Physiology last-moment-revisions
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PHYSIOLOGY - Last moment revisions
Muscle Physiology
·Muscle 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 & don’t 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 system
·The 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 / min
o AV node : 40 to 60 / min
o Atrial muscle : 40 to 60 / min
o Ventricular muscle : 20 to 40 / min
· Velocity of impulse at different parts of the conductive system.
o Atrial muscle fibres : 0.3 meter / second
o Internodal fibers : 1.0 meter / second
o AV node : 0.05 meter / second
o Bundle of his : 0.12 meter / second
o Purkinje fibers : 4 meter / second
o 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 0.8
sec.
· The duration of systole is 0.27 sec & that of diastole is 0.53 sec.
· The subdivision with duration are
o Systole
§ Isometric contraction = 0.05 sec
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§ Ejection period = 0.22 sec
o 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 ventricles
is 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 Right
Atrium
Left
Atrium
Right
Ventricle
Left
Ventricle
Systemic
Aorta
Pulmonary
artery
Max
(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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· Cause for cardiac murmurs
Systolic murmur Diastolic murmur Continuous
murmur
1. Incompetence of AV
valve
2. Stenosis of
semilunar valves
3. Anemia
4. Septal defect
5. Coarctation of aorta
1. Stenosis of AV valve
2. Incompetence of
semilunar valves
Patent
ductus
arteiosus
· Electrocardiography:
Duration
o Interval B/W 2 thick lines: (5mm) = 0.2 second
o Interval B/W 2 thin lines (1mm) = 0.04 second
Amplitude
o Interval B/W 2 thick lines: (5mm) = 0.5 mV
o Interval B/W 2 thin lines (1mm) = 0.1 mV
Speed of the paper
o 25 mm or 50 mm / second
§ Normal heart rate is 72 / min
§ Tachycardia: increase heart rate above 100 / min.
Waves of normal ECG
Wave /
segment
From – to Cause Duration
(second)
Amplitude
(mV)
P wave - Atrial
depolarization
0.1 0.1 to 0.12
QRS
complex -
Ventricular
repolarization
0.08 – 0.10 Q=0.1 – 0.2
R=1
S=0.4
T wave - Ventricular
repolarzation
0.2 0.3
P – R
interval
Onset of P
wave to
onset of Q
wave
Atrial
depolarization &
conduction through
AV node
0.18 (0.12 to
0.2) -
5
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 Isometric
contraction
& ejection
period
Closure of
AV valves
Long, soft, &
low pitched.
Resembles the
word ‘LUBB’
0.10 –
0.17
‘R’ wave
Second Protodiastole
& part of
isometric
relaxation
Closure of
semilunar
valves
Short, sharp,
& high pitched.
Resembles the
word ‘DUBB’
0.10 –
014
Precedes
or
appears
0.09 sec
after
summit
of ‘T’
wave
Third 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 –
0.04
B/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. Normal
value: 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 Percentage
Liver 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 contraction
3. Heart rate
4. 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 Less in 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 periphery
o Renal mechanism: by regulation of ECF volume & rennin-angiotensin
mechanism.
o Local mechanism
Local vasoconstrictors & Local vasodilators
o Hormonal mechanism:
Hormones increase BP Hormones decrease BP
Adrenaline
Noradrenaline
Thyroxine
Aldosterone
Vasopressin
Angiotensin
Serotonin
Vasoactive intestinal
polypeptide(VIP)
Bradykinin
Prostaglandin
Histamine
Acetylcholine
Atrial 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 Hg
o 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 ‘a’ wave – 1st positive wave & it’s due to atrial systole.
o ‘x’ wave – fall of pressure in atrium, coincides with atrial diastole
o ‘c’ wave – 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 ‘v’ wave – occurs during isometric relaxation period or during atrial diastole.
o ‘y’ wave – 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:
§ Touch receptors: Meissner’s corpuscle & Merkel’s disc (max in lips & fingers)
§ Pressure receptors: Pacinian corpuscles
§ Temperature receptor
o Cold: Krause’s end organ
o Warm: Raffini’s end organ
o Warm receptors respond at body temperature of— 30 - 45°C.
o Cold receptors are activated at body temperature of— 10°C 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 Excitatory neurotransmitter: is responsible for the conduction of impulse from
the presynaptic neuron to the
postsynaptic neuron.
o Inhibitory neurotransmitters: inhibits the conduction of impulse from the
presynaptic neuron to the postsynaptic neuron.
