Anatomy and Physiology MCQs

Which of the following body parts is the least sensitive to radiation?

Lens of the eye

Red bone marrow

Gonads

Hands

The other three body parts are all named by the ICRP and have been assigned a “radiation weighting factor” determined by their known sensitivity to radiation.

Author: rikazzz Comment

Renal System

What part of the renal tubule is NOT able to reabsorb water?

The descending limb of the loop of Henle

The proximal convoluted tubule

The ascending limb of the loop of Henle

The distal convoluted tubule

The ascending limb is impermeable to water.

Author: rikazzz Comment

Skeleton and Joints

The axial skeleton groups together which sets of bones?

The arms and hands, the legs and feet, shoulder girdle and pelvic girdle

The head, shoulder girdle, arms and hands

The thoracic cage, vertebral column, shoulder girdle, the pelvic girdle, the skull and facial bones

Bones of the skull and face, thoracic cage and vertebral column

Choice A describes the appendicular skeleton. Choices A and D are complementary.

Author: rikazzz Comment

Nervous System

Depolarisation of the cell membrane involves:

Sodium channels opening to allow Na⁺ to flow in

Potassium channels opening to allow K⁺ to flow in

Chloride pumps quickly pumping large amounts of Cl− outside

Electrical attraction between K⁺ inside and Cl− outside

The influx of positive Na ions changes the polarisation of the cell from negative inside to positive inside at that location on the membrane. This reversal is called depolarisation.

Author: rikazzz Comment

Cardiovascular System

What effect will increasing the concentration of red cells in blood have? It will:

Decrease blood viscosity and increase aortic pressure

Increase blood viscosity and decrease aortic pressure

Increase blood viscosity and increase aortic pressure

Decrease blood viscosity and decrease aortic pressure

Viscosity will increase as the number of RBC increases. This will also increase the resistance to flow so BP in the aorta will increase a bit.

Author: rikazzz Comment

Renal System

The nephron of the kidney consists of which of the following structures?

Glomerulus, renal tubule and collecting duct

Bowman’s capsule, proximal convoluted tubule, loop of Henle and distal convoluted tubule.

Glomerulus and renal tubule

Renal tubule and collecting duct

The glomerulus and renal tubule together constitute the nephron.

Author: rikazzz Comment

Ionising Radiation

Why is radiotherapy using high-energy x-rays an effective way of treating some cancer? Because:

If enough energy is deposited in tumour cells, they can be killed.

Most of the x-rays pass through the body without harming healthy tissue.

The dose to the skin surface is lower than with low-energy x-rays.

High-energy x-rays do not kill healthy cells.

The ability of x-rays to be switched off and on and to deposit enough energy within a cell to kill it makes it suitable for treatment of cancer tumours.

Author: rikazzz Comment

Body Temperature, Energy and Heat Loss

A person lightly dressed in shorts, shoes and a shirt is sitting on a cushioned chair in their shady backyard where the air temperature is 12 °C. There is no wind, yet they feel uncomfortably cool. What is their major avenue of heat loss?

Conduction

Evaporation of sweat

Radiation

Convection

The lack of wind minimises convective loss, while the light clothing prevents conductive loss to the chair and ground. The low temperature means that sweating is not occurring. Radiative loss will occur as the body temperature is greater than that of the surroundings.

Author: rikazzz Comment

The Physics of Waves: Light Waves, Sound Waves and Ultrasound

What is the measure known as “sound level”?

A subjective measure of the perceived loudness of a sound (in dB)

A graph of the levels of sound of different frequencies that we perceive as equal in loudness (in phone)

The frequency of the sound that produces the loudest response in a healthy hearing mechanism (in Hz)

The objectively measured amount of sound energy carried by a sound wave (in W/m²)

Sound level is subjective, in that it is perceived by the hearer and depends on the frequency/ies of the sound. The unit is the decibel.

Author: rikazzz Comment

Measurement, Errors, Data and Unit Conversion

What information does the “standard deviation” of a mean value tell us?

It gives us the healthy range of values for the measured physiological quantity.

It is the range within which 68% of measured values are found.

It tells us that the measured values are normally distributed.

It tells us the number of values that were used to calculate the mean.

C is also correct but choice B is the better answer.

Author: rikazzz Comment