrease in

secretion &

vasoconstriction

GITMotility Inhibition AccelerationSecretion Decrease Increasesphincters constriction Relaxation

Gall bladder Relaxation contractionUrinary bladder Detrusor muscle Relaxation contraction

Internal sphincter Constriction RelaxationSweat glands Increase in secretion -Heart rate & force Increase decreaseBlood vessels Constriction of all blood Dilatation


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vessels except those in

heart & skeletal muscleBronchioles Dilatation Constriction

Resting membrane potential of various cells of the body.

Resting membrane potential of a skeletal muscle is -90mV.

Resting membrane potential of a smooth muscle is -50 to -75mV.

Resting membrane potential of a cardiac muscle is -85 to -95mV.

The resting membrane potential in the nerve fiber is -70mV.

The resting membrane potential in the rods is -40mV.

The resting membrane potential of inner ear cell is -60mV.

Brain stem: (medulla oblongata, Pons & Midbrain)Pathway for ascending & descending tracts b/w brain & spinal cord.

Important centers for regulation of vital functions in body.

Medulla oblongataRespiratory centers: inspiratory & expiratory.

Vasomotor center: B.P & Heart rate.

Deglutition center: Pharyngeal & Oesophageal stage.

Vomiting center: induce vomiting.

Superior & inferior salivatory nuclei: controls secretion of saliva.

Cranial nerve nuclei: nuclei of 10, 11 & 12 cranial nerves.

Vestibular nuclei:Pons

Bridge b/w medulla & midbrain.

Forms pathway connecting cerebellum with cortex.

Nuclei of 5 to 8th cranial nerve.

Pneumotoxic & apneustic centers for regulation of respiration.

Midbrain: (Consist of 2 parts Tectum & cerebral peduncles)Tectum: center for light & auditory reflexes.

Cerebral peduncles: control of muscle tone Control of complex & skilled muscular movements, movement of eye ballsThalamus: Ovoid mass of gray matter, situated B/L in diencephalons)

Relay center: for sensations (also called functional gateway).Center for integration of sensory impulses: determining the quality of

sensations(discriminative & affective nature)Center for sexual sensations.


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Role in arousal & alertness reactions.

Center for reflex activity

Center for integration of motor functions.

Hypothalamus:Control the secretion of Ant. & Post Pituitary hormones & adrenal cortex & medulla.

Control of Autonomic nervous system; Heart rate; B.P; Body temp; Food intake

(satiety, hunger &thirst); water balance; sleep & wakefulness.

Role in behaviour & emotional changes.

Regulation of sexual function & response to smell.

Role in circadian rhythm.

Cerebellum:Vestibulocerebellum: regulates tone, posture & receiving impulse for vestibular

apparatus.

Spinoncerebellum: regulates tone, posture & equilibrium by receiving impulses from

proprioceptors in muscles, tendons

& joints, tactile receptors, visual receptors & auditory receptors.

Corticocerebellum: concerned with the integration & regulation of well coordinated

muscular activities.

Different parts are represented in an upright manner in cerebellum. (opp: in cerebrum)Basal ganglia: (concerned with motor activities of extra-pyramidal system)

Control of voluntary motor activity, muscle tone, reflex muscular activity, associated

movements.

Role in arousal mechanism.

Cerebral cortex:

Frontal

lobe

Pre

central

cortex

(Post.

Part)

Primary motor area(concerned with

initiation of voluntary

movements & speech)

Area 4 center for movementArea 4S suppressor area.

Inhibits movements initiated by

area 4.

Pre motor areaArea 6 concerned with

coordination of movements

initiated by area 4.

Area 8 frontal eye field.

Area 44 & 45(brocas area)motor area for speech.

Supplementarymotor area Concerned with co-ordinatedskilled movements.

Pre Silent area or Area 9 to 14, 23, 24, 29 &


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frontal

cortex

(Ant.

Part)

association area

Center for higher

functions emotion,learning, memory.

32. Center for planned action.

Seat of intelligence. Personality

of individual.

Parietal

lobe

Somesthetic area I

Area 1 concerned with

sensory perceptionArea 2 & 3 integration ofthese sensations. Spatial

recognition. Recognition of

intensity, similarities & diff. B/Wstimuli

Somesthetic area II Concerned with perception ofsensation.

Somesthetic association area Synthesis of various sensationsperceived by S.Area-I.Stereognosis.

