Physio Uhs Solved Past Papers 2nd Year(2)

7/28/2019 Physio Uhs Solved Past Papers 2nd Year(2)

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PHYSIOLOGY UHS PASTPAPERS (SOLVED)

2004-2012Brought to you by:

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GOD helps you & we are the source,

Help others to get helped!!


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SPECIAL SENSES

Q 1:What changes occur in eyes when these are focused

on a near object ? Explain the nervous mechanism

invovled?(2005 annual, 2008 annual)

Ans: (JP chp 169, Guyton chp 49)

Accomodation is invovled in this mechanism.

Definition : When eyes are focused on a near object

accomodation occurs ,the process by which light rays from

near objects or distant objects are brought to a focus on the

sensitive part of retina .It is achieved by various adjustments

made in the eyeball.

Mechanism:

1:contraction of cilliary muscles ,release ligament tension on

lens

2:lens assumes a spherical shape

3:suspensry ligaments are slackened

4:convergance of eyeballs

all the changes during accomodationovvurs simultaneously ,it


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can be controlled by will power to a extent.

Nervous mechanism:

Afferent pathway :

visual impulses on retina ->optic nerve ->optic chiasma-

>optic tract->lateral geniculate body->optic radiation to

visual cortex of occipital lobe ->association fibers to frontal

lobe

Centre:

located in frontal lobe of cerebral cortex (area 8 )

Efferent pathway :

1:Efferent fibers to ciliary muscles and sphincter pupillae

from area 8 ->corticulonuclear fibers pass via internal capsule

to EdingerWestphal nucleus of 3rd cranial nerve->preganglionic fibers pass to ciliary ganglion -

>postganglionic fibers via short ciliary nerves and supply

ciliary muscles and constrictor muscles

2:Efferent fibers to medial rectus :

from frontal eye field fibers to nucleus of occulomotor nerve ->and supply medial rectus


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Q 2:Draw the Rhodopsin visual cycle . What is the

outcome of Vit.Adeficiency ?(2006 annual ,2007 annual )

Ans : Guyton chp 50

Rhodopsin visual cycle :

Diagram from guyton page 611

Role of Vit. A for formation of Rhodopsin :

1:Vit.A is present in cytoplasm of rods and in the pigment

layer of the retina to form new RETINAL .

2:When excess retinal ,it is converted back into Vit.A and vice

versa .

Deficiency of Vit.A :

1:Outcome of Vit.A deficiency is Night blindness.

2:Retinal and rhodopsin formation is severly depressed.

3:For night blindness to occur person must remain on Vit.A

deficient diet for at least 3 months because large quantities of

it are mostly stored in liver.

4:It can be reversed in less than 1 hour by intravenousinjection of Vit. A.


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Q 3:Draw pathway for light reflex . What is consensual

light reflex ?(2006 supplementry)

Ans : (Guyton chp 51, JP chp 169 )

Light Reflex pathway:

light rays on eyes->optic nerve->optic chiasma->optic tract-

>pretactal nucleus->EdingerWestphal nucleus->ciliary

ganglion->short ciliary nerve(parasympathetic nerves)-

>constrict sphincter of iris

Consensual Light Reflex:

1:Contraction in both eyes when light thrown in one eye.

2:The reason for Consensual light reflex is that some of the

fibers from pretactal nucleus of one side cross to the opposite

side and end on the opposite EdingerWestphal nucleus.

Q 4:A 65 years old man reports to his physician with the

principle complaint of Nyctalopia (nightbilndness).(2009

annual)

a.What is the cause of this disorder?

Vit.A deficiency

b.Which layer of retina becomes impair?


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Pigmented layer , as Vit.A is stored in this layer and Layer of

rods as well because Vit. A involved in formation of retinal and

rhodopsin.

c.What is Argyll Robertson Pupil?

It is clinical condition in which the light reflex is lost but the

accomodation reflex is present . Pupil is also very small .It is

an important diagnostic sign of CNS disease such as SYPHILIS.

Q 5:Miss R is very selective in her diet . From last few

months she is complaining of difficulty to see at night ,

she is diagnosed to be suffering from Night Blindness

.(2010 annual)

a.What is the cause of Night Blindness?

Vit.A deficiency in diet.

b.What will be the role of her treatment in the formation

of Rhodopsin ?

Intravenous injection of Vit.A can can reverse night blindnessin less than 1 hour because Vit.A is used in the formation of

retinal and rhodopsin .


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Q 6:How do eyes adapt to bright light and darkness?Give

its significance . (2008 supplementry)

Ans: (Guyton chp 50)Light Adaptation:

1:Process in which eyes get adapted to increased illumination.

2:Photochemicals in both rods and cones will have been

reduced to retinal and opsins.

3:Much of the retinal of both rods and cones will have been

converted into Vit.A .

3:Because of these two effects conc. of photosensitive

chemicals remaining in the rods and cones are considerably

reduced and sensitivity of the eye to light is correspondingly

reduced .this is called light adaptation.

Dark Adaptation:

1:If a person remains in the darkness for a long time , the

retinal and opsins in the rods and cones are converted back

into light sensitive pigments.

2:Furthermore,Vit.A is converted back into retinal to increaselight sensitive pigments , the final limit being determined by

the amount of opsind in the rods and cones to combine with

the retinal.This is called dark adaptation.


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3:Dark adaptation curve , guyton page no. 614.

Other mechanism of light and dark adaptation:

1:Change in pupillary size (adaptation upto 30 folds within

fraction of seconds because of changes in the amount of light

allowed through the pupillary opening)

2:Neural adaptation, through bipolar cells, horizontal

cells,amacrine cells and ganglion cells , signals first are strong

then decrease rapidly at different stages of

transmission.Degree of adaptation is only fewfolds but occurs

in fraction of seconds , in contrast to the many to hours

required for full adaptation by the photo chemicals.

Significance:

Person is able to see in the illumination as well as in the dim

light .

Q 7:A student of 5th class feels difficulty in reading from

the blackboard while sitting in back benches of the

class?(2008 annual BDS )(Ans: Guyton chp 49)a:From which refrective error , the student is most likely

to be suffering?

MYOPIA


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b:What is the cause of this error?

In myopia, when ciliary muscle is completely relaxed , the light

rays coming from distant objects are focused in front of the

retina .This is usually due to too long as eyeball ,but it can

result from too much refrective power in the lens system of

eye.Myopic person has no mechanism by which to focus

distant objects sharply on the retina.

c:Which lens are used to correct these errors?The light rays passing through a concave lens diverge.If the

refractive surfaces of the eye have too much refractive power

,as in myopia, this excessive refractive power can be

neutralized by placing in front of the eye a concave spherical

lens , which will diverge rays.

Q 8:What is Attenuation Reflex ? What is its

significance?(2006 supplementry, 2005 annual)

Ans:(Guyton chp 52 )

1:This reflex is characterized by involuntary contraction oftensor tympani and stapedius muscles in respose to loud

noise.


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2:Its latent period is 40 to 80 miliseconds .

3:The tensor tympani muscle pulls the handle of malleus

inward while the stapediusmusle pulls the stapes outward.

3:These two oppose each other and thereby cause the entire

ossiculay system to develope increased rigidity , thus greatly

reducing the ossicular conduction of low frequency sound ,

mainly frequencies below 1000 cycles per second.

4:It can reduce the intensity of low freq. sound transmission

by 30 to 40 decibles, which is about the same difference as

that b/w a loud voice and a whisper.

Significance:

1:To protect the cochlea from damaging vibrations caused byexcessive loud sound.

2:To mask low freq. sound in loud environments.

3:Decrease a persons hearing sensitivity to his or her own

speech.

Q 9:Howossicular system in middle ear transmit sound

waves ? What is its significance ?(2010 annual)


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Ans:(Guyton chp 52)

Attached to tympanic membrane is handle of malleus, this

point is pulled by tensor tympani which keeps the membrane

pulled.

This allows the sound vibrations on any portion of the

tympanic membrane to be transmitted to the ossicles.

Ossicles of middle ear are suspended by ligament in such a

way that the combined malleus and inscusact as a single

lever,have approximately atthe border of the tympanic

membrane.

The articulation of the incus with the stapes causes the stapes

to push forward on the oval window and on the cochlear fluid

on the other side of window.

Significance:

Main significance of ossicular system is impedance matching.

Q 10: What is place principle for determining of pitch of

sound?(2006 annual)

Ans:(Guyton chp 52)


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1: It is apparent that low freq.sounds cause maximal activation

of the basilar membrane near the apex of the cochlea, and

high freq.sounds activate the basilar membrane near the baseof the cochlea.

