Topic 1- Lifestyle, Health, And Risk

Question 1

Describe the function of arteries, veins, and capillaries

Answer 1

Arteries- transport blood away from the heart at high pressures

Veins- transport blood to the heart, usually at low pressures

Capillaries- join arterials and venules

Question 2

What’s an endothelium?

Answer 2

It lines the lumen of blood vessels. It’s very smooth and reduces friction for free blood flow.

Question 3

Compare the structure of a vein vs an artery

Answer 3

Artery:
Narrow lumen, thicker walls, more collagen, elastic fibers, no valves

Veins:
Wide lumen, thinner walls, less collagen, elastic fibers, valves

Question 4

What is the function of collagen?

Answer 4

Protects the vessel from overstretching and keeps it strong

Question 5

Function of muscle?

Answer 5

Withstand high pressurw

Question 6

Function of elastic tissue?

Answer 6

Contact and relax, and maintains blood pressure

Question 7

Why is the endothelium highly folded in arteries?

Answer 7

It enables it to expand under high pressure

Question 8

Describe an arteriole

Answer 8

Smaller, thinner muscle, elastic layers - because blood pressure is decreasing.

Question 9

Describe the safety mechanism that capillaries have

Answer 9

The blood pressure at this point have high resistance bc more contact with the wall

This slows down flow

Reduces pressure

Saves damage

Question 10

Why are veins surrounded by skeletal muscle?

Answer 10

It compresses the veins and pushes the blood along

Question 11

What happens when contraction occurs in terms of volume and pressure?

Answer 11

Volume decreases pressure increases

Question 12

Describe arterial systole

Answer 12

Pressure increases, causes AV valves to open

Blood forced into ventricle

Question 13

Describe ventricular systole

Answer 13

Pressure increases

Pressure in ventricles rise above that in atria, causing AV valves to close, preventing back flow

Pressure in ventricles rises above that in aorta and pulmonary artery, causing SL valves to open

Blood is now forced into arteries and out of the heart

Question 14

Describe the 4 stages of atherosclerosis

Answer 14

1. Damage- endothelium damaged
2. Inflammatory response- WBC move into artery wall. Cholesterol accumulates -> atheroma
3. Plaque- calcium builds up-> plaque -> less elasticity -> called atherosclerosis
4. More damage- plaque causes artery to become narrower -> hard to pump blood -> high blood pressure

Question 15

Stages of blood clotting?

Answer 15

Blood + exposed collagen -> prothrombin converted to thrombin
Thrombin (enzyme) catalyses fibrinigin -> fibrin
Fribrin strands form a tangled mesh that traps blood cells to make a clot

Question 16

How does angina occur?

Answer 16

Narrow coronary arteries-> limits amount of o2 reaching heart muscle -> chest pain (angina)

Question 17

How does heart attack occur?

Answer 17

Fatty plaque in coronary artery ruptures -> cholesterol is released -> rapid clot formation -> blood supply to heart can be blocked -> heart muscle permanently damaged -> heart attack

Question 18

What’s systole?

Answer 18

Contraction

Question 19

What’s diastole?

Answer 19

Relaxation