Anatomy and Physiology MCQs

Kupffer cell

Monocyte

Dendrocyte

Megakaryocyte

A megakaryocyte is the cell that produces the membrane-covered cell fragments known as platelets. It is not a macrophage. A dendrocyte is also known as a Langerhans cell or a granstein cell.

Author: rikazzz Comment

Respiratory System

Oxygen and carbon dioxide cross the respiratory membrane by the process of:

Countercurrent exchange

Diffusion

Active transport

Oxygen – carbon dioxide pump

The gases move by diffusion along their concentration gradients.

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Respiratory System

When performing cardiopulmonary resuscitation (“mouth to mouth”), what air enters the recipient from the resuscitator?

Stale air with some residual oxygen from the resuscitators lungs

Fresh air from the resuscitators lungs

Stale air from the lungs and fresh air from the anatomical dead space

Fresh air and stale air from the anatomical dead space

After an inhalation, the anatomical dead space (the ~150 ml air in the trachea and bronchi that has not reached the alveoli) contains air from the atmosphere, albeit now saturated with water vapour, that has not had its oxygen content depleted by gas exchange in the alveoli and hence is “fresh”. This air, plus some “stale” air from the alveoli, but with some residual oxygen, is exhaled into the recipient’s lungs.

Author: rikazzz Comment

Nervous System

Which of the following is true of unipolar neurons?

Horizontal and amacrine cells of the retina are unipolar neurons.

Most sensory neurons of the peripheral nervous system are unipolar.

All motor neurones that control skeletal muscles are unipolar.

Unipolar neurons are found in the retina of the eye.

These sensory neurons have their cell bodies in the dorsal root ganglion. Choice A would be true of anaxonic neurons. Choice C would be true of multipolar neurons. Choice D would be true of bipolar neurons.

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Chemistry for Physiology

In the context of fluid (water) balance, the body is said to have “two compartments”. What are they?

The vascular and the interstitial compartments

The intracellular and the interstitial compartments

The lymph and the vascular compartments

The extracellular and the intracellular compartments

Outside the cells and inside the cells include everything.

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Cardiovascular System

According to Poiseuille’s law of fluid flow, the volume flow rate, V, is proportional to radius to the fourth power. What would happen to the volume flow rate of blood if the diameter of an artery decreased to 20% (1/5) of its original diameter? V would:

Be one fifth (0.2) of its original value.

Be one twenty-fifth (0.04) its original value.

Be 1/625 (0.0016) of its original value.

Be five times its original value.

(1/5)⁴ = (0.2)⁴ = 0.0016. Narrowing of arteries has dire consequences for blood flow.

Author: rikazzz Comment

Cardiovascular System

What are the blood vessels called that allow exchange of materials though their walls to occur?

Capillaries

Sinusoids

Arterioles

Anastomoses

Sinusoids are one type of capillary. Anastomoses are a network of capillaries.

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Biomechanics

In straight leg traction (Buck’s extension), the force of counter-traction is supplied by friction (between the patient and the bed) and also by:

The component of the patient’s weight that is perpendicular to the bed

The component of the patient’s weight that is parallel to the bed

Gravity acting on the hanging mass

Using cords to attach the patient to the head of the bed

The bed is tilted head down so that patient is tending to side away from the traction mass.

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Chemistry for Physiology

Amino acids are the building blocks of all proteins. As more amino acids are added, the protein chain tends to fold upon itself in a characteristic way. This characteristic of a protein is called the:

Primary structure

Secondary structure

Tertiary structure

Quaternary structure

The shape produced by folding is the tertiary structure. Primary structure is the sequence in which the amino acids are joined. Secondary structure is any repetition of the primary structure. Quaternary structure does not exist.

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Cardiovascular System

Given that we have the following blood pressures at the arterial end of a capillary (blood pressure, 28 mmHg, and osmotic pressure, 20 mmHg), what is the net filtration pressure at this end?

0.71 mmHg

1.4 mmHg

8 mmHg

48 mmHg

BP promotes the outflow of liquid and solutes from the arterial end, while the blood’s osmotic pressure promotes the inflow of water. That is, these two influences are opposing. Hence 28–20 = 8 mmHg.

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