Temporal

lobe

Primary auditory area Area 41, 42 & wernickesarea concerned with

perception of auditory impulses,

analysis of pitch, determination

of intensity & source of soundAuditopsychic area Area 22 interpretation of

auditory sensationArea of equilibrium Maintenance of equilibrium

Occipital

lobe

Primary visual area Area 17 perception of visualimpulse

Visual association area Area 18 - Interpretation ofvisual impulses

Occipital eye field Area 19 - Movements of eye

Limbic system: (It is a group of cortical & sub cortical structures which form a ring around

the hilus of cerebral hemisphere)Regulation of olfaction, autonomic functions (B.P, water balance & body temp).Control of circadian rhythm.

Regulation of sexual function.

Role in emotional state, memory & motivation.

Retention of recent memory.

Most developed part of Limbic System Hippocampal formationMajor efferent from Limbic system goes to Mid brain reticular formation.Main function of Limbic system is to Control the emotional behaviour.


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Proprioceptors: (These are receptors which give response to change in the position of

different parts of the body).

Muscle spindle: gives response to change in length of muscle.

Golgi tendon organ: gives response to change in force developed in muscle.

Pacinian corpuscle: pressure receptor in fascia, tendon & joints.

Free nerve endings:

Vestibular apparatus:Give response to rotatory movements or angular acceleration of the head.

Responsible for detecting the position of head during different movements.

EEG: (ELECTROENCEPHOLEGRAM)

Alpha rhythm:

Frequency: 8 to 12 waves / secAmplitude: 50U.

Most marked in parieto-occipital area.

Obtained in inattentive brain as in drowsiness & light sleep.

Beta rhythm:

Frequency: 15 to 60 waves / secAmplitude: 5 - 10U.

Recorded during mental activity or mental tension or arousal state.

Delta rhythm:

Frequency: 1 to 5 waves / secAmplitude: 20 - 200U.

Seen in tumour, epilepsy, increased intracranial pressure & mental depression.

Theta rhythm:

Frequency: 4 to 8 waves / secAmplitude: 10U.

Seen in children below 5 years.

SLEEP:

Sleep requirement:

Newborn infants: 18 to 20 hours.Growing children: 12 to 14 hours.Adults: 7 to 9 hours.Old persons: 5 to 7 hours.

Types of sleep:Rapid eye movement sleep(REM) Non rapid eye movement

sleep(NREM)


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Eye balls move AbsentDreams occur AbsentMuscle twitching Absent20 to 30% of sleep 70 to 80% of sleep

Normal amount of C.S.F. in man is 150 C.C,

Sympathetic nervous system is controlled by Posterior hypothalamic nucleiParasympathetic nervous system is controlled by Anterior nuclei and part of middle

nuclei of hypothalamus.EYE:

Refractory poweris measured in dioptre (D).

Refractory power of cornea is 42D.

Refractory power of lens is 23D.

Refractory power of eye at rest is 59D.

Focal length of cornea is 24mm.

Focal length of lens is 44mm.

The wave lengths of visible light are approximately 397 to 723 nm.There are about 6 million cones & 12 million rods in human eye.

Rods are responsible for dim light or night vision or scotopic vision.

Cones are responsible for colour vision, sensitive to day light & acuity of vision.

Rhodopsin is the photosensitive pigment of rods cells.

Photosensitive pigment in cones are

o Porpyropsin Redo Iodopsin Greeno Cyanopsin Blue

Electroretinogram is the instrument to record the electrical basis of visual process.

Test for visual acuitysnells chart (distant vision) & Jaegers chart (near vision).

Test for color blindness Ishiharas colour chart. Mapping of visual field perimetry.

Nearest pointat which the object is seen clearly is about 7 to 40cm.

Farthest pointis infinite.

Myopia (short sightedness) is corrected by concave lens.

Hypermetropia (long sightedness) is corrected by convex lens.

Astigmatism is corrected by cylindrical lens.

Presbyopia is corrected by convex lens.

EAR:


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Ear is sensitive to sound between 1000 to 4000Hz range.

Hairs cells in organ of corti are the receptors for auditory sensation.

Sound becomes painful above 140db.

Auditory centers 41, 42 & also auditopsychic area 22.

TONGUE: Sense organ of taste sensation is taste buds.

There are about 10,000 taste buds & each taste bud is replaced in every 10 days.

Each taste bud consists of 4 types of cells and is supplied by about 50 nerve fibres. Receptors are type III cells of taste buds.

Taste center opercular insular cortex (lower part of post central gyrus).

Bitter taste has very low threshold 1 in 2,000,000.

Sweet taste has high threshold 1 in 200.

Locations of taste buds are: sweet tip; salt dorsum; sour side; bitter

posterior.

SMELL: Olfactory mucus consists of 10 to 20 million olfactory receptor cells.

