Anatomy and Physiology MCQs

The notch in the left lung that accommodates the heart

The respiratory membrane

The point where the primary bronchus and arteries and veins enter the lung

The membrane that surrounds each lung

The two-layered pleura surrounds the lung. The visceral pleura is attached to the lung while the parietal pleura is attached to the inside of the body wall. Choice C is the hilum, and choice A is the cardiac notch.

Author: rikazzz Comment

Cells and Tissues

The nucleic acid which carries the information for protein synthesis from the cell nucleus to the ribosomes is:

DNA

RNA

mRNA

tRNA

“Messenger” RNA carries the data (the message) from the chromosomes in the nucleus to the ribosomes in the cytoplasm.

Author: rikazzz Comment

Chemistry for Physiology

The element nitrogen exists as molecules, N₂. Which of the following representations of the bonding in a molecule of nitrogen is correct?

A N⁺ N−

B N–N

C N=N

N≡N

Nitrogen is placed in Period VA of the periodic table and so needs to share three electrons. That is, it needs to form three covalent bonds.

Author: rikazzz Comment

Renal System

Which one of the following correctly lists the organs of the renal system?

Two kidneys, two adrenals, one bladder, two urethras, one ureter

Two kidneys, one urethra, one bladder, two ureters

Two kidneys, one prostate, one bladder, two ureters, one urethra

Two kidneys, two urethras, one bladder, one ureter

There are two ureters (one from each kidney) and one urethra from the bladder to the outside. The prostate is not part of the renal system and is present in males only.

Author: rikazzz Comment

Respiratory System

Why is oxygen therapy – allowing a patient to breathe in an atmosphere in which the proportion of oxygen is greater than 20% – beneficial? Because the:

Partial pressure of CO₂ in the inhaled air is decreased making it easier to clear CO₂ from the lungs.

Partial pressure of oxygen in the lungs is increased allowing more oxygen to dissolve in the alveolar fluid.

Oxygen molecule is smaller than the nitrogen molecule so a greater number of moles of air can be drawn into the lungs with each breath.

Patient is required to inhale less frequently and this reduces the strain on the respiratory system.

Breathing an atmosphere where oxygen is at greater than 20% concentration (by volume) will mean more oxygen will cross the respiratory membrane to dissolve in plasma. In many cases this will be of benefit to the patient.

Author: rikazzz Comment

Chemistry for Physiology

A bag containing 1 L of prepared intravenous saline solution is printed with “isotonic approximate osmolality 300 mOsm”. What is meant by osmolality?

It is the number of osmoles dissolved in kilogram of water.

It is the number of osmoles dissolved per litre of saline solution.

Osmolality is an alternate spelling for osmolarity, the number of osmole per litre of solution.

Osmolality is used for covalent solutes, while osmolarity is used for ionic solutes.

As osmolality (osmol/kg) refers to the concentration within a mass (a kilogram) of solution it is unaffected by the temperature of the solution. Osmolarity (with an “r”) in osmol/L refers to the concentration within a volume of a litre of solution. For human physiological solutions which are relatively dilute, there is virtually no difference between the concentrations of solutions when expressed as osmolarity or osmolality.

Author: rikazzz Comment

Renal System

Four sections of the vasculature of the kidney tubule are listed below. Which one lists them in correct order of blood flow from left to right?

Efferent arteriole, glomerulus, afferent arteriole, peritubular capillaries

Afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries

Peritubular capillaries, afferent arteriole, glomerulus, efferent arteriole

Glomerulus, afferent arteriole, peritubular capillaries, efferent venule

The afferent arteriole carries blood into the glomerulus so must be first.

Author: rikazzz Comment

Cardiovascular System

If the radius of a blood vessel is halved, the blood flow through it drops to one sixteenth its previous value. This statement could be describing which of the following?

A decrease in pressure gradient