Group Name Action
Amino acids
GABA Inhibitory
Glycine Inhibitory
Glutamate Excitatory
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Aspartate Excitatory
Amines
Adrenaline Inhibitory & Excitatory
Noradrenaline Inhibitory & Excitatory
Dopamine Inhibitory
Serotonin Inhibitory
Histamine Excitatory
Others Nitric oxide Excitatory
Acetylcholine Excitatory
· Superficial reflexes:
Reflex Stimulus Response Center
Corneal Irritation of cornea Blinking of eye Pons
Conjunctival Irritation of
conjuctiva
Blinking of eye Pons
Nasal Irritation of nasal
mucus membrane
Sneezing Motor
nucleus of V
cranial nerve
Pharyngeal Irritation of
pharyngeal mucus
membrane
Retching of
gagging
Nuclei of X
cranial nerve
Uvular Irritation of Uvula Raising of Uvula Nuclei of X
cranial nerve
· Superficial cutaneous reflexes
Reflex Stimulus Response Center –
spinal
segment
involved
Scapular
Irritation of skin at the
interscapular space
Contraction of
scapular muscles &
drawing in of
scapula
C5 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
Cremasteric
Stroking the skin at
upper & inner aspect
of thigh
Elevation of testicles
L1, L2
Gluteal Stroking the skin over
glutei
Contraction of glutei L4 to S1,
S2
Plantar Stroking the sole Plantar flexion &
adduction of toes L5 to S2
Bulbocavernous Stroking the dorsum
of glans penis
Contraction of
bulbocavernous S3, S4
Anal Stroking the perianal
region
Contraction of anal
sphincter S4, S5
· Deep reflexes
Reflex Stimulus Response Center –
spinal
segment
involved
Jaw jerk
Tapping middle of the
chin with slightly opened
mouth
Closure of mouth Pons – V
cranial
nerve
Biceps jerk Percussion of biceps
tendon
Flexion of forearm C5, C6
Triceps jerk Percussion of triceps
tendon
Extension of
forearm C6 to C8
Supinator jerk
or radial
periosteal
Percussion of tendon
over distal end (Styloid
process) of radius
Supination &
flexion of forearm C7, C8
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reflex
Wrist tendon or
finger flexion
reflex
Percussion of wrist
tendons
Flexion of
corresponding
finger
C8, T1
Knee jerk or
Patellar tendon
reflex
Percussion of patellar
ligament
Extension of leg
L2 to L4
Ankle jerk or
Achilles tendon
reflex
Percussion of Achilles
tendon
Plantar flexion of
foot L5 to S2
Pathological reflexes:
Babinski’s 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 of spinal nerves. (C-8; T-12; L-5; S-5; C-1)
Grey matter is the collection of nerve cell bodies, dendrites & parts of axons.
White matter is a collection of myelinated & nonmyelinated nerve fibers.
Neurons in the grey matter of spinal cord
Neurons in Anterior gray horn
Alpha motor neurons; Gamma motor neurons & Renshaw cells
Neurons in lateral gray horn
Intermediolateral horn cells
Neurons in posterior gray horn
Substania gelatinosa of Rolando; Marginal cells; Chief sensory cells &
Clarke’s column of cells.