Human nose can distinguish 2000 to 4000 different odours.

GASTRO INTESTINAL SYSTEM GIT is a tubular structures extending from the mouth up to anus with a length of

about 30 feet.

A normal healthy adult consumes about 1kg solid diet & about 1 2 liters of liquiddiet / day.

Auerbachs plexus regulate the movements of GIT. Meissners plexus regulate the secretory functions of GIT. Auerbachs plexus is present between the middle circular muscle layer & outer

longitudinal muscle layer & its major function is to regulate the movements of GIT.

The total volume of GIT secretions per day is about 8000 ml. Properties & composition ofSaliva:

Volume: 1000 1500 ml / day, (70% by submaxillary glands). Reaction: pH 6.35 6.85.

Specific gravity: 1.0002 1.012 Composition: 99.5% water & 0.5% solids.

Digestive enzymes: salivary amylase (carbohydrate splitting) & lingual

lipase (lipid splitting enzyme).


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Substances like mercury, potassium iodide, lead & thiocyanate are excreted

through saliva.

Saliva contains highest conc. of K+.

Volume of stomach is 50 ml when empty & can expand up to 4 liters.

Properties & composition ofgastric juice: Volume: 1200 1500 ml / day.

Reaction: pH 0.9 1.2.


Digestive enzymes: Pepsin, Gastric lipase & other gastric enzymes.

Action ofpepsin: attacks peptide bonds adjacent to aromatic amino acids by

hydrolysis.

Action ofgastric lipase: weak lipolytic enzyme becomes active only when pH is

between 4 & 5.

Action ofHCL: activates pepsinogen into pepsin, bacteriolytic action, causes

acidity of the chime & provides acid medium for the action of enzyme.

Gastrin is one of the GIT hormones secreted by G cells present in pyloric glands

of stomach.

Action of Gastrin: stimulates the secretion of pepsinogen & Hcl by gastric glands,

increases the motility of stomach, secretion of pancreatic juice & production of

hormones by pancreas.

Pancreas is a dual organ & has endocrine & exocrine function.

Properties & composition ofPancreatic Juice: Volume: 500 800 ml / day.

Reaction: pH 8 8.3.


An adult pancreas has 2.5-7.5 lac islets. Total volume of pancreatic secretion per day is 2.5 liters. Pancreas is the only organ that contains Trypsinogen.

Ascariasis can also cause acute pancreatitis. Serum amylase and lipase levels are usually not elevated in chronic

pancreatitis. Duodenum is the principal site ofiron absorption.


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Most sensitive method for assessing pancreatic exocrine function is Secretin

Stimulation Test. Blood flow reaching the liver via portal versus hepatic artery is 4: 1. Hepatic venous pressure is 5mm Hg. Most common complaints resulting from disorders involving the GIT include pain and

alteration in bowel habit. Most potent stimulus for bile secretion is bile salt. Best stimulus for CCK secretion is Fat. Properties ofBile:

o Volume: 800 1200 ml / dayo Reaction: alkalineo pH: 8 8.6o Sp. Gty: 1010 - 1011

Composition of Bile:o Water: 97.6%o Solids: 2.4%

Bile is stored in gall bladder; it undergoes many changes in quality & quantity. There is increase in conc. of bile salts, bile pigments, cholesterol, fatty acids &

lecithin.

Functions ofbile salts:o Emulsification of fats, due to emulsification, fat globules are broken down into

minute particles.

o Absorption of fats.o Stimulate the secretion of bile from liver.o Prevention of gall stone formation.

Properties ofsuccus entericus:o Volume: 1800 ml / dayo Reaction: alkalineo pH: 8 8.3o

Sp. Gty: 1010 - 1011 Enzymes of succus entericus:

o Proteolytic enzymes: peptidases amino peptidases, dipeptidase &tripeptidase.

o Amylolytic enzymes: sucrase, maltase, isomaltase, lactase, dextrase &trehalase.


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o Lipase & enterokinase Bacterial flora of large intestine synthesizes folic acid, Vit B12 & Vit K. Vomiting center is situated bilaterally in medulla oblongata near the nucleus

tractus solitarius.

Segmentation contraction & pendular movement are involved in mixing of food insmall intestine.

Peristaltic movements peristaltic rush are the two movements involved in thepushing of chyme towards aboral end on intestine.

Desire for defecation is elicited by an increase in the intrarectal pressure to about20 to 25 cm H2O.

Gastrointestinal hormones:Hormone Source of

secretionActions

Gastrin G cells ofstomach;

duodenum,

jejunum, Ant. Pit &

Brain

1. Stimulates the secretion of gastric

juice.2. Increase the gastric motility.

