Correct Answer - C
Ans. is 'c' i.e., Cerebellum

Cerebellum, through its connection with the red nucleus influences
the activity of brainstem reticular formation and thereby gamma
motor neuron activity.

Through its connections with the vestibular nucleus and
vestibulospinal tract, cerebellum influnences the activity of alpha
motor neurons.

Thus, normal cerebellar function is essential for the maintenance of
normal muscle tone and posture.

The cerebellum seems to play crucial roles in walking as well as
maintaing a standing posture.

Cerebellar vermis plays an important role in maintenance of
standing postuk.

Basal ganglia is also involved in maintaining posture by acting as
relay center for extrapyramidal pathways. But its role is not as
important.


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Correct Answer - A
Ans. is 'a' i.e., Generation of HCO-3 in RBCs

Carbon dioxide is transported in blood as plasma bicarbonate.

Red blood cells (RBCs) play a major role in the mechanism because
RBCs contain the enzyme carbonic anhydrase that catalyzes the
reaction CO2 + H2O = HCO3 +
Hence when CO2 diffuses into the RBC, it reacts chemically with
water to generate HCO3-.
The ft ions are mopped up by hemoglobin, which is an excellent
buffer.
.
This enables the reaction to proceed in the forward direction.
The HCO3- ions generated diffuse out into the plasma in exchange
for Cl- ions that diffuse into RBCs simultaneously.

The movement of chloride ions into RBC is called Chloride shift.
The above events results in an increase in total number ions inside the RBC, which increases its osmolarity.

As a result, water enters the RBC through osmosis.

The RBCs carrying CO2 in bicarbonate form will therefore be
somewhat larger than normal.

Hence the hematocrit of venous blood is normally 3% greater than
that of arterial blood.

o In the lungs, Cl- moves out of the RBCs and they shrink.

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Correct Answer - B
Ans: B. Obstructive lung disease

Measurement of the bronchodilator response of forced expiratory
volume in 1 second (FEV1) is an important method in clinical
respiratory medicine.

This measurement is used to predict the response to bronchodilator treatment and is part of the diagnosis of COPD and asthma.

The bronchodilator response of forced vital capacity (FVC) has less
clinical use than the bronchodilator response of FEV1 but may add
important clinical physiological information

Airway obstruction was defined as FEV1/FVC ratio below lower limit
of normal (LLN) before bronchodilation, and COPD was defined as an FEV1/FVC ratio below LLN after bronchodilation.

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Correct Answer - D
Ans. D. Cholinergic

An exercise is a form of stress, and like most stresses, is accompanied by sympathetic overactivity.

Skeletal muscles have both sympathetic noradrenergic
vasoconstrictor fibers and sympathetic cholinergic vasodilator fibers.

Vasoconstrictor nerve fibers act mainly on veins.
Venoconstriction improves venous return and helps in improving
cardiac output.
On the other hand, sympathetic cholinergic fibers, which are unique
to skeletal muscles, bring about arteriolar dilatation and thereby
increase muscle blood flow.

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Correct Answer - B
Ans: B. Hyperparathyroidism

The serum calcitonin level is strongly increased in this type of
cancer.

After successful total thyroidectomy, calcitonin is no
longer detectable.

Increasing concentrations of calcitonin after therapy indicate relapse or metastasis.

Hyperparathyroidism is
present in 20-30% of patients with medullar thyroid carcinoma.

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Correct Answer - c
Ans. C. Obstructive sleep apnea [OSAI [Ref Harvard ed] Apnea Hypopnea Index (AHI)

The AHI is the number of apneas or hypopneas recorded during the
study per hour of sleep.

It is generally expressed as the number of events per hour.

Based on the AHI, the severity of OSA is classified as follows:
None/Minimal: AHI < 5 per hour
Mild : AHI 5, but < 15 per hour
Moderate : AHI 15, but < 30 per hour
Severe : AHI 30 per hour.

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Correct Answer - D
Ans. D. Ca+2
[Ref Principles of medical physiology p.801]

Effects of ion concentration change on membrane potential:

* Hypercalcemia
- An increase in extracellular Ca2+ concentration can stabilize the
membrane by decreasing excitability.

* Hypocalcemia
- Calcium ion is membrane stabilizers.
- A decrease in extracellular Ca2+ concentration increases the
excitability of nerve by decreasing the amount of depolarization
necessary to produce the action potential.
- Hyperexcitability is seen.

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Correct Answer - D
Ans. D. Cholinergic

An exercise is a form of stress, and like most stresses, is accompanied by sympathetic overactivity.

Skeletal muscles have both sympathetic noradrenergic
vasoconstrictor fibers and sympathetic cholinergic vasodilator fibers.

Vasoconstrictor nerve fibers act mainly on veins.
Venoconstriction improves venous return and helps in improving
cardiac output.


On the other hand, sympathetic cholinergic fibers, which are unique
to skeletal muscles, bring about arteriolar dilatation and thereby
increase muscle blood flow.

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Correct Answer - B
Ans. B. Binding capacity to albumin

Plasma protein binding of a substance decreases is glomerular
filtration.

Only unbound substances are filtered.

Glomerular filtration does not depend on lipid solubility as filtration occurs through the pores in glomerular membrane
(Lipid solubility affects the transport of substance across cellular membrane)

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Correct Answer - C
Ans. C. Free nerve endings
Pain receptors are free nerve endings, i.e. they are not enclosed in a capsule.

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