Ascending tracts of Spinal cord:
Situation Tract Function
Anterior white
funiculus Anterior spinothalamic tract Crude touch sensation
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Lateral white
funiculus
Lateral spinothalamic tract Pain & temperature sensation
Ventral spino cerebellar tract Subconscious kinesthetic
sensations
Dorsal spino cerebellar tract Subconscious kinesthetic
sensations
Spinotectal tract Concerned with spinovisual reflex
Fasiculus dorsolateralis Pain & temperature sensations
Spinoreticular tract Conciousness & awareness
Spinoolivary tract Proprioception
Spinovestibular tract Proprioception
Posterior
white
funiculus
Fasciculus gracilis Tactile sensation
Tactile localization
Tactile discrimination
Vibratory sensation
Conscious kinesthetic sensation
stereognosis
Fasciculus cuneatus
Descending tracts of Spinal cord:
Situation Tract Function
Pyramidal
tracts
Anterior corticospinal
tract Control voluntary movements
Forms upper motor neurons Lateral corticospinal
tract
Extra
Pyramidal
tracts
Medial longitudinal
fasciculus
Coordination of reflex ocular movement
Integration of movements of eyes & neck
Anterior vestibulospinal
tract
Maintenance of muscle tone & posture
Maintenance of position of head & body
during acceleration Lateral vestibulospinal
tract
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 to
visual & 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 lower
motor
neuron
lesion
Clinical
observation
Muscle tone Hypertonic Hypotonic
Paralysis Spastic type of paralysis Flaccid type
of paralysis
Wastage of muscle No wastage Present
Superficial reflexes Lost Lost
Plantar reflex Abnormal – babinski’s
sign
Absent
Deep reflexes Exaggerated Lost
Clonus Present Lost
Clinical
confirmation
Electrical activity Normal Absent
Muscles affected Groups of muscles are
affected
Individual
muscles are
affected
Fascicular twitch in
EMG
Absent present
Action of sympathetic & parasympathetic divisions of ANS:
Effector organ Sympathetic division Parasympathetic
division
Eye Ciliary muscle Relaxation Contraction
Pupil Dilatation Constriction
Lachrymal secretion Decrease Increase
Salivary secretion
Decrease in secretion &
vasoconstriction
Increase in
secretion &
vasoconstriction
GIT
Motility Inhibition Acceleration
Secretion Decrease Increase
sphincters constriction Relaxation
Gall bladder Relaxation contraction
Urinary bladder Detrusor muscle Relaxation contraction
Internal sphincter Constriction Relaxation
Sweat glands Increase in secretion -
Heart rate & force Increase decrease
Blood vessels Constriction of all blood Dilatation
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vessels except those in
heart & skeletal muscle
Bronchioles 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 oblongata
·Respiratory 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 balls
Thalamus: 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 movement
Area 4S – suppressor area.
Inhibits movements initiated by
area 4.
Pre motor area
Area 6 – concerned with
coordination of movements
initiated by area 4.
Area 8 – frontal eye field.
Area 44 & 45(broca’s area) –
motor area for speech.
Supplementary
motor area
Concerned with co-ordinated
skilled movements.
Pre – Silent area or Area – 9 to 14, 23, 24, 29 &
18
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 perception
Area 2 & 3 – integration of
these sensations. Spatial
recognition. Recognition of
intensity, similarities & diff. B/W
stimuli
Somesthetic area II Concerned with perception of
sensation.
Somesthetic association area
Synthesis of various sensations
perceived by S.Area-I.
Stereognosis.
Temporal
lobe
Primary auditory area Area 41, 42 & wernicke’s
area – concerned with
perception of auditory impulses,
analysis of pitch, determination
of intensity & source of sound
Auditopsychic area Area 22 – interpretation of
auditory sensation
Area of equilibrium Maintenance of equilibrium
Occipital
lobe
Primary visual area Area 17 – perception of visual
impulse
Visual association area Area 18 - Interpretation of
visual 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 formation
·Major 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 / sec
Amplitude: 50µU.
Most marked in parieto-occipital area.
Obtained in inattentive brain as in drowsiness & light sleep.
·Beta rhythm:
Frequency: 15 to 60 waves / sec
Amplitude: 5 - 10µU.
Recorded during mental activity or mental tension or arousal state.
·Delta rhythm:
Frequency: 1 to 5 waves / sec
Amplitude: 20 - 200µU.