Stimulates the release of pancreatic

hormones.

Secretin S cells ofduodenum,

jejunum & ileum

Stimulates secretion of watery,

alkaline & pancreatic secretions.

Cholecytokinin I cells induodenum,

jejunum & ileum

Stimulates contraction of gall bladder;

Activates secretin; Inhibits gastric

motility; Increases secretion of

enterokinase & intestinal motility.

Gastric

inhibitory

peptide (GIP)

K cells in

duodenum &

jejunum

Inhibits secretion of gastric juice,

gastric motility & increase insulin

secretion.

Digestion of Carbohydrates:Area Juice Enzyme Substrate End ProductMouth Saliva Salivary amylase Polysaccharides DisaccharidesStomach Gastric

juiceGastric amylase Weak amylase The action is

negligibleSmall Pancreatic Pancreatic Polysaccharides Disaccharides


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intestine juice amylase Disaccharides dextrins, maltose &maltrioseMonosaccharides

Succus

entericus

SucraseMaltase

LactaseDextrinaseTrehalase

Disaccharides Glucose

Skin

Skin is the largest organ in the human body. The normal body temperature varies is between 35.8 37.30. Axillary temperature is slightly lower, while rectal temp. is slightly higher. Heat lose center is situated in pre-optic nucleus of ant. Hypo thalamus. Heat gain center is situated in post. Hypothalamic nucleus. Primary motor center for shivering is situated in post. Hypothalamus, near the wall

3rd ventricle.

RESPIRATORY SYSTEM The major phospholipids present in the surfactant are di-palmitoylphosphatidyl

choline.

Surfactant is secreted by type II alveolar epithelial cells. Total peripheral resistance falls about 50% in moderate exercise. Cyanosis is detectable when arterial oxygen saturation falls below 75%

corresponding to PO2 of 40 mmHg.

250ml of oxygen enters the body per min and 200 ml of CO2 is excreted. 5 ml of 02 is transported to the tissues by 100 ml blood in every cycle Pulmonary alveolar macrophages form called "Dust cells". Size and strength of respiratory muscles is 30-40% above normal in athletes

whereas it is 20-30% less in physically weak people. There are about 300 million alveoli in man. There is no stimulation of ventilation by hypoxia until the alveolar O2 falls below 60

mm Hg. Oxygen transported from lung to tissues in chemical combination is 97%. In a healthy adult, 24 hour production of CO2 is about 330 liters. Diffusion capacity for carbon dioxide as compared to that of 02 is 20 times.


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Average area of the alveolar walls in contact with capillaries in both lungs is about70 sq. m.

Diffusion capacity of lungs for CO2 is 10-30 ml/min/mmHg. Normal composition of venous blood is PO2 - 40 mmHg, PCO2 -46 mm Hg and Hb

saturation 75%. Peak expiratory flow rate is 400-500 L/mt. The presence of Hb increases the 02 carrying capacity of the blood by 70 fold. Intra-pleural pressure (recoil pressure) required to prevent collapse of the lung

4 mm Hg in presence of surfactant. Intrapleural pressure at the end of deep inspiration is - 4 mm Hg. Intrapleural pressure during expiration is - 2 mm Hg. Compliance of the normal lungs and thorax combined 0.13 liter/cm, of H2O. Compliance of the normal lungs alone is 0.22 liter/cm of H2O. During normal quiet breathing only 2-3% of the total energy expenditure is needed

for pulmonary ventilation. The amount of alveolar air replaced by new atmospheric air with each breath is only

l/7th. Expired air contains 2/3rdalveolar air + l/3rddead space air. 63% of carbon dioxide is transported as bicarbonate form 97% of O2 is transported by Hb, rest 3% is in dissolved state in the water of the

plasma and cells. Carbon mono oxide binds with Hb. 230 times more strongly than ()2. Under resting conditions each 100 ml of blood transports 5 ml of O2to tissues and

carries 4 ml of CO2 from tissues to the lungs. Death occurs usually when the pH of the blood falls to 6.9. The decrease in 02 affinity of Hb when the pH of blood falls is called Bohrs effect. The degree of stimulation ofchemoreceptors depends on arterial PO2. Spirometer cannotmeasure Functional Residual Capacity. Functional residual capacity is measured by Nitrogen wash out or single breath

oxygen method.

Most potent respiratory stimulant is carbon dioxide. Kausmaul breathing is seen in diabetic ketoacidosis and it is not a feature of

Hypercapnic acidosis. Hering-breuer reflex: impulses from stretch receptors. Peripheral chemoreceptors are carotid & aortic bodies.