2:Therefore, the major method used by the nervous system to

detect different sound freq is to determine the positions

along the basilar membrane that are most stimulated.This is

called place principle.

Q 11:How can you differentiate b/w conductive deafness

and perceptive deafness?(2004 annual)

Ans: (Guyton chp 52)

1:Deafness caused by impairment of cochlea , the auditory

nerve, or the central nervous system circuitsfrom the ear ,

which is usually classified as nerve deafness.

2:Deafness caused by impairment of the physical structure of

the ear that conduct sound itself to the cochlea ,which is

usually called conduction deafness.

Difference:

The difference can be determined by different tests as follow:


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1:Rinnes Test

2:Webers Test

3:Audiometry

Q 12:A bomb blast occurs in the vicinity of a house . A

woman present in the house is hit by a piece (sharpnel)of

the bomb on her right arm. She also feels that her hearingis also slightly impaired .Her complete examination in

emergency reveals no auditory damage of deficit . Few

minutes later she has no complaint of hearing loss.

a: What is mechanism which protects the ear from

damage due to loud sound?

b:Whar are the benefits/function of this mechanism?

(2012 annual)

Ans:Same as that of question no.8

Prepared by :Ayesha Arshad and ArshiaAnjum

FMH College Of Medicine and Dentistry


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Lahore.

NEUROPHYSIOLOGY

Q:What are the features of upper motor neuron lesion?Give

one example of the lesion?

Ans:Features:

a)-Paralysed muscles are rigid(spastic paralysis)

b)-Deep reflexes are exagerrated(Hyper-reflexia)

c)-Abdominal and cremasteric reflexes are lost

d)-Plantar reflex becomes Babinski,s sign

e)-No wasting or little wasting of muscles

f)-Reaction of degeneration is absent

g)-Large area of body involved

Example


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Cerebral Palsy

Q-What are the functions of CSF?Why is lumbar puncture

generally performed below L2 segment of spinal cord?

Ans:Functions of CSF:

i)-Acts as shock absorber

ii)-Acts as cushion between soft and delicate brain and rigid

cranium

iii)-Acts as a fluid buffer

iv)-Acts as a reservoir to regulate contents of cranium.

v)-medium for nutritional exchange

vi)-Removes metabolites

vii)-Transports medicine

Lumbar puncture is performed below L2 segment to avoid

injury to spinal cord.The spinal cord terminates at this level.Q-Name tactile receptors.Why does asterognosis occur due to

lesion of dorsal column tract?


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Ans:Tactile Receptors:

i)-Free nerve endings

ii)-Expanded tip endingsiii)-Merkel,s discs

iv)-Spray Endings

v)-Ruffini,s Endings

vi)-Kraus,s endings

vii)-Meissner,s Endings

Dorsal column tract is responsible for the sensations of touch

,two point discrimination,proprioception and position.We get

an idea of the shape of the object by touching it.So lesion of

dorsal column tract results in astereognosis which is the

inability to identify an object by touch without visual input.

Q-Write a note on Analgesia Sytem?

Ans:Analgesia System:

Brain can supress input of pain signals to the nervous systemby activating a pain control system,called the analgesia

system.


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Components:

i)-The periaqueductal and periventricular areas of the

mesencephalon ant upper pons surround the aqueduct ofSylvius and portions of the 3rd And 4th ventricles.Neurons

from these areas send signals to:

ii)-The Raphe Magnus Nucleus, a thin midline nucleus located

in the lower pons and upper medulla and the nucleus

reticularisparagigantocellularis.From these second order

signals are transmitted to:

iii)-A pain inhibitor complex located in the dorsal horns of the

spinal cord.

Areas that excite the periaqueductal gray area can also

supress the pain.Theseare :

i)-Periventricular area

ii)-Medial forebrain bundle

Main transmitter substances involved are :

Enkaphalin and Serotonin

Enkaphalin is believed to cause both presynapticand post-synaptic inhibiton of incoming type C

and type A delta fibers.


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Brain Opiate System: Endorphins and Enkaphalin

*Injection of the minute quantities of morphine

either into the periventricular nucleus aroundthird ventricle or into the periaqueductal gray

Area of the brainstem causes an extreme degree of analgesia

Q-Enemurate functions of Cerebellum.List 4 features of

cerebellar diseases.

Ans.Functions:

i)-Planning and fine tunning of skeletal muscle contraction

ii)-Maintainance of posture and performance of voluntary

muscles

iii)-Facilitates smooth and co-ordinated voluntary movementsiv)-Ensures that force,contraction and extent of movements

are accurate.

v)-Rsponds to vestibular stimuli from inner ear

vi)-Assists in maintaing equilibrium by modifications in muscle

tone

4 Features of cerebellar diseases:

i)-Dysmetria and ataxia


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ii)-Past pointing and dysdiadochokinesia

iii)-Dysarthia

iv)-Intention tumor

Q-Write the effects of sympathetic stimulation

on thoracic and abdominal viscera?

ORGAN EFFECT

HEART MUSCLES

coronariesIncreased Rate

Increased Force of

contraction

Dilated(beta

2),Constricted(alpha)

LUNGS

Bronchi

Blood vessels

Dilated

Mildly Constricted

GUT LUMEN

Sphincters

Decreased peristalsis and

tone

Increased Tone


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Liver

gallbladders & bile duct

Glucose released

Relaxed

kidney Decreasd urine output and

increased renin secretion

Bladder

detrusor muscle

trigone

Relaxed

Contracted

Q-Explain the flexor or wtihdrawal reflex with the help

of a diagram?

Neuronal Mechanism of the flexor reflex:

The pathway for eliciting the flexor reflex passes first into the

spinal cord interneuoron pool of neurons and only

secondarily to the motor neurons.The shortest possiblecurcuit is a 3 or 4 neuron pathway,however most of the

signals of the reflex transverse many more neurons and

invovle the following basic types of curcuits


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i)-Diverging curcuits to spread the reflex to the necessary

muscles for the withdrawal

ii)-Curcuits to inhibit the antagonist muscles

iii)-Curcuits to cause afterdischarge lasting many fractions of a

second after the stimulus is over

Within a few milliseconds,after a pain nerve fiber begins to be

stimulated ,the flexor response appears.Then in the next fewthe flexor response begins to fatigue.Finallyy after the

stimulus is over,there is a period of after-discharge

Q-What is the motor and sensory loss at and below the level

of hemisection of the spinal cord.

Ans:Effects at the level of lesion:

On the Same side:

Sensory Loss:

Complete anaesthesia to all forms of senses,because post

nerve root,post horn cells and lat and ventralspinothalamictracts crossing to the opposite side are all lost

Motor disturbances:

Paralysis of lower motor neuron type due to


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Damage to ant horn

On the opposite side:

Sensory Loss:

Nil or very slight

Motor Loss:

Nil or slight due to damage to small direct pyramidal fibers

of same side

EFFECT BELOW THE LEVEL OF LESION:

On the same side:

Sensory Disturbances:

*Fine touch and proprioception are lost due to damage to

fasciculi gracilis and cuneatous which do not cross*Pain,temperature and crude touch are not lost because

lateral and ventral spinothalamic tracts cross to opposite sides

below the level of lesion

Motor Disturbances :

Paralysis of upper motor neuron lesion type

ON OPPOSITE SIDE:

Sensory disturbances:

Some loss of pain sensations.


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Motor disturbances:

Nil or very slight.

Q-What are the functions of spinocerebellum?Enemurate

features of cerebellar diseases?

Ans:Functions:

i)-Planning and fine tunning of skeletal muscle contraction

ii)-Maintainance of posture and performance of voluntarymuscles

Features of cerebellar diseases:



iii)-Dysarthia

iv)-Intention tumor

SUPPLY 2006

Q-What is the nerve supply of the muscle spindle?How is it

stimulated?Enemurate its functions?

Nerve Supply of Muscle Spindle:

Motor Innervation:

*The end portions of the intrafusal fibers are innervated by


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gamma fibers

*Extrafusal fibers are innervated by alpha fibers

SENSORY INNERVATION:Two types of sensory endings are found in the

Central receptor area of the muscle spindle.These are:

Primary ending:

In the center of receptor area,a large sensory nerve fiber

encircles the central portion of each intrafusalfibers,formingthe so called primary ending or annulospiralending.This nerve

fiber is type Ia fiber.

Secondary Ending:

Usually one but sometimes 2 small nerve endings of type II

innervate the receptor region forming the secndary ending

STIMULATION:

i)-Lengthening of the whole muscle

ii)-Contraction of the end portions of the spindles of intra-

fusal fibers

Functions:

i)-Muscle spindle constituets a feedback device that operates

to maintain muscle length

ii)-Simplest menifestation of muscle spindle function is stretch


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reflex

iii)-Dynamic and static respons of muscle spindle performs

dampning function

iv)-Stabailizes body position during tense motor activity

v)-Maintains muscle tone

Q-Name motor areas in the cerebral cortex.Eumerate features

of the lower motor neuron lesion?

