Anatomy and Physiology MCQs

“X” is still technetium as the atomic number (43) has not changed. Consequently, the chemical behaviour of the two nuclides is the same. A daughter nucleus may or may not be radioactive (in this case it is).

Author: rikazzz Comment

Chemistry for Physiology

Given the concentration of Na+ inside the cell, it is about 10 mmol/L, while it is 140 mmol/L in the extracellular fluid. The values for K+ are 140 mmol/L inside the cell and 4 mmol/L extracellularly. In what directions would these ions diffuse?

Na+ would diffuse into the cell while K+ would diffuse out.

K+ would diffuse into the cell while Na+ would diffuse out.

Both Na+ and K+ would diffuse out of the cell.

Both Na+ and K+ would diffuse into of the cell.

Na would diffuse form 140 mmol/L to 10 – the direction of its concentration gradient which is from outside to inside. K would diffuse from 140 mmol/L to 4, that is, from inside to outside.

Author: rikazzz Comment

Renal System

Caffeine is a diuretic. What is its mode of action?

It inhibits Na+ reabsorption from the filtrate hence the water reabsorption that follows.

It promotes the secretion of antidiuretic hormone (ADH), hence the insertion of aquaporins in the tubule cell membrane.

It promotes the secretion of aldosterone, hence the absorption of Na+.

It inhibits the secretion of atrial natriuretic peptide (ANP), hence the absorption of Na+.

A diuretic causes a greater volume of urine to be produced. This will happen if water is NOT reabsorbed from the filtrate. The other three choices will result in a decrease in the volume of urine produced.

Author: rikazzz Comment

Nervous System

What is the “limbic system” of the brain?

It keeps the cortex alert and aroused.

It is the emotional or affective part of the brain.

It filters out repetitive, familiar or weak sensory signals.

It receives sensory information before passing it the cerebral cortex.

The limbic system is also involved in memory and learning. Choices A and C refer to the reticular formation of the brain. Choice D is performed by the thalamus.

Author: rikazzz Comment

Cardiovascular System

Consider that at a point in time, an arterial blood pressure – stated in mmHg – is measured to be 115. Given that the atmospheric or air pressure was 760 mmHg at the time of blood pressure measurement, what is the actual blood pressure?

760–115 = 645 mmHg.

The blood pressure is actually 115 mmHg.

115/760.

115 + 760 = 875 mmHg.

Atmospheric pressure is a “relative” zero, with values above atmospheric being termed “positive”, while values below are termed “negative”. A blood pressure of 115 mmHg means 115 above atmospheric pressure, so the actual pressure is 115 + 760 = 875 mmHg.

Author: rikazzz Comment

Nervous System

What is the role of the hypothalamus?

It receives sensory input and relays it to the cerebral cortex.

It is the autonomic control centre which directs the function of the lower CNS.

It uses past experience to analyse and act on sensory input.

It integrates sensory information from association areas and performs abstract intellectual functions.

Hypothalamus is the main visceral control centre of body homeostasis. It is the autonomic control centre from which orders flow to lower CNS centres for execution.

Author: rikazzz Comment