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Respiratory centers:o Inspiration dorsal group of neurons near tractus solitarius nucleus.o Expiration ventral group situated in ventral part of medulla.

Normal value of FEV 1 in an adult male is 80%. Muscles of InspirationDiaphragmand External Intercostals muscle (Others -

Stcrnocleidomastoid, Serratus anterior).

Muscle of ExpirationInternal Intercostal muscle. (Rectus abdominis). Intra alveolar pressure during inspiration 1 mm Hg. Tidal volume: 500 ml. Inspiratory reserve volume: 3300 ml. Expiratory reserve volume: 1000 ml. Residual volume: 1200 ml. Respiratory minute Volume in a normal person is 6.0 L/min. Inspiratory capacity: 3800 ml. Vital capacity : 4800 ml. Total lung capacity: 6000 ml. Functional residual capacity in a male is 2.2 liters. Normal dead space air volume 150 ml. Timed vital capacity in 1sec is 83%. Timed vital capacity in 2 sec is 94%. Oxygen dissociation curve is S shape or sigmoid shape.

Shift to right Shift to leftDecrease pH Increase pHIncrease in temp decrease in tempExcess of 2, 3 DPG Foetal bloodIncrease PCO2 (Bohr effect) -Decrease PO2 -

ENDOCRINE SYSTEM Hormone which acts on the target cell is called as 1st messenger. Cyclic AMP is the most common 2nd messenger for protein hormones. Other 2nd messengers are Ca++, Calmoduline, Inositol triphosphate(IP3) & cyclic

GMP.

Anterior pituitary hormones areo Growth hormone or somatotropic hormone


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o Thyroid stimulating hormoneo Adenocorticotropic hormoneo Follicle stimulating hormoneo Luiteinizing Hormone or interstitial cell stimulating hormones in maleso Prolactin.

Posterior pituitary hormones areo Antidiuretic hormone or vasopressino Oxytocin

ADH causes conservation of body water & contraction of vascular smooth muscle. Gigantism is due to the hyper secretion of growth hormone in childhood or in the

pre-adult life before the fusion of epiphysis of bone with the shaft.

Acromegaly is due to hyper secretion of GH in adults after the fusion of epiphysiswith shaft of the bone.

Dwarfism is a disorder of GH reduction in infancy or early childhood. Diabetes insipidus is a syndrome developed due the defiency of ADH. Hormone responsible for uterine contraction during labour & letting down of milk is

Oxytocin. The anterior pituitary has the largest blood flow of any tissue in the body. Anterior pituitary hormones with diabetogenic effect GH, ACTH, TSH, and PRL. Pigmentation is not a feature of panhypopituitarism. Hormones of thyroid gland are

o Thyroxine (T4) 90%o Triiodothyronine (T3) 10%o Calcitonin

Potency of T3 is four times more than that of T4. Graves disease is an auto-immune disease which causes

hyperthyroidism.(exophathalmic goiter)

Cretinism is hypothyroidism in children & myxedema due to hypothyroidism inadults.

Parathormone is secreted by para thyroid gland & its main function is to increasethe blood Ca++ level by mobilizing Ca++ from bone.

Calcitonin reduces the blood Ca++ level by decreasing the bone re-absorption. Tetany results from hypocalcaemia, caused by hypoparathyroidism. Pancreatic hormones are

o Alpha cell Glucagons


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o Beta cells Insulino Delta cells Somatostatino F or PP cells Pancreatic polypeptide

Insulin is the only anti diabetic hormone secreted in the body. Glucagons actions are antagonistic to that of insulin. Somatostatin inhibits the secretion of both glucagons & Insulin. Hormones of Adrenal cortex are

o Mineralocorticoids (secreted by zona glomerulosa) Aldosterone ( Na+ & excretion of K+) 11 deoxy corticosterone

o Glucocorticoids (zona fasiculata) Cortisol Corticosterone

o Sex hormones (zona reticularis) Dehydroepiandrosterone Androstenedione Testosterone

Cushing syndrome is a disorder characterized by obesity due to hyper secretion ofglucocorticoids.

Conns syndrome is primary aldosteronism. Addisons disease is chronic adrenal insuffiency. Hormones of Adrenal medulla (Catecholamines) are

o Adrenaline or epinephrineo Noradrenaline or norepinephrineo Dopamine

Pheochromocytoma is a condition in which there is excessive secretion ofcatecholamines.

Melatonin is secreted by parachymal cells of pineal gland, acts on gonads.

Severe stress can raise ACTH and cortisol level by 20 folds. Fetal lung maturation depends on increased fetal Cortisoljust before birth. Human prolactin causes synthesis of milk in the female breast. The half life of circulating growth hormone in humans is 20 to 30 minutes.


