Question

1. Hypotension will lower the plasma osmolarity, blood pressure, and blood volume. This will activate the renin-angiotensin-aldosterone system. Overhydration will increase the blood volume. This will trigger the cardiac atrial cells to secrete atrial natriuretic peptide (ANP). Fasting will increase the plasma osmolarity, decrease blood pressure and blood volume. This will trigger the secretion of anti-diuretic hormone (ADH).

a. True

b. False

2. What is TRUE about acetylcholine? There may be more than one answer.

a. Acetylcholine is a neurotransmitter that binds to the nicotinic receptor at the motor-end-plate of a muscle fiber and it is a neuromodulator when it binds to the nicotinic receptor at the dendrites of a post-ganglionic neuron.

b. It takes two acetylcholine to open the gate of a nicotinic receptor, which will cause a greater influx of Na⁺ compared to the amount of efflux of K⁺.

c. Acetylcholine binds at the muscarinic receptors at the atria only of the heart to decrease the heart rate.

d. Acetylcholine is a neurocrine but it is never found in the blood because it is not a neurohormone.

e. Acetylcholine causes an excitatory response on the muscle fiber when it binds to the acetylcholine esterase.

3.

What force favors the glomerular filtration process?

a. Hydrostatic pressure in the glomerular capillary

b. Osmotic pressure in the glomerular capillary

c. Hydrostatic pressure in the Bowman's capsule

d. Osmotic pressure in the Bowman's capsule

e. Hydrostatic pressure and osmotic pressure in the glomerular capillary

Answer 1

Answer 1: TRUE

Explanation: Decrease in blood volume causes decrease in blood pressure. Whenever blood volume decreases Anti diuretic hormone (ADH) is released from posterior pituitary which increases the reabsorption of water from renal tubules which leads to increase in blood volume because of which blood pressure increases. Whe blood volume increases then blood pressure increases. Increase in blood volume triggers release of Atrial Natriuretic Peptide (ANP) which increases GFR and diuresis from kidney due to which urine volume increases and more water is lost in urine this decreases the blood volume.

Answer 2:

The right choice is: (a) and (c)

Explanation: Acetylcholine acts on nicotinic receptors on neuromuscular junction and causes sodium to enter inside the cell and leads to depolarization. Acetylcholine acts on muscuranic receptors of heart and decreases heart rate.

Answer 3:

The right choice is: (e)

Explanation: GFR is affected by both hydrostatic pressure and colloid osmotic pressure on either side of capillary of glomerulus, generally hydrostatic pressure is greater. Vasodilation of afferent arteriole causes decrease in resistance to the flow of blood which causes increase in the glomerular capillary hydrostatic pressure which increases GFR.