B 3.2 Transport LO 1-6

Which adaptation of capillaries allows for efficient exchange of substances between the blood and surrounding tissues?

• Thick, multilayered walls

• Large lumen diameter

• Thin walls and a large surface area due to branching

• High pressure flow

Fenestrated capillaries are specifically adapted to:

• Provide a large surface area for exchange

• Facilitate rapid exchange of fluids and solutes

• Withstand high blood pressure

• Prevent the backflow of blood

What is the primary role of capillaries in the circulatory system?

• To transport blood away from the heart

• To exchange substances between blood and tissues

• To return blood to the heart

• To increase blood pressure

In micrographs, which characteristic helps distinguish an artery from a vein?

• The thickness of the vessel wall relative to the lumen diameter

• The presence of one-way valves

• The size of the lumen

• The type of blood flow (arterial or venous)

Which of the following statements is true about veins compared to arteries?

• Veins have thicker walls relative to their lumen diameter.

• Veins have a smaller lumen and more smooth muscle.

• Veins have a larger lumen and thinner walls.

• Veins are primarily involved in high-pressure blood transport.

In comparing micrographs of arteries and veins, which feature is indicative of an artery?

• A large, wide lumen

• A thin wall with little muscle tissue

• A thick wall with a small lumen

• The presence of valves

How do the elastic tissues in arteries help them function effectively?

• • By allowing arteries to constrict and dilate

• • By providing a smooth inner lining to reduce friction

• • By stretching to accommodate blood volume and recoiling to maintain blood pressure

• • By preventing the backflow of blood

Which layer of an artery wall is primarily responsible for regulating blood flow by altering the vessel diameter?

• Tunica intima

• • Tunica media

• • Tunica adventitia

• • Endothelium

The high-pressure flow in arteries is accommodated by:

• • A thick layer of smooth muscle

• • A large lumen diameter

• Valves that prevent backflow

• • Elastic fibres in the arterial walls

What is the correct method to manually measure pulse rate using the radial artery?

• • Place fingers on the wrist, count beats in 15 seconds, and multiply by 4

• • Place a stethoscope on the chest and count beats

• • Use a smartphone app to detect blood flow changes

• • Measure the electrical signals with a heart rate monitor