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BLOOD

Blood is a connective tissue in fluid form. Blood is 5 times viscous than water. Blood cell count is greater in children than adult. RBC is microcytic in iron defiency anaemia, prolonged forced breathing &

increased osmotic pressure.

RBC is macrocytic in megaloblastic anaemia, muscular exercise & decreasedosmotic pressure in blood.

Punctate basophlism is seen in lead poisoning. Goblet ring is seen in certain types of anaemia like malaria. Red cell vol. can be determined by radio isotope 51 Cr. Cyanosis appears when the reduced Hb cone, of the blood in the capillaries is more

than 5 gm/dl. In vitro, coagulation is initiated by factor XII. Life of RBC's in adult human body is 120 days. Average life span of RBC in a newborn is 100 days. Average life span of RBC in transfused blood is 90 days. Life span of transfused platelets is 4 days. Life span of platelets is 9-12 days. Complete erythropoiesis occurs in 7 days. Erythropoiesis occurs in

o In first trimester RBC's are formed in Yolk sac. While in second trimesterliver is the main organ. Third trimester in liver & bone marrow.

o Upto age of 5 6 yrs red bone marrow of all bones.o 6 20 yrs red bone marrow of all bones & all membranous bones.o After 20 yrs all membranous bones & ends of long bone.

Hb starts appearing in intermediate normoblastic stage of erythropoiesis. Nucleus disappears during late normoblastic stage. Factors needed for Erythropoiesis: erythropoietin, thyroxine, interleukins 3, 6, 11,

stem cell factors, Vit B, C & D. (maturation factors Vit B12 & folic acid). The iron remains in ferrous state. The affinity of Hb for CO2 is 20 times more than for O2. The affinity of Hb for CO is 200 times more than its affinity for O2. Adult Hb consists of 2 alpha & 2 beta chains. Fetal Hb consist of 2 alpha & 2 gamma chains.


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In sickle cell anemia, the 2 alpha chains are normal but 2 beta chains areabnormal.

In Hb C, beta chains are abnormal. Bilirubin is the final product formed from the destruction of Hb. Total quantity of the iron in the body is 4gm. 1 mg of iron is excreted every day through faeces. Normocytic normochromic anaemia is seen in aplastic aneamia. Marcocytic normochromic anaemia seen in folate deficiency, Vit B12 &

hypothyroidism.

Pernicious anaemia or addsion's anaemia is marcocytic normochromic anaemia. Microcytic hypochromic is seen in iron deficiency, thalassemia,

heamoglobinopathies & heamolytic anaemia.

ESR decreases in allergic conditions, sickle cell anaemia, polycythemia &afibrinogenemia.

Character Normal1. ESR Male: 3 7 mm / hr

Female: 5 9 mm / hr2. PCV (Packed cell

volume)

(Hematocrit)

Male: 40 45 %Female: 38 42 %

3. MCV (Mean

corpuscular volume)90 cu (78 90 cu)

4. MCH (Mean

corpuscular Hb)

30 pg (27 32pg)

5. MCHC (Mean

corpuscular Hb Conc.)30% (13 38%)

6. Colour index 1 (0.8 1.2)7. WBC 4000 11,000 / cmm8. D.C

Neutrophils

EosinophilsBasophilsMonocytesLymphocytes

50 70%2 4 %0 1 %2 6%20 30 %


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9. Platelet count 2,50,000( 2 lakhs 4 lakhs)10. Bleeding time 3 6 min11. Clotting time 3 8 min12. Prothrombin time 12 sec13. Activated partial

thromboplastin

time(APTT)

25 40 sec

14. RBCAdult maleAdult femaleBirth

4 5.5 millions / mm35 millions / mm34.5 millions / mm38 10 millions / mm3

15. HeamoglobinAdult maleAdult femaleNew born

14 18 gm / dl12 16 gm / dl16 22 gm /dl

16. RBCDiameter 7.5

17. Blood volume 5 liters Granulocytes are neutrophils, eosinophils & basophils. Agranulocytes are monocytes & lymphocytes. Monocyte is the largest lymphocyte. In hemophilia clotting time is prolonged in presence of normal bleeding time. Christmas disease occurs due to deficiency offactor IX. Clotting factors

Factor I FibrinogenFactor II ProthrombinFactor III ThromboplastinFactor IV CalciumFactor V Pro accelerin (labile factor)Factor VI No such factorFactor VII Stable factorFactor VIII Anti hemophilicFactor IX Christmas


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Factor X Stuart-powerFactor XI Plasma thrombplastin antecedentFactor XII Hegman (Conduct)Factor XIII Fibrin stabilizing factor (Fibrinase)

Blood group:Group Antigen in RBC Antibody in serumA A Anti B ()B B Anti AB A & B No anti bodyO No antigen Anti A & Anti B

Universal recipient are Blood Group 'AB because it does not contain either Anti Aab or anti B ab.

