Unit 2- Blood Vessels

Question 1

What is heart rate?

Answer 1

The number of beats In one minute.

Question 2

What is stroke volume?

Answer 2

The volume of blood pumped out by each ventricle during contraction.

Question 3

What is cardiac output?

Answer 3

The volume of blood pumped through each ventricle per minute. CO = HR x SV.

Question 4

How does blood circulate?

Answer 4

From Artery ,capillary, to vein. Blood pressure decrease as blood moves away from the heart.

Question 5

What are the layers of arteries and veins?

Answer 5

Connective tissue, Muscle tissue, Endothelium, Lumen. —>

Question 6

Describe the role of arteries.

Answer 6

Connective tissue containing elastic fibres and a middle layer containing smooth muscle with more elastic fibres. The elastic walls stretch and recoil to accommodate the surge of blood after contractions. To control blood flow the smooth muscle undergoes vasoconstriction or vasodilation.

Question 7

What is vasoconstriction?

Answer 7

The smooth muscle surrounding artery contract narrowing central channel.

Question 8

What is vasodilation?

Answer 8

The smooth muscle surrounding the arteries relax widening the central channel (lumen).

Question 9

Describe pressure filtration.

Answer 9

1. Pressure filtration causes plasma to pass through capillary walls into the tissue fluid surrounding the cells.
2. Tissue fluid does not contain protein because it is too big to be passed through the capillary walls.
3. Tissue fluid supplies cells with glucose and oxygen. Carbon dioxide and other metabolic waste diffuse out cells into tissue fluid to be excreted.
4. Lymphatic vessels absorb excess tissue fluid and return it as lymph to the circulatory system.