Seen in tumour, epilepsy, increased intracranial pressure & mental depression.
·Theta rhythm:
Frequency: 4 to 8 waves / sec
Amplitude: 10µU.
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)
20
Eye balls move Absent
Dreams occur Absent
Muscle twitching Absent
20 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 nuclei
·Parasympathetic nervous system is controlled by — Anterior nuclei and part of middle
nuclei of hypothalamus.
EYE:
§Refractory power is 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 – Red
o Iodopsin – Green
o Cyanopsin – Blue
§ Electroretinogram is the instrument to record the electrical basis of visual process.
§ Test for visual acuity – snell’s chart (distant vision) & Jaeger’s chart (near vision).
§ Test for color blindness – Ishihara’s colour chart.
§ Mapping of visual field – perimetry.
§ Nearest point at which the object is seen clearly is about 7 to 40cm.
§ Farthest point is 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:
21
§ 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 liquid
diet / day.
Auerbach’s plexus regulate the movements of GIT.
Meissner’s plexus regulate the secretory functions of GIT.
Auerbach’s 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 of Saliva:
· 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).
22
· 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 of gastric juice:
· Volume: 1200 – 1500 ml / day.
· Reaction: pH 0.9 – 1.2.
· Specific gravity: 1.002 – 1.004
· Composition: 99.5% water & 0.5% solids.
· Digestive enzymes: Pepsin, Gastric lipase & other gastric enzymes.
· Action of pepsin: attacks peptide bonds adjacent to aromatic amino acids by
hydrolysis.
· Action of gastric lipase: weak lipolytic enzyme becomes active only when pH is
between 4 & 5.
· Action of HCL: 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 of Pancreatic Juice:
· Volume: 500 – 800 ml / day.
· Reaction: pH 8 – 8.3.
· Specific gravity: 1.010 – 1.018
· Composition: 99.5% water & 0.5% solids.
· 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 of iron absorption.
23
· 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 5 mm 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 of Bile:
o Volume: 800 – 1200 ml / day
o Reaction: alkaline
o pH: 8 – 8.6
o 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 of bile 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 of succus entericus:
o Volume: 1800 ml / day
o Reaction: alkaline
o pH: 8 – 8.3
o 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 in
small intestine.
Peristaltic movements peristaltic rush are the two movements involved in the
pushing of chyme towards aboral end on intestine.
Desire for defecation is elicited by an increase in the intrarectal pressure to about
20 to 25 cm H2O.
Gastrointestinal hormones:
Hormone Source of
secretion
Actions
Gastrin G cells of
stomach;
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 of
duodenum,
jejunum & ileum
Stimulates secretion of watery,
alkaline & pancreatic secretions.
Cholecytokinin I cells in
duodenum,
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 Product
Mouth Saliva Salivary amylase Polysaccharides Disaccharides
Stomach Gastric
juice
Gastric amylase Weak amylase The action is
negligible
Small Pancreatic Pancreatic Polysaccharides Disaccharides –
25
intestine juice amylase Disaccharides dextrins, maltose &
maltriose
Monosaccharides
Succus
entericus
Sucrase
Maltase
Lactase
Dextrinase
Trehalase
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.
26
Average area of the alveolar walls in contact with capillaries in both lungs is about
70 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 2/3rd alveolar air + l/3rd dead 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 O2 to 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 Bohr’s effect.
The degree of stimulation of chemoreceptors depends on arterial PO2.
Spirometer cannot measure 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.
27
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 Inspiration — Diaphragm and External Intercostals muscle (Others -
Stcrnocleidomastoid, Serratus anterior).
Muscle of Expiration —Internal 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 left
Decrease pH Increase pH
Increase in temp decrease in temp
Excess of 2, 3 DPG Foetal blood
Increase 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 are
o Growth hormone or somatotropic hormone
28
o Thyroid stimulating hormone
o Adenocorticotropic hormone
o Follicle stimulating hormone
o Luiteinizing Hormone or interstitial cell stimulating hormones in males
o Prolactin.