Ans:Motor areas of cerebral cortex:

i)-Primary motor cortex

ii)-Premotor cortex

iii)-Supplementory motor cortex

Features of Lower motor neuron lesion:i)-Flacid Paralysis

ii)-Areflexia

iii)-Abdominal and cremasteric reflexes are lost

iv)-Plantar reflex is normal

v)-Marked wasting of musclesvi)-Reaction of degeneration is present

vii)-Fasciculations

viii)-Small area of body is affected


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Q-What are the functions of thalamus?What are the features

of thalamic syndrome?

Ans:Functions:

i)-Thalamus is a great relay center

ii)-Center for crude sensations e.g crude touch and pressure

iii)-Important reflex center for emotional reactions eg rage is

mediated through thalamusiv)-It keeps cortex alert through its connections with

ascending reticular formation,thereby causing general

awakening.

Thalamic Syndrome:

It is a collection of symptoms resulting from damage of PLVnucleus of thalamus due to occlusion of thalamo-geniculate

artery.

*Effects occur on opposite side of body

*Loss of fine sensations

*Loss of crude sensations

*Exaggeration of pain sensations

*Hyptonia

*Chorea and athetosis


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ANNUAL 2007

Q-Name the motor areas in the cerebral cortex.What are the

functions of Broca,sarea?What is the effect of lesion in thisarea?

Ans: Motor Areas:

i)-Primary motor cortex

ii)-Supplementory motor cortex

iii)-Premotor cortex

Functions of Broca,s Area:

*Provides neural curcuitary for word formation

*Plans motor patterns for expressing individual

Words or even short phrases are initiated and executed

*Works in association with Wernicke,s area

*Causes the movement of muscles of speech in tongue,lips

and larynx.

Effect of lesion:

It causes motor aphasia.The person is capable of

deciding what he wants to say but cannot make the vocalsystem emit words

Q-Which neurotransmitters are released by the sympathetic

postganglionic fibers?Enumerate 8 effects of sympathetic


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Kidney Decreasd urine output and


Bladder

Detrusor

Trigone

Relaxed

Contracted

Penis Ejaculation

Fat cells lipolysis

Q-What is the motor and sensory loss at and below the level

of hemisection of the spinal cord.


On the Same side:Sensory Loss:


nerve root,post horn cells and lat and ventral spinothalamic

tracts crossing to the opposite side are all lost

Motor disturbances:


Damage to ant horn



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Sensory Loss:

Nil or very slightMotor Loss:


of same side


On the same side:



fasciculi gracilis and cuneatous which do not cross

*Pain,temperature and crude touch are not lost because





ON OPPOSITE SIDE:




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Motor disturbances:

Nil or very slight.

ANNUAL 2008

Q-Explain the functions of cerebrocerebellum.Enemurate 8

features of the cerebellar disease?

Ans:Functions of Cerebrocerebellum:

a)-Facilitates smooth and co-ordinated movements

b)-Ensures that force,direction and extent of movements areaccurate.

8 Features:


ii)-Past Pointingiii)-Dysdiadochokinesia

iv)-Dysarthia

v)-Intention tumor

vi)-Cerebellar Nystagmus

vii)-Hypotonia

viii)-Asthenia

Q-Enumerate 12 effects of sympathetic stimulation in the

body.Which neurotransmitter are released from preganglionic


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and postganglionic sympathetic nerve fibers?

Ans:Pre ganglionic fibers release acetylcholinePost ganglionic fibers releas Epinephrine and Nor-Epinephrine

ORGAN EFFECT

Heart

Muscle

Coronaries

Increased Rate

Increased Force of

contraction

Dilated(beta

2),Constricted(alpha)

Lungs

Bronchi

Blood VesselsDilated

Mildly Constricted

Gut

Lumen

Sphincter

Decreased peristalsis and

tone

Increased Tone

Liver

Gallbladder and bile ducts

Glucose released

Relaxed


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Kidney Decreasd urine output and


Bladder

Detrusor

Trigone

Relaxed

Contracted

Penis Ejaculation

Fat cells lipolysis

Basal metabolism Increased upto 100%

Adrenal medullary Secretion incresed

Mental activity incresed

Piloerector muscles contraction

Q-A middle aged man was hit by a motor car resulting into

fracture dislocation of vertebrae.Later he developed effects

indicating right sided hemisection of the spinal

cord.Enumerate the features below and at the level ofhemisection.


On the Same side:


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Sensory Loss:


nerve root,post horn cells and lat and ventral spinothalamictracts crossing

to the opposite side are all lost

Motor disturbances:


Damage to ant horn


Sensory Loss:

Nil or very slight

Motor Loss:Nil or slight due to damage to small direct pyramidal fibers

of same side


On the same side:Sensory Disturbances:


fasciculi gracilis and cuneatous which do not cross


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below the level of lesionMotor Disturbances :


ON OPPOSITE SIDE:


Some loss of pain sensations.Motor disturbances:

Nil or very slight.

Q-Mr.J of 58 years age with reting tremors of hand and lips

consulted his family doctor.On examination he was found to

have rigidity of limbs and expressionless face.He was having

short-stepped gait.

A)-From which disease Mr.J was suffering?

B)-What is the cause and mechanism of this disease

c)-Which drugs can be used to treat this disease?a)-Parkinsons,s disease

b)-Cause:

*Dopamine secreted in the caudate nucleus and putamen is


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an inhibitory transmitter,therefore the destruction of

dopaminergic neurons in the substantianigra of the

parkinsonian patient would allow the caudate nucleus andputamen to be overly excited leading to rigidity

*Some of the feedback curcuits might easily oscillate leading

to tremor.It is involuntary tremor

*Dopamine secretion in the limbic system,

Especially in the nucleus accumbens is often decreased alongwith its decrease in the basal ganglia.it might be the cause of

akinesia.

Q-What is the Speech area in the Cerebral Cortex?What do

you understand by Dyslexia?

Ans:Broca,s area is the speech area in the cerebralcortex.These are areas 44 and 45.

Dyslexia:

It is characterised by difficulty in learning to read fluently

and with accurate comprehension despite normal intelligence.

It is a learning disability.It includes reading

problems,spellingproblems,speech problems and dysgraphia

that makes a person difficult to master handwriting.


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Q-Enumerate effects of parasympathetic stimulation in the

body.Name the neurotransmitter in this nervous system?

Ans:*Chollinergic fibers release acetylcholine

*Adrenergic fibers release nor-epinephrine

ORGAN EFFECT

Lungs

Brochi

Blood vesselsConstricted

Dilated

Gut

LumenSphincter

Increased Peristalsis and

toneRelaxed

Liver

Gallbladder and bile ducts

Slight glycogen synthesis

Contracted

Bladder

Detrusor

TrigoneContracted

Relaxed


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Eye

Pupil

Ciliary Muscle

Contracted

Contracted

Penis erection

Glands

Nasal,lacrimal,parotid,

submandibular,gastric,pancreatic

Stimulation of copious

secretion

Annual 2009

Q-Enlist 8 functions of the body controlled by brainstem?

Ans:Functions

The brain stem is its own master because it provides many

special control functions,such as:

i)-Control of respiration

ii)-Control of cardiovascular system

iii)-Partial control of gastrointestinal functioniv)-Control of many stereotyped movements of the body

v)-Control of equilibrium

vi)-Control of eye-movements


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vii)-Serves as a way station for command signals from higher

centers

viii)-Provide support to the body against gravity

Q-A 60 year old man develops tremor in his hands and fingers

which become pronounced as he reaches for a glass of water

or points towards an object,He has difficulty maintaining his

balance?

A)-Which component of the nervous system is involved?B)-How are these tremors different fro other tremors due to

lesion of nervous system?

C)-Why this person has difficulty in maintaining

balance?

Ans:a)-Cerebellum

b)-These tremors differ from other tumor because these occur

when a person tries to do so voluntary action.Thats why these

are callled voluntary or intentional tumors.In case of basal

ganglia lesion these are involuntary tremors.

c)-Post Spinocerebellar fibers receive muscle joint info from

the muscle spindles,tendon organs and joint receptors of the

trunk and lower limbs.This info concerning tension of muscle


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tendons and the movements of muscles and joints is used by

the cerebellum in the

Maintainance of posture.The ant spinocerebellar tract

provides the same info from the upper and lower

limbs.Cuneocerebellar tracts provide info of muscle joint.In

cerebellar lesion the cerebellum cannot comprehend these

info and resultss in loss of balance

ANNUAL 2010

Q-A boxer at the age of 45 years was diagnosed to be

suffering from Parkinson,s disease.

