6.2

Question 1

components of blood

Answer 1

1. Plasma (dissolves or carries all other components of blood, nutrients, wastes)
2. Red blood cells (transport oxygen in hemoglobin molecules)
3. Leukocytes (phagocytes and lymphocytes)
4. Platelets (blood clotting)

Question 2

describe the artery (red)

Answer 2

1. 3 layers (tunica externa, media, interna)
2. Able to stretch
3. thick, muscular
4. carries blood away from the heart
5. larger than 10mm
6. Abundant muscle and elastic fibers in wall
7. Dont need valves since pressure of blood from heart is large enough to make flow unidirectional

Question 3

Describe Capillary

Answer 3

1. 1 layer (tunica intima)
2. very thin wall (one cell thick)
3. Around 10mm
4. No muscle and elastic fibres in wall
5. site of gas exchange with tissue cells

Question 4

Vein (Blue)

Answer 4

1. Carries blood towards the heart
2