Anatomy and Physiology MCQs

Cardiovascular System

Which of the following statements about platelets is INCORRECT? They:

Adhere to collagen fibres of damaged tissue

Release phospholipids which combine with “clotting factors” to produce prothrombin activator

Are cell fragments derived from megakaryoblasts

Are part of the “extrinsic pathway” for the formation of prothrombin activator

Platelets do not release phospholipids.

Author: rikazzz Comment

Integument

One of the following cell types is a macrophage. Which one?

Keratinocytes

Melanocytes

Dendrocytes

Merkel cells

Dendrocytes are able to engulf bacteria and debris. The melanocytes and keratinocytes of the skin produce melanin and keratin, respectively, while Merkel cells are a sensory structure.

Author: rikazzz Comment

Endocrine System

Which structure is composed of glandular epithelial tissue?

The thalamus

The anterior pituitary

The posterior pituitary

The hypothalamus

The anterior pituitary produces and releases six hormones.

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Cardiovascular System

Consider a capillary where the blood hydrostatic pressure is 3300 Pa at the arterial end and 2000 Pa at the venous end. If the difference between the osmotic pressures inside and outside the capillary is 2900 Pa, what would be the net pressure difference between the surrounding tissue and blood in the venous end of the capillary?

400 Pa

900 Pa

1300 Pa

4900 Pa

Blood hydrostatic pressure tends to move water and solutes out of the capillary, while osmotic pressure tends to move water into the capillary. Taking the outward direction as positive: net pressure at the venous end is = 2000–2900 = −900 Pa and so is directed into the capillary.

Author: rikazzz Comment

Ionising Radiation

When compared to visible light, which is not very penetrating, why can radiation such as x-rays and gamma rays pass right through the human body? Because:

The density of the human body is relatively low.

They have no mass and no charge.

Atoms in the body are mostly empty space.

They have very high energy.

X and gamma rays are high-energy radiation, which means high frequency, which means short wavelength and which means that many of the photons will pass through the body without interacting with any atoms. The other three choices do not distinguish between different types of radiation.

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Skeleton and Joints

The appendicular 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

The appendages (arms and legs) and the girdles form the appendicular skeleton.

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Cardiovascular System

Why do arteries have more elastic and muscular tissue than veins?

Arteries need to expand and contract as blood flows through them.

Arteries need carry a greater volume of blood than do veins.

To ensure that blood flows only in the direction away from the heart.

In order to support the larger diameter of arteries compared to veins.

Arteries distend to accept the volume of blood pumped into them and then elastically recoil to assist blood flow during diastole. The ability to contract enables arteries to direct blood away from tissues that require less blood. Arteries contain less volume than veins; the heart ensures forward flow; veins have a larger diameter than arteries.

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Cells and Tissues

What is the term used to describe the bulk movement of a large number of molecules out of a cell?

Lymphocytosis

Exocytosis

Thrombocytosis

Endocytosis

“Exo-” refers to movement from inside to the outside (-cytosis is a suffix that means in reference to cells).

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Respiratory System

When the diaphragm contracts, which of the following will happen in the lungs?

Air pressure will increase, volume will decrease and exhalation will occur.

Air pressure will decrease, volume will increase and exhalation will occur.

Air pressure will decrease, volume will increase and inhalation will occur.

Air pressure will increase, volume will increase and inhalation will occur.

Contracting the diaphragm will increase the volume of the lungs, which will decrease the pressure of the contained air. Consequently, air from the room will be pushed into the lungs (inhalation occurs).

Author: rikazzz Comment

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

The wave equation may be written in symbols as v = fλ where f stands for frequency, v stands for velocity and λ stands for wavelength. If a wave has a speed of 3 × 10⁸ m/s, what is its frequency and wavelength?

f = 10,000 Hz and λ = 0.0003 m

f = 5 × 10¹⁴ Hz and λ = 6 × 10−⁷ m

f = 6 × 10⁴ Hz and λ = 0.5 × 10−⁴ m

f = 2 MHz and λ = 3 × 10⁵ m

Which combination of frequency and wavelength will give the speed 3 × 10⁸ m/s? v = fλ = 5 × 10¹⁴ Hz × 6 × 10−⁷ m = 30 × 10^14–7 = 30 × 10⁷ = 3 × 10⁸

Author: rikazzz Comment