Universal donor is Blood Group "()" because it docs not contain either A or Bagglutinogen (antigen).

Commonest blood group is O. Diseases associated with blood groups:

o Group A C.A stomacho Group O duodenal ulcer

Normal basic acid output is 5-10 mmol/hour. Blood is stored in the blood bank at 40C.

The number of iron Heme in one Hb molecule is 4.

The number of O2 molecules carried by one Hb molecule is 4. Mean corpuscular diameter is 7.5 nm. Maximum concentration of Hb normally found in RBC's is 34%. In arterial blood, saturated Hb with 02 is 97%. Thromboxane A2 is synthesized by platelets and promotes vasoconstriction and

platelet aggregation. In sickle cell anemia, valine is substituted for glutamic acid. Platelets are derived from megakaryocytes. Pus contains Dead neutrophils, macrophages and necrotic tissues. Cardiac output in anemia is above normal while in polycythemia is about normal. Agglutinins are either IgM or IgG. In Erythroblastosis fetalis, mother is Rh-, father is Rh+, foetus is Rh positive. Hapatoglobin is a plasma protein responsible for carrying free Haemoglobin. Usual anticoagulant used for transfusion is a citrate salt.


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Earliest feature of iron deficiency anemia is decreased serum ferritin. Arneth count is used in the determination of the percentage distribution of different

types of neutrophils on the basis of no: nuclear lobes.

Wilsons disease is due to decrease in caeruloplasmin.

EXCRETORY SYSTEM Hormones secreted by kidney are erythropoietin, thrombopoitein, renin & 1, 25

dihydroxy cholecalciferol.

1 kidney contains about 1 1.3 millions nephrons. Ratio of corical nephrons to Juxtamedullary nephrons 85: 15. The GFR of average sized normal man is approximately 125 ml / minute or 180

liters / day.

At the rate of 125 ml/min, the kidneys filter an amount of fluid equal to 4 times theTBV, 15 times the ECF vol. and 60 times the plasma volume.

1 1.5 liters of urine formed / day. Urine osmolality in diabetes insipidus is 300 mmol/L. Normal protein excretion is 50 -150 mg%. The quantity of water lost as sweat per day is 600-800 C.C Normal urea clearance is 44 ml/min. Renal blood flow is 25% of cardiac output (1300 ml blood/min). Total length of distal convoluted tubule is 5 mm. Glomerulus membrane permits the passage of substances upto 4 nm and almost

totally excludes substance with size greater than 8 nm. Each glomerulus is a net work of approximately 50 parallel capillaries. Urinary osmolality in diabetes insipidus is 300 m mol/Lit. Glucose and amino acid are absorbed in proximal convoluted tubules by secondary

active transport or sodium Co-transport.

Descending limb of thin segment of loop of Henle is freely permeable towater.

Areas impermeable to water ascending limb of thin segment thick segment ofloop of Henle. Proximal half of convoluted tubule.

Areas impermeable to urea Distal convoluted tubule & cortical portion ofcollecting tubules.

Substances completely reabsorbed in PCT Glucose, proteins, amino acids,vitamins, acetoacetate.


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Substances partially absorbed in PCTNa. K, Cl (7/8 reabsorbed in PCT). Substances secreted in PCT H+, PAH (para amino hippurate). creatinine. H+ are actively secreted in proximal tubules, distal tubules, collecting ducts. Hyperosmilality in the interstitum is the prerequisite for excretion of concentrated

urine. Urea is reabsorbed from inner meduallary collecting ducts only in presence ofADH. K+ is actively secreted in Late Distal tubules and Collecting ducts. Macula densa is the epithelial cells of the distal tubule that comes to contact with

the arterioles. Juxtaglomerular cells produce renin. Renin acts on angiotensinogen & convert it into angiotensin I. Renal threshold for glucose is reduced in renal glycosuria. Creatinine clearance represents GFR. Clearance test for renal function includes inulin clearance, creatinine clearance &

PAHA test.

PAHA test is performed to assess renal blood flow. Micturition is primarily a spinal reflex. Thick ascending loop of henle is impermeable to water. Majority of sodium absorption occur in the proximal tubule.