A)-What are the characteristics of this disease?

b)-Suggest possible treatments?

Ans:Cause:

*Dopamine secreted in the caudate nucleus and putamen is

an inhibitory transmitter,therefore the destruction of

dopaminergic neurons in the substantianigra of the

parkinsonian patient would allow the caudate nucleus and

putamen to be overly excited leading to rigidity*Some of the feedback curcuits might easily oscillate leading

to tremor.It is involuntary tremor

*Dopamine secretion in the limbic system, Especially in the


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nucleus accumbens is often decreased along with its decrease

in the basal ganglia.it might be the cause of akinesia.

B)-Treatment:i)-L-Dopa

ii)-L-Deprenyl

iii)-transplanted fetal dopamine cells

iv)-By Destroying part of the feedback circuitry

Q-a)-What are the various types of pain?

B)-Explain the mechanism of referred pain with the help of

diagram?

Ans:Types of pain:

FAST PAIN:

*Very Short acting*Mostly caused by thermal and mechanical stimuli

*Carried by A delta fibers via neospinathalamic pathway

*Localization of pain is good

*Velocity=6-30 /sec

*Neurotransmitter is glutamate.Slow Pain:

*Long acting

*Mostly caused by chemical stimuli


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*Carried by C fibers via paleospinothamlamic pathway

*Localization of pain is poor

*Velocity=0.5 2 m/sec*Neurotransmitter is substance P

Ans b):Mechanism of reffered pain:

Branches of visceral pain fibers synapse synapse in spinal cord

on the same second order neurons(1 and 2) that reeceive pain

signals from skin.When the visceral pain fibers arestimulated,pain signals from the viscera are conducted

through at least some of the same neuron that conduct pain

signals from the skin and person has feeling that the

sensation originate in the skin itself

Q-Give the structure and functions of muscle spindle?Ans:Structure:

Muscle spindle is built around 3 12 tiny intrafusal fibers that

are pointed at their ends and attached to the glycocalyx of

the surrounding large extrafusal skeletal muscle fibers.

Each intrafusal fiber is a tiny skeletal muscle

fiber.However,the central region of each of these fibers that

is,the area midway between the 2 ends has few or no actin

and myosin


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Therefore,this central portion does not contract when the

ends do.Instead ,it functuins as a sensory receptor.The end

portions that do contract are excited by gamma motor nervefibers that originate from small type A gamma motor neurons

in the ant horns of the spinal cord.Extrafusaled by fibers are

innervated by alpha fibrers

Functions:

i)-Muscle spindle constituets a feedback device that operatesto maintain muscle length

ii)-Simplest menifestation of muscle spindle function is stretch

reflex

iii)-Dynamic and static respons of muscle spindle performs

dampning function

iv)-Stabailizes body position during tense motor activity

v)-Maintains muscle tone

Annual 2012

Q- We experience different modalities of sensations

(e.gpain,touchetc) although the nerve fibers

transmitonlyimpulses.How is it that different nerve fibers

transmit different modalities of sensation?Give an example to

explain?


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Ans:Each of the principle type of sensation that we can

experience-pain,touch,sight,sound and so forth-is called a

modality of sensation.Each nerve tract terminates at a specific point in

The central nervous system, and the type of sensation felt

when a nerve fiber is stimulated is deteremined by the point

in the nervous system to which the fiber leads.Forexample,if a

pain fiber is stimulated ,the person perceives pain regardlessof what type of stimulus excites the fiber.The stimulus can be

electricity,overheating of the fiber,crushing of the fiber,or

stimulus of the pain nerve ending by damage to the tissue

cells.In all these instances the person perceives pain.Likewise,if

a touch fiber is stimulated by electrical excitation of a touch

receptor or in

Other way,the person perceives touch because touch fibers

lead to specific touch areas in the brain,fibers from the ear

terminate in the auditory areas of the brain,and the

temperature fibers terminate in the temperature areas.

The specifity of nerve fibers for transmitting only one

modality of sesation is called labeled line principle.


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Q-A 67 yearsold man visits his neurologist and complains that

it is extremely difficult for him to stand up sitting position or

start walking from standing position.He also complains oftremulous movements of the fingerswhuch disappear when

he starts doing something.

a)-what is the condtion called?

B)What is the lesion/damage located?

C)-What is the speculated cause of difficulty this man

experiences in intitiating a movement?

Ans: a)-Parkinson,s disease

b)-Basal ganglia

The akinesia that occurs in Parkinson,s disease is often much

more distressing to the patient than are the symptoms of

muscle rigidity and tremor,because to perform even the

simplest movement in severe parkinsonism,the person must

exert the highest degree of conc.The cause of akinesia is still

speculative.However,dopamine secreted in the limbic

system,especially in the nucleus accumbens,is often decreased

along with its decrease in the basal ganglia.It has beensuggested this might reduce the psychic drive

For motor activity so greatly that akinesia results


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Q-A man of 45 years received a gun short on his back.He

developed right sided hemisection of the spinal cord.

A)-Give the features below,above and at the level of lesion?

B)-What is Brown-Sequard Syndrome?


On the Same side:Sensory Loss:


nerve root,post horn cells

and lat and ventral spinothalamic tracts crossing

to the opposite side are all lostMotor disturbances:


Damage to ant horn


Sensory Loss:

Nil or very slight

Motor Loss:


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of same side


On the same side:

Sensory Loss:

On the same side:


*Fine touch and proprioception are lost due to damage tofasciculi gracilis and cuneatous which do not cross






ON OPPOSITE SIDE:



Motor disturbances:

Nil or very slight.

EFFECT ABOVE LEVEL OF LESION:

On Same Side:


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There is a narrow zone of hyperaesthesia or hypersensitive to

touch,pain and thermal stimuli due to irritation of upper cut

ends of damaged fibers.

Opposite side:

Hyperaesthesia may be referred.

B)-In Brown sequard syndrome there is complete hemisection

of spinal cord.Its features are

*Ipsilateral lower motor neuron paralysis in the segment oflesion and muscular atrophy

*Ipsilateral spastic paralysis below the level of lesion

*Ipisilateral band of cutaneous anasthesia in the segment of

lesion.

*Ipsilateral loss of tactile discrimination, and of

Vibratory and proprioceptive sensations below the level of

lesion.

*Contralateral loss of pain and temp sensations below the

level of lesion

*Contralateral but not complete loss of tactile sensation below

the level of the lesion

Q-What are the functions of spinocerebellum?Enemurate

features of cerebellar diseases?


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Ans:Functions:

i)-Planning and fine tunning of skeletal muscle contractionii)-Maintainance of posture and performance of voluntary

muscles

Features of cerebellar diseases:



iii)-Dysarthia

iv)-Intention tumor

PREPARED BY

AHSAN SARWARLahore medical and dental college

Gastrointestinal Physiology

Question No: 1 What do you know about pharyngeal stage of

swallowing along with its nervous control? (Supplementary 2004)

Answer: Chapter 63 (Guyton)

SWALLOWING


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2

ndStage (Pharyngeal Stage)

1-Bolus stimulates the epithelial swallowing receptor areasaround opening of pharynx.

2-Soft palate is pulled upwards.3-The palatopharyngeal folds and vocal cords are approximated.4-Epiglottis swings backward over the opening of larynx.5-Upward movement of larynx and opening of the upper

oesophagealsphinchter.

6-Contraction of pharyngeal muscles and propulsion of food byperistalsis into oesophagus.

Nervous Control:

Sensory: Sensory portions of trigeminal and glossoharyngeal nerves

into the medulla, either into or closely associated with the tractus

solitaries.

Areas in the medulla and lower pons are called swallowing centre.

Motor: 5th

,9th

,10th

and 12th

cranial nerves and a few cervical nerves.

Question No: 2 Write a short note on :

A)Pharyngeal stage of swallowingB)Actions of cholecystokinin (Annual 2005)Answer:


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A)Answer No 1 above.B)1- stimulates pancreatic enzyme secretion.

2- stimulates pancreatic bicarbonate secretion.3- causes gallbladder contraction.

4- growth of exocrine pancreas.

5-inhibits gastric emptying.6-Inhibits appetite.

Question No: 3 What events occur during the pharyngealstage of swallowing? Name the nerves that control this stage?

(Annual 2005)

Answer: Answer No 1 above.