Posterior pituitary hormones are
o Antidiuretic hormone or vasopressin
o 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 epiphysis
with 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 in
adults.
Parathormone is secreted by para thyroid gland & its main function is to increase
the 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
29
o Beta cells – Insulin
o Delta cells – Somatostatin
o 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 of
glucocorticoids.
Conn’s syndrome is primary aldosteronism.
Addison’s disease is chronic adrenal insuffiency.
Hormones of Adrenal medulla (Catecholamines) are
o Adrenaline or epinephrine
o Noradrenaline or norepinephrine
o Dopamine
Pheochromocytoma is a condition in which there is excessive secretion of
catecholamines.
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 Cortisol just 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.
30
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 & decreased
osmotic 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 trimester
liver 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.
31
In sickle cell anemia, the 2 alpha chains are normal but 2 beta chains are
abnormal.
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 Normal
1. ESR Male: 3 – 7 mm / hr
Female: 5 – 9 mm / hr
2. PCV (Packed cell
volume)
(Hematocrit)
Male: 40 – 45 %
Female: 38 – 42 %
3. MCV (Mean
corpuscular volume)
90 cuµ (78 – 90 cuµ)
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 / cmm
8. D.C
Neutrophils
Eosinophils
Basophils
Monocytes
Lymphocytes
50 – 70%
2 – 4 %
0 – 1 %
2 – 6%
20 – 30 %
32
9. Platelet count 2,50,000( 2 lakhs – 4 lakhs)
10. Bleeding time 3 – 6 min
11. Clotting time 3 – 8 min
12. Prothrombin time 12 sec
13. Activated partial
thromboplastin
time(APTT)
25 – 40 sec
14. RBC
Adult male
Adult female
Birth
4 – 5.5 millions / mm3
5 millions / mm3
4.5 millions / mm3
8 – 10 millions / mm3
15. Heamoglobin
Adult male
Adult female
New born
14 – 18 gm / dl
12 – 16 gm / dl
16 – 22 gm /dl
16. RBC
Diameter
7.5 µ
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 of factor IX.
Clotting factors
Factor I Fibrinogen
Factor II Prothrombin
Factor III Thromboplastin
Factor IV Calcium
Factor V Pro accelerin (labile factor)
Factor VI No such factor
Factor VII Stable factor
Factor VIII Anti hemophilic
Factor IX Christmas
33
Factor X Stuart-power
Factor XI Plasma thrombplastin antecedent
Factor XII Hegman (Conduct)
Factor XIII Fibrin stabilizing factor (Fibrinase)
Blood group:
Group Antigen in RBC Antibody in serum
A A Anti – B (β)
B B Anti – α
AB A & B No anti body
O No antigen Anti A & Anti B
Universal recipient are Blood Group 'AB because it does not contain either Anti A
ab or anti B ab.
Universal donor is Blood Group "()" because it docs not contain either A or B
agglutinogen (antigen).
Commonest blood group is O.
Diseases associated with blood groups:
o Group A – C.A stomach
o 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.
34
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.
Wilson’s 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 the
TBV, 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 to
water.
Areas impermeable to water — ascending limb of thin segment thick segment of
loop of Henle. Proximal half of convoluted tubule.
Areas impermeable to urea — Distal convoluted tubule & cortical portion of
collecting tubules.
Substances completely reabsorbed in PCT — Glucose, proteins, amino acids,
vitamins, acetoacetate.
35
Substances partially absorbed in PCT—Na. 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 of ADH.
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 Normal
pH 4. 5 – 6
Volume 1000 – 1500 ml / day
Specific 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, vas
deferens & seminal vesicles.
36
Fetal testes begin to secrete the testosterone at about 2nd to 4th month of
embryonic 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 of
pregnancy.
Biological test for Pregnancy can be performed only after 2 – 3 weeks of
conception.
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.
Osmolality is the measure of a fluid’s 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 to 800 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 & psychological
conditions.
Metabolic alkalosis: primary excess of bicarbonate
o As in vomiting & treatment with diuretics.
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