Character NormalpH 4. 5 6Volume 1000 1500 ml / daySpecific gravity 1.010 1.025

MALE REPRODUCTIVE SYSTEM Average pH of semen is 7.5. Life span of spermatozoa within the female genital tract is upto 24 hours. Speed of human sperm in female genital tract is about 3 mm/min. Male sex hormones are called the androgens (secreted by leydig cells);

testosterone, dihydro testosterone & androstenedione.

Mullerian ducts gives rise to female accessory sex organs such as vagina, uterus &fallopian tube.

Wolffian duct gives rise to male accessory sex organs such as epididymis, vasdeferens & seminal vesicles.


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Fetal testes begin to secrete the testosterone at about 2nd to 4th month ofembryonic life.

The secretion from seminal vesicles contains fructose, phophorylcholine,fibrinogen, ascorbic acid, citric acid, pepsinogen, acid phosphatase & prostaglandin.

Fructose & citrate acts as fuel for the spermatozoa. Prostatic secretion is rich in enzymes, fructose & citrate. Androgen appears to be essential for spermatogenesis. Whereas FSH is required for

spermatic maturation. Testes do not produce fructose.(seminal vesicle) Sertoli cells provide nutrition to the developing sperm; secrete oestrogen &

hormone binding proteins.

Testosterone is synthesized from pregnanolone. Testosterone stimulates the process of spermatogenesis, also necessary for the

formation of secondary spermatocyte from primary spermatocyte.

Growth hormone is essential for the general metabolic processes in testis. Male sex hormone is secreted mainly by interstitial cells of Leydig. Development of male sex organ in fetal life depends on testosterone produced

under the influence of HCG. Testosterone circulates in Combination with Gonadal steroid binding globulin. Hormone used for treating osteoporosis in old age Testosterone. In males FSH promotes spermatogenesis by enhancing the transport of

Testosterone to seminiferous tubules and androgen binding protein synthesis from

sertoli cells.

FEMALE REPRODUCTIVE SYSTEM During menstrual period, upto 20 gm of protein may be lost. Quantity of blood expelled during normal menstral cycle is 40 ml (approx) & serous

35 mls.

FSH level is high in post menopausal women.

Ovarian hormones are estrogen and progesterone

Ovulation occurs on the 14th day of menstrual cycle in a normal cycle of 28 days. Oxytocin causes contraction of smooth muscles of uterus & enhances labour. Hormones secreted are HCG, Oestrogen, progesterone & human chorionic somato

mammo tropin.


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Relaxin is a hormone secreted from the maternal ovary during the later periods ofpregnancy.

Biological test for Pregnancy can be performed only after 2 3 weeks ofconception.

LH is concerned with follicle maturation and ovulation. Menopausal hot flushes are due to LH surge. Estrogen increases the secretion and ciliary beating in fallopian tubes. Estrogen changes the cuboidal lining of vagina to stratified. Estrogen changes the break down of glycogen into lactate in vagina. Estrogen initiates breast development. Estrogen causes early epiphyseal closure. Estrogen causes water retention. Important function of progesterone is to promote secretory changes in

endometrium. Progesterone is the hormone for maintenance of pregnancy. Progesterone inhibits ovulation. The most important function of progesterone is to promote secretory changes in

endometrium.

WATER & ELECTROLYTE / ACID-BASE BALANCE In human beings the total body water varies from 45 75 % of body weight. Total water in the body is about 40 liters. (ICF forms 55% & ECF forms 45%). The volume of interstial fluid is about 12 liters. The volume of plasma is about 2.75 liters. Osmolalityis the measure of a fluids capability to create osmotic pressure, also

called as osmotic conc. of a solution.

Osmolarity is the no: of particles / per liter of solution. Isotonic solutions are having same effective osmolality as body fluids. Eg: 0.9%

Nacl solution & 5% glucose solution.

The insensible water loss from the body is about 600 to800 ml. per day.

The quantity of water lost as sweat per day is 600 800 C.C. The normal pH of plasma is 7.4 Acidosis is pH below 7.38 Alkalosis is pH above 7.42 Respiratory acidosis: primary excess of carbonic acid


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o Due to hypoventilation as in respiratory diseases & neural diseases. Metabolic acidosis: primary deficiency of bicarbonate

o As in lactic acidosis, diabetic ketoacidosis, uremic acidosis & diarrhea. Respiratory alkalosis: primary deficiency of carbonic acid

o Due to hyperventilation as in hypoxia, neural diseases & psychologicalconditions.

Metabolic alkalosis: primary excess of bicarbonateo As in vomiting & treatment with diuretics.

14146264 Physiology Last Moment Revisions Copy

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