Question No:4 How is gastric emptying regulated? (annual

2006)

Answer: Chapter no 63(guyton)

Gastric factors that promote emptying:

1-Effect of gastric food volume on rate of emptying2-Effect of the hormone gastrin on stomach emptyingDuodenal factors that inhibit stomach emptying:

1-Inhibitory effect of enterogastric nervous reflexes fromduodenum:

2- Factors initiating enterogastric reflexes: Degree of distention of duodenum


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Presence of any irritation Acidity and osmolality of the chyme Presence of certain breakdown products in chyme

3-Hormonal feedback from duodenum: CCK Secretin GIP (check the book for their detailed functions)

Question No: 5 What are the movements of small intestine?

(supplementary 2006)

Answer: Chapter 63(guyton)

Movements:

Two types:

1-Mixing contractions(segmentation contractions): Contractions cause segmentation of small intestine

Chop the chyme 2-3 times per minute Frequency is determined by the electrical slow waves

normally it is 12/minute in duodenum and jejunum and

in ileum 8-9/minute.

Contractions can be blocked by atropine


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2-Propulsive movements:

Peristalsis in small intestine: velocity is 0.5-2cm/sec Control of peristalsis by nervous and hormonal signals1-Stretch of duodenal wall

2-Gastroenteric reflex3-Gastrin, cck, insulin, motilin and serotonin enhance

motility.

4-Secretin and glucagon inhibit motilityQuestion No: 6 List the motor functions of stomach? Wha arehunger contractions? (annual 2006)

Answer: Chapter 63(guyton)

Motor Functions:

1-Storage function of somach: Vagovagal reflex reduces the tone in the muscular wall of

body of stomach.

Stomach can store 0.8 1.5 litres of food.2-Mixing and propulsion of food- Basic electrical rhythm of

stomach wall:

Gastric juices secreted by gastric glands Mixing waves begin in the mid two upper portions of

stomach and move towards the antrum

These waves are initiated by basic electrical rhythm


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Powerful constrictor rings force the antral contents

towards pylorus

Retropulsion3-Gastric emptying:Answer no 4 above

Hunger Contractions:

* Contractions that occur when the stomach has been

empty for several hours.* Duration 2-3 minutes.

* Intense in young people and those having low blood sugar

levels.

* Sometimes causes mild pain called hunger pangs

* Donotbegin until 12-24 hours after last ingestion.

Question No: 7 What type of movements occur in small

intestine when it becomes distended with chyme? (annual

2007)

Answer: Answer no 5 above.

Question No: 8 Name the stages of deglutition? Whichchanges will occur during second stage? (supplementary

2007)

Answer: Stages:

1-Voluntary stage of swallowing


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2-Pharyngeal stage of swallowing3-Oesophageal stage of swallowing

Question No: 9 what is enteric nervous system?

which defect in enteric nervous system leads to

oesphagealachlasia?

Answer: chapter 62(guyton)Composed mainly of two plexus:

1-Myenteric or auerbachs plexus: Controls G.I.T movements Present between the inner circular and outer longitudinal

muscle layers

2-Submucosal or meissners plexus:

Controls G.I.T secretions and local blood flow. Present in the submucosa

Achlasia:

Oesphagealsphinchter fails to relax during swallowing Damage in neural network of myenteric plexus in lower

two thirds of oesophagus

Myenteric plexus loses its ability to cause receptiverelaxation of oesophagealsphinchter.


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Question No: 10 list the functions of stomach? Give

factors which increase the rate of emptying of stomach?

(annual 2008)

Answer: Answer no 6 above for functions.

Answer no 4 above for factors.

Gastric factors promote stomach emptying.

Question no: 11 Compare the effects of sympathetic andparasympathetic stimulation on G.I.T (supplementary

2008)

Answer: chapter 62(guyton)

Autonomic control:

Parasympathetic:

Increases G.I.T activity Cranial portion by vagus nerve and sacral portion by

2nd

,3rd

,and 4th

pelvic splanchnic nerves. Postganglionic

neurons are located in myenteric and submucosal plexus.

Enhances the activity of G.I.T functions.

Extensive near to oral cavity and anus.

Sympathetic:

Inhibits G.I.T activity.


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Fibres originate in spinal cord between segments t5-l2.

Some fibres enter sympathetic chains and then pass to

celiac ganglion ormyenteric ganglion. Most of the post ganglionic neurons

are in these ganglion.

Innervates all the G.I.T Secrete epinephrine and nor epinephrine

Question no 12: give five differences betweenobstructive and hemolytic jaundice?

Answers:

Chapter no 70(guyton)

1-Hemolytic jaundice is caused by hemolysis of RBCswhereas obstructive jaundice is caused by obstructionof bile duct or liver diseases.

2-In hemolytic jaundice unconjugated bilirubin isincreased whereas in obstructive conjugated bilirubin

is increased.

3-URobilinogen is increased in hemolytic jaundice anddecreased in obstructive jaundice.

4-Urine color is normal in hemolytic but it is dark inobstructive jaundice due to conjugated bilirubin.

5-Stool color Is normal in hemolytic jaundice but pale inobstructive jaundice.


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6-Splenomegaly is present in hemolytic jaundice but

absent in obstructive jaundice.

Question no:13

A)Enumerate the factors that regulate gastric emptying?B)Enumerate the factors that can excite enterogastric

reflexes from duodenum?

Answer: A) answer no 4 above for gastric emptying

B)Factors initiating enterogastric reflexes:

Degree of distention of duodenum Presence of any irritation Acidity and osmolality of the chyme Presence of certain breakdown products in chyme

Question no 14: A person is diagnosed to have a gastric ulcer on

endoscopy.

a)What is pathophysiology of this disease?b)How the intestine normally handles the excessive acidity in

chyme?

Answer: A) chapter 66(guyton)

Caused by:

Digestive action of gastric juice or uuper small intestinesecretions


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Imbalance between rate of secretion of gastric juice and

degree of protection afforded by mucosal barrier and

neutralization of gastric acid by duodenal juices. Excessive secretion of acid and pepsin Bacterial infection by helicobacter pylori Smoking Alcohol Aspirin

B)alkalinity of the small intestine secretion

Large quantity of sodium bicarbonate in pancreatic secretion

neutralizing HCL, inactivating pepsin and preventing digestion of

mucosa

Large amounts of bicarbonate ions by the secretion of brunnersglands and in bile

Acidic chyme entering duodenum inhibits gastric secretion and

peristalsis in stomach

Presence of acid in small intestine stimulates secretin secretion

which in turn stimulates bicarbonate secretion.

PREPARED BY

SALEHA RASHID & ZAINUB ARIF

FMH college of medicine & dentistry


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ENDOCRINOLOGYQ:How does cyclic Amp mediate hormonal action at cellular level?

which hormones obey the cyclic-Amp mechanism ? (ANNUAL

Paper 2004)

Ans:Adenylyl CyclasecAMP Second

Messenger System

Binding of the hormones with the receptor

allows coupling of the receptor to a G protein ----->

G protein stimulates the adenylyl cyclasecAMP

system, a membrane-bound enzyme---->Gs protein then catalyzes

the conversion of a small amount of cytoplasmic

adenosine triphosphate (ATP) into cAMP inside the

cell.-----> This then activates cAMP-dependent protein

kinase, which phosphorylates specific proteins in the

cell, triggering biochemical reactions that ultimately

lead to the cells response to the hormone.

Some Hormones That Use the Adenylyl CyclasecAMPSecond Messenger System

Adrenocorticotropic hormone (ACTH)

Angiotensin II (epithelial cells)


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Calcitonin

Catecholamines (b receptors)

Corticotropin-releasing hormone (CRH)

Follicle-stimulating hormone (FSH)

Glucagon

Human chorionic gonadotropin (HCG)

Luteinizing hormone (LH)

Parathyroid hormone (PTH)

Secretin

Somatostatin

Thyroid-stimulating hormone (TSH)

Vasopressin (V2 receptor, epithelial cells)

Q: Differentiate between the etiology and features of Dwarfism

and cretinism ? (ANNUAL Paper 2004 & 2006)

Ans: Dwarfism

=>dwarfism result from generalized

deficiency of anterior pituitary secretion (panhypopituitarism)

during childhood.

=>all the physical parts of the body develop in appropriate

proportionto one another

=>dwarf does not pass through puberty

=>mental level is normal


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=>African pygmy and the Lvi-Lorain

dwarf are its types

Cretinism

=>Cretinism is caused by extreme hypothyroidism during

fetal life, infancy or childhood

=>disproportionate rate of growth,

=>obese, stocky, and short appearance.

tongue becomes so that it obstructs swallowing.

