Topic 13

Question 1

Which type of blood vessels take blood away from the heart?

Answer 1

arteries

Question 2

Which type of blood vessels take blood to the heart?

Answer 2

veins

Question 3

What the order of blood vessels the blood circulates through from the heart?

Answer 3

arteries, capillaries and veins

Question 4

What is the structure of an artery?

Answer 4

• outer layer of connective tissue containing elastic fibres
• a middle layer containing smooth muscle with more elastic fibres.
• a narrow lumen.

Question 5

What is the purpose of the elastic walls of an artery?

Answer 5

the elastic walls of arteries stretch and recoil to accommodatethe surge of blood after each contraction of
the heart.

Question 6

What is the purpose of the smooth muscle of an artery?

Answer 6

The smooth muscle can contractor relax causing vasoconstriction or vasodilation to control blood flow.

Question 7

What is the function of the capillaries?

Answer 7

Capillaries allow exchange of substance with tissues.

Question 8

What is the structure of a vein?

Answer 8

Veins have an outer layer of connective

tissue containing elastic fibres but a much thinner muscular wall than arteries and a wide lumen.

Question 9

What are the function of valves?

Answer 9

present in veins to prevent the back flow of blood between successive contractions of the heart.

Question 10

What is pressure filtration and how is tissue fluid made?

Answer 10

Blood arriving at the arteriole side of a capillary bed is at a higher pressure than blood in the capillaries. As blood is forced into these narrow vessels, it undergoes a form of pressure filtration and much of the plasma is squeezed out through the thin walls (tissue fluid)

Question 11

What does tissue fluid supply the cells with?

Answer 11

Tissue fluid supplies cells with glucose, oxygen and other substances.

Question 12

Where does the tissue fluid go?

Answer 12

Much of the tissue fluid returns to the blood. Lymphatic vessels absorb excess tissue fluid and return the
lymph fluid to the circulatory system, Carbon dioxide and other metabolic wastes diffuse out of the cells and into the tissue fluid to be excreted.

Question 13

What is lymph?

Answer 13

once the tissue fluid is in a lymphatic vessel.

Question 14

Although blood plasma and tissue fluid are very similar, what is the exception?

Answer 14

exception of plasma proteins (unable to pass through capillary walls)