=>mental retardation

=>congenital cretinism and endemic cretinism are its types

Q:Explain various steps involved in the biosynthesis of Thyroid

hormones?(ANNUAL Paper 2005 & supplementary 2006)

Ans:

=>Formation and Secretion of Thyroglobulin by the Thyroid Cells

=>Oxidation of the Ion

The oxidation of iodine is promoted by the enzymeperoxidase


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and its accompanying hydrogen peroxide, which

provide a potent system capable of oxidizing iodides.

=>Iodination of Tyrosine and Formation of the Thyroid HormonesOrganification of Thyroglobulin

oxidized iodine is associated with an iodinaseenzyme iodine binds

with about one sixth of the tyrosine amino acids within the

thyroglobulin molecule.Tyrosine is first iodized to

monoiodotyrosineand then to diiodotyrosinewhic coupled to form

the thyroxine and triidotyrosin.

=>Storage of Thyroglobulin

Q:What are different second messengers mechanisms of

hormonal actions?(ANNUAL Paper 2005)

Ans:AdenylylCyclasecAMP Second

Messenger System

The Cell Membrane Phospholipid Second

Messenger System

Calcium-Calmodulin SecondMessenger Syste

GMP second messenger system

prostaglandins


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Q:Name the hormones secreted from the thyroid gland. Explain

mechanism of action of steroid hormones? (ANNUAL Paper 2006)

Ans: thyroxineandtriiodothyronine, commonly called T4 and T3, respectively.

Calcitonin

Mechanism of action of steroid hormones:

=>steroid hormones, exerts its effects

by first interacting with intracellular receptors in target

cells.

. =>They can easily diffuse through the cell membrane. Once insidethe cell,

they binds with protein receptor in the cytoplasm,

and the hormone-receptor complex then interacts with

specific regulatory DNA sequences, called glucocorticoid or

minerilocorticoid

response elements, to induce or repress gene transcription.

=>Other proteins in the cell, called transcription

factors, are also necessary for the hormone-receptor

complex to interact appropriately.

Q:Enumerate:

a) Features of Cushing's syndrome

b) Features of Tetany (supplementary 2006)

Ans; Features of cushing's syndrome:


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hypersecretion of adrenal cortex.

-emotional disturbance

-Enlarged sellaturcica

-moon face

-oteoporosis

-cardiac hypertrophy

-buffalo hump

-obesity

-Amenorrhea

-muscle weakness

-purpura

-skin ulcers

Features of tetany:

low ECF calcium

-threshold for action potential is lowered

-Nervous system is in more excited state

-gait abnormality (scissor gait , spastic gait)

-movement disorders


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-lack of cordination

-joint locking

Q: A young man reported to his family doctor with the complaints

of palpitation, loss of weight in spite of increased appetite and

intolerance to heat. On examination he was having pulse rate

110/min, his eyes were prominent and there was swelling on the

anterior side of the neck.

a) From which disease he was suffering ?

b) Which investigations will you advise?

c)What is the cause of the disease? (Annual paper 2007)

Ans: a)Hyperthyroidism

b)The most accurate diagnostic test is

direct measurement of the concentration of free thyroxine

(and sometimes triiodothyronine) in the plasma. other tests

include

1. The basal metabolic rate which will be high in this case.


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2. The concentration of TSH in the plasma. TSH is completely

suppressed by the

large amounts of circulating thyroxine and

triiodothyronine so there is almost no plasma

TSH.

3. The concentration of TSI is measured by

radioimmunoassay. This is usually high in

thyrotoxicosis but low in thyroid adenoma

.

C)Hyperthyroidpateints have certain substances in the blood.These substances

are immunoglobulin antibodies that bind with the

same membrane receptors that bind TSH. They induce

continual activation of the cAMP system of the cells,

with resultant development of hyperthyroidism. These

antibodies are called thyroid-stimulating immunoglobulin

and are designated TSI.Throid adenoma also leads to hyperthyroidism.

Q: What are physiological actions of cortisol on proteins and

carbohydrate metabolism? Enumerate six features of Cushing's

syndrome? {Annual paper 2007 , 2008 (action on proteins) &

supplementary 2008 ( action on carbohydrates)}

Ans: Effect on carbohydrate metabolism:

=>increase gluconeogenesis

-Cortisol increases the enzymes required to convert

amino acids into glucose in the liver cells


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-Cortisol causes mobilization of amino acids from

theextrahepatic tissues mainly from muscle. as the result more

amino acids are avialable for gluconeogenesis.

=>Decreased Glucose Utilization by Cells.

Effect on protein metabolism:

=>Reduction in Cellular Protein.

This is caused by both

decreased protein synthesis and increased catabolismof protein already in the cells

=>Cortisol Increases Liver and Plasma Proteins.

It is believed that this results from a possible effect of cortisol to

enhance amino acid transport into liver and to enhance the

liver enzymes required for protein synthesis

=>Increased Blood Amino Acids, Diminished Transport of Amino

Acids into Extrahepatic Cells, and Enhanced Transport into

Hepatic Cells

Q:What are physiological actions of cortisol on proteins ?How is

cortisol secretion regulated ? (Annual paper 2008)

Ans; Regulation of cortisol secretion:

fig 77-6

=>ACTH Stimulates Cortisol Secretion.


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An important releasing factor controls ACTH secretion. This is

called corticotropin-

releasing factor(CRF). It is secreted into the

primary capillary plexus of the hypophysial portal

system in the median eminence of the hypothalamus

and then carried to the anterior pituitary gland, where

it induces ACTH secretion.

=>ACTH Activates Adrenocortical Cells to Produce Steroids by

Increasing Cyclic Adenosine Monophosphate (cAMP).

The most important of all the ACTH-stimulated

steps for controlling adrenocortical secretion is activation

of the enzymeprotein kinase A, which causes

initial conversion of cholesterol to pregnenolone. This

initial conversion is the rate-limiting step for all the

adrenocortical hormones.

Q:A young female consulted her family physician . She

complained of frequent muscle spasms and numbness of arms

and legs. Her plasma calcium was 6.5mg/dl.

a) From which condition was she suffering ?

b) was her plasma calcium normal?

c)What was the mechanism of her frequent muscle spasms andnumbness? (Annual paper 2008)

Ans: a) Tetany

b) no , her plasma calcium level was lower. normal value is 9.8 to


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11.5 mg/dl.

c) Her neurons are over excited , threshold for action potential is

decreased , even little sodium influx leads to sudden muscle

contraction ( muscle spasms ).

Q: A boy of 10 years was brought by his father to a medical

specialist. The boy because of retarded growth appeared to be of

4-5 years. During talking the boy answered the question

intelligently. His body parts were proportionate but of smaller

size:

a) Fom which disorder the boy was suffering?

b) what was the cause of this disorder?

c)what are different types of this disorder? ( supplementary 2008)

Ans; a) Dwarfisim

b) insufficient growth hormone produced by the anterior pitutiary

hormone.

c) African pygmy ,Lvi-Lorain dwarfism .

Q: a)What are physiological actions of cortisol on carbohydrates?

b) what is the difference between Cushing's syndrome and

Cushing's disease?( supplementary 2008)

Ans; a) see above questions


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b) Hypersecretion by the adrenal cortex causes a complex

cascade of hormone effects called Cushings syndrome

When Cushings syndrome is secondaryto excess secretion of ACTH by the anterior

pituitary, this is referred to as Cushings disease

Q:Name the hormones of anterior pitutiary gland ? What are

somatomedians? (annual paper 2009)

Ans;Growth hormone

Adrenocorticotropic hormone

Thyroid-stimulating hormone

Gonadotropes Follicle-stimulating

(FSH)

Luteinizing hormone (LH)

prolactinb) Somatomedians are insulin like growth factors though which

growth hormone takes its action and perform different functions

like formation of proteins.

Q: A 45 year old female give the month history of fatigue , hunger

and thirst almost all the time . there is increased frequency of

micturation as well and the complaints have steadily worsened

over the last two months. lab tests reveal:

a)what is the lady suffering from?

b) what is the physiological reason of increased frequency of


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micturation?

c) why is she hungry all the time ?

d)why is she always thirsty ?

e) what are different types to this disorder? ( Annual paper 2009)

a. diabetes mellitus (type 2)

b. increased osmotic effect of glucose decreases tubular

reabsorptionc. impaired glucose uptake by cells for energy.

d. increased blood osmolarity stimulates the hypothalamus

osmotic receptors

e. type 1 and type 2

Q:a) what are the endocrine functions of pancrease?

b) Enlist the factors which increase insulin secretion?( Annual

paper 2010)

Ans: alpha cells glucagon

beta cells insulin

b. Increased blood glucose

Increased blood free fatty acids

Increased blood amino acids

Gastrointestinal hormones


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(gastrin, cholecystokinin, secretin,

gastric inhibitory peptide)

Glucagon, growth hormone,

cortisol

Parasympathetic stimulation;

acetylcholine

b-Adrenergic stimulation

Insulin resistance; obesity

Sulfonylurea drugs (glyburide,

tolbutamide)

Q: Give pathophysiology and features of 43 year old lady who is

diagnosed as a case of toxic goiter?( Annual paper 2010)

Symptoms of Hyperthyroidism

The symptoms of hyperthyroidism are obvious from the

preceding discussion of the physiology of the thyroid

hormones: (1) a high state of excitability, (2) intoleranceto heat, (3) increased sweating, (4) mild to extreme

weight loss (sometimes as much as 100 pounds), (5)

varying degrees of diarrhea, (6) muscle weakness, (7)

nervousness or other psychic disorders, (8) extreme

fatigue but inability to sleep, and (9) tremor of the

hands.

Exophthalmos

Q:How 24 hour blood glucose is regulated in normal person ?(

Annual paper 2011)

Growth Hormone Decreases


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Carbohydrate Utilization

Growth hormone causes multiple effects that

influence carbohydrate metabolism, including (1)

decreased glucose uptake in tissues such as skeletal

muscle and fat, (2) increased glucose production by

the liver, and (3) increased insulin secretion.

Glucose absorption

Gluconeogenesis

Glycogenolysis

insulin lowers glucagon increases

Q:Enumerate the specific effects of thyroid stimulating hormone

(TSH) on thyroid gland?( Annual paper 2011)

Increased proteolysis of the thyroglobulin that

has already been stored in the follicles, with

resultant release of the thyroid hormones intothe circulating blood and diminishment of the

follicular substance itself

2. Increased activity of the iodide pump, which

increases the rate of iodide trapping in the

glandular cells, sometimes increasing the ratio of

intracellular to extracellular iodide concentration

in the glandular substance to as much as eighttimes normal

3. Increased iodination of tyrosine to form the

thyroid hormones

4. Increased size and increased secretory activity of


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the thyroid cells

5. Increased number of thyroid cells plus a change

from cuboidal to columnar cells and much

infolding of the thyroid epithelium into the

follicles

In summary, TSH increases all the known secretory

activities of the thyroid glandular cells.

PREPARED BY:

Waqar Sharif

CMH Medical College

REPRODUCTIONQ1. enumerate hormones that take part in lactation. explain the

action of prolactin. (annual 2004)

A. prolactin, oxytocin, estrogen and progesterone.production of

milk in breasts and breast enlargement

Q2. what are stages of spermatogenesis? name the hormones

which control sperm formation. (annual 2005)

A. spermatocytogenesis


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spermatogonium a to spermatogaonia b to primary spermatocyte

to secondary spermatocyte via meiosis to spermatid

spermiogenesis

spermatid to sperm

testosterone, Lh, Fsh, Gh, estradiol

Q3. explain the phases of endometrial cycle. (annual 2006)A. proliferative phase

increase in thickness due to estrogen

secretory phase

progesterone causes secretion

menstrual phase

estrogen and progesterone lower. Lhncrease

Q4. give a summary of actions of estrogens. (supp 2006)

thickens vagina

increase external genitalia size

increase in uerine size, glands, vascularity


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inhibitLh and Fsh

secondary sexual characteristics

Q5. enumerate functions of testosterone during fetal life.

whatare functions of sertolli cells. (annual 207)

external genitalia and male genital organs increase in size

suppreses formation of female genitaliadescent of testes

sertolli cells offer nutririon, support, spermatogenesis,

spermiogenesis, mullerian inhibitory factor, estradiol, inhibin

Q6. compare the physiological actions of estrogens and

progesterones on the a. uterus b. breasts. (annual 2008)

estrogen increase uterus size, glands and increase breast size and

glandular tissue

progesterone causes secretory phase, decreases contraction and

growth of lobules and alveoli of breast causing its swelling

Q7. a. when a baby suckles a mothers breast, how is milk ejected

out into babys mouth. b. why in more than 50 % lactating women,


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the lactating cycle is inhibited? (supp 2008)

babysuckels nipples - sensory impulses - hypothalamus - oxytocin

and prolactin - contraction of myoepithelium - milk ejection n let

down

inhibited because suckling - hypothalamus - suppresesLhrh -

suppress FshLh - ovarian cycle suppressed

Q8. briefly describe the changes that occur during the

capacitation of spermatozoa. (annual 2009)

acrosome reaction

zona reaction

Q9. which hormonal factors cause increase contractility of uterine

muscle at the end of pregnancy? (annual 2010)

oxytocin, estrogen, prostaglandins, cortisol

Q10. give hormonal influence on female breasts duringadolescence, pregnancy and lactation. (annual 2011)

estrogenfr ductal system

progesteronefr glandular system


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estrogen , progesterone, Gh, prolactin, cortisol, insulin

prepared by

Waqar Sharif

CMH Medical College

RENAL PHYSIOLOGYQ: what is filtration pressure? How does auto

regulation of glomerular filtration rate (GFR) occur?

Answer: Filtration Pressure: the net driving force

which pushes fluid into tissue spaces and out of

vascular sites; the net result between capillary

osmotic pressure and intravascular hydrostatic

pressure. For example-it occurs in the kidneys for

the filtration purposes and in the capillaries where

starling forces act together to determine the

direction of going of fluid either into the capillary orout of it.

Auto regulation of glomerular filtration rate:

1. Role of Tubuloglomerular Feedback

In Auto regulation of GFR: The Tubuloglomerular


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feedback mechanism has two components that act

together to control GFR:

(1) An afferent arteriolar feedback mechanism and

(2) an efferent arteriolar feedback mechanism.These feedback mechanisms depend on special

delivery to the macula densa in these circumstances

anatomical arrangements of the juxtaglomerular

complex. The juxtaglomerular complex consists of

maculadensa cells in the initial portion of the distal

tubule and juxtaglomerular cells in the walls of the

afferent and efferent arterioles. The macula densais a specialized group of epithelial cells in the distal

tubules that comes in close contact with the

afferent and efferent arterioles. The macula densa

cells contain Golgi apparatus, which are intracellular

secretory organelles directed toward the arterioles,

suggesting that these cells may be secreting a

substance toward the arterioles. Tubuloglomerular

feedbackmediated renal vasoconstriction thatoccurs in response to the increased sodium chloride

2. Myogenic Auto regulation of Renal GFR: Stretch

Of the vascular wall allows increased movement of

Calcium ions from the extracellular fluid into the

cells, causing them to contract. This contraction

prevents over distention of the vessel and at the

same time, by raising vascular resistance, helps


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prevent excessive increases in renal blood flow and

GFR when arterial pressure increases

3. High Protein Intake and Increased Blood

Glucose: following: A high-protein meal increases

the release of amino acids into the blood, which are

reabsorbed in the proximal tubule. Because amino

acids and sodium are reabsorbed together by the

proximal tubules, increased amino acid

reabsorption also stimulates sodium reabsorption in

the proximal tubules. This decreases sodium

delivery to the macula densa, which elicits a

Tubuloglomerular feedbackmediated decrease

In resistance of the afferent arterioles. The

decreased afferent arteriolar resistance then raises

renal blood flow and GFR. This increased GFR allows

sodium excretion to be maintained at a nearly

normal level while increasing the excretion of the

waste products of protein metabolism, such as

urea.A similar mechanism may also explain the


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marked increases in renal blood flow and GFR that

occur with large increases in blood glucose levels in

uncontrolled diabetes mellitus. Because glucose,

like some of the amino acids, is also reabsorbed

along with sodium in the proximal tubule, increased

glucose delivery to the tubules causes them to

reabsorb excess sodium along with glucose. This, in

turn, decreases delivery of sodium chloride to the

maculadensa, activating a Tubuloglomerular

feedbackmediated dilation of the afferent

Arterioles and subsequent increases in renal blood

Flow and GFR.

Q: Compare and contrast metabolic acidosis occur

due to lesions?

A:1. Lesion occur in the Adrenal Cortex: it causes

hypo function of the adrenal cortex resulting in the

Addisons disease .causing metabolic acidosis due to

decreased production of Aldosterone which is

important for the conservation of Na and HCO3.


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2. Lesion occur in the G.I.T: in diarrhea the intestine

fails to absorb bicarbonate ions in addition to other

ions causing metabolic acidosis.

3. Lesion of the renal tubules: the renal tubules

fails to save the bicarbonate ions a condition which

is related to Fanconis syndrome.

Q. EXPLAIN COUNTER CURRENT MULTIPLIER MECHANISM FOR

CONCENTRATION OF URINE?

ANSWER

There are three steps

A.HYPEROSMOLALITY OF THE MADULLARY INTRSTITIAL FLUIDThis is achieved by following mechanisms

First the principle cause of greatly increased medullary osmolality is

active transport of Na+ and Cl- into medullary interstitium from thick

portion of ascending limb of loop of henle.

Second smaller quantities of ions are also transported into the

medullary interstitial fluid from the collecting duct for example

chloride ions are passively absorbed along with sodium ions

In presence of ADH water is reabsorbed from collecting duct

increasing urea concentration in collecting duct so urea diffuses from

collecting duct into medullary interstitium


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ANSWER

Renal clearance of a substance is the volume of plasma that is completely

cleared of a substance by the kidney per unit time

Cs = Us * V / Ps

Cs = clearance rate of a substance

Us = urine concentration of a substance

V = urine flow rate

MEASUREMENT OF GFR

We give the patient a constant supply of inuline because it is neither

reabsorbed nor secreted in tubule. The urine secreted in a known time is

measured in volume from which urine formed per minute can be

calculated. Concentration of inuline in urine is also measured which gives us

a measurement of GFR

GFR = Us * V / Ps

Creatinine clearance is also used to measure GFR accurately it is easier than

inuline clearance because creatinine is already present in body fluids

GFR = Ccr = Ucr * V / Pcr

Ccr = creatinine clearance

Ucr * V = creatinine excretion

Pcr = plasma creatinine concentration

MEASUREMENT OF RENAL PLASMA FLOW


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ducts to water, thereby allowing these tubular

segments to avidly reabsorb water, and

(2) a high osmolarity of the renal medullary

interstitial fluid, which provides the osmotic

gradient necessary for water reabsorption to

occur in the presence of high levels of ADH.

The renal medullary interstitium surrounding

the collecting ducts normally is very

hyperosmotic, so that when ADH levels are

high, water moves through the tubular

membrane by osmosis into the renal

interstitium; from there it is carried away by

the vasa recta back into the blood. Thus, the

urine concentrating ability is limited by the

level of ADH and by the Degree of

hyperosmolarity of the renal medulla. We

discuss the factors that control ADH secretion

later, but for now, what is the process by which

renal medullary interstitial fluid becomes


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hyperosmotic? This process involves the

operation of the countercurrent mechanism.

The countercurrent mechanism depends on the

special anatomical arrangement of the loops of

Henle and the vasa recta, the specialized

peritubular capillaries of the renal medulla. In

the human, about 25 percent of the nephrons

arejuxtamedullary nephrons, with loops of

Henle and vasa recta that go deeply into the

medulla before returning to the cortex. Some

of the loops of Henle dip all the way to the tips

of the renal papillae that project from the

medulla into the renal pelvis. Paralleling the

long loops of Henle are the vasa recta, which

also loop down into the medulla before

returning to the renal cortex. And finally, the

collecting ducts, which carry urine through the

hyperosmotic renal medulla before it is

excreted, also play a critical role in the


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countercurrent mechanism.

Q: Explain Micturition Reflex, What is Atonic

Bladder?

Answer: (Referring again to Figure in Guyton

and halls page no.309)as the Bladder fills, many

superimposed micturition contractions begin to

appear, as shown by the dashed spikes. They

are the result of a stretch reflex initiated by

sensory stretch receptors in the bladder wall,

especially by the receptors in the posterior

urethra when this area begins to fill with urine

at the higher bladder pressures. Sensory signals

from the bladder stretch receptors are

conducted to the sacral segments of the cord

through the pelvic nerves and then reflexively

back again to the bladder through the

parasympathetic nerve fibers by way of these

same nerves. When the bladder is only partially


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filled, these micturition contractions usually

relax spontaneously after a fraction of a minute, the detrusor muscles stop

contracting,

and pressure falls back to the baseline. As the

bladder continues to fill, the micturition

reflexes become more frequent and cause

greater contractions of the detrusor muscle.

Once a micturition reflex begins, it is self-

regenerative That is, initial contraction of the

bladder activates the stretch receptors to cause

a greater increase in sensory impulses to the

bladder and posterior urethra, which causes a

further increase in reflex contraction of the

bladder; thus, the cycle is repeated again and

again until the bladder has reached a strong

degree of contraction. Then, after a few

seconds to more than a minute, the self-

regenerative reflex begins to fatigue and the

regenerative cycle of the micturition reflex

ceases, permitting the bladder to relax. Thus,


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the external sphincter, urination will occur. If

not, urination will not occur until the bladder

fills still further and the micturition reflex

becomes more powerful. Facilitation or

Inhibition of Micturition by the Brain .The

micturition reflex is a completely autonomic

spinal cord reflex, but it can be inhibited or

facilitated by centers in the brain. These

centers include

(1) Strong facilitative and inhibitory centers in

the brain stem, located mainly in the pons, and

(2) several centers located in the cerebral

cortex that are mainly inhibitory but can

become excitatory. The micturition reflex is the

basic cause of micturition, but the higher

centers normally exert final control of

micturition as follows:

1. The higher centers keep the micturition

reflex partially inhibited, except when


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micturition is desired.

2. The higher centers can prevent micturition,

even if the micturition reflex occurs, by

continual tonic contraction of the external

bladder sphincter until a convenient time

presents itself.

3. When it is time to urinate, the cortical

centers can facilitate the sacral micturition

centers to help initiate a micturition reflex and

at the same time inhibit the external urinary

sphincter so that urination can occur.

Voluntary urination is usually initiated in the

following way: First, a person voluntarily

contracts his or her abdominal muscles, which

increases the pressure

in the bladder and allows extra urine to enter

the bladder neck and posterior urethra under

pressure, thus stretching their walls. This

stimulates the stretch receptors, which excites


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the micturition reflex and simultaneously

inhibits the external urethral sphincter.

Ordinarily, all the urine will be emptied, with

rarely more than 5 to 10 milliliters left in the

bladder

(Reference Guyton and halls text book of

medical physiology vol.1 page no.309-310.)

Q: Define Filtration Coefficient and

Filtration. Give their normal value.

Enumerate factors which affect Glomerular

Filtration Rate?

Ans:Filtration co-efficient (Kf): It is measure of the product of

the hydraulic conductivity and surface area of the

glomerular capillaries.

Formula of filtration co-efficient:

Kf=GFR/Net filtration pressure

Filtration: Filtration is commonly the mechanical or

physical operation which is used for the separation of

solids from fluids (liquids or gases) by interposing a


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hyperosmolar. The Hormone ADH is responsible for the

UT3 opening and the reabsorption of water in from the

tubules in order to concentrate the urine so in conditions

when there is less availability of water ADH is secreted

which reabsorbs water and also makes kidney

interstitium more hyperosmolar for the purpose of

concentrating the urine.

(Reference Guyton and halls text book of medical

physiology vol.1 page no.350-351.)

Q: what are features of METABOLIC ACIDOSIS?

How is it compensated?

Answer: features of METABOLIC ACIDOSIS:

Metabolic acidosis can result from several general causes

(1) Failure of the kidneys to excrete metabolic acids normally

formed in the body,

(2) Formation of excess quantities of metabolic acids in the

body,

(3) Addition of metabolic acids to the body by ingestion or


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is absorbed from the gastrointestinal tract into the blood and

increases the bicarbonate portion of the bicarbonate buffer

system, thereby increasing pH toward normal. Sodium

bicarbonate can also be infused intravenously, but because of the

potentially dangerous physiologic effects of such treatment,

other substances are often used instead, such as sodium lactate

and sodium gluconate. The lactate and gluconate portions of the

molecules are metabolized in the body, leaving the sodium in

the extracellular fluid in the form of sodium bicarbonate and

thereby increasing the pH of the fluid toward normal.

Q: Define renal threshold. How is glucose

reabsorbed in the renal tubules? What is the

normal values of transport maximum for

glucose?

Answer: Renal Threshold:

The renal threshold is the concentration of a

substance dissolved in the blood above which

the kidneys begin to remove it into the urine.


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3. Amount excreted=0

4. % of filtered Load Reabsorbed=100

Q: Give a summary of functions of Kidneys?

Answer: Kidneys perform a number of functions as

follows:

1. Role in excretion: it excretes urea, creatinine,

metabolites, drugs, toxins

2. Regulations of Ions and Urea: kidneys absorbs as

well as excretes many ions like Na, K, Ca, and PO4 in

its tubules.

3. Acid base balance: kidney through phosphate

buffer helps the body to resist any change in the pH

of the body.

4. Synthetic functions: it produces 1, 25

dihydroxycholecalciferol (activated vitamin D).

5. Homeostasis of water:

Physio Uhs Solved Past Papers 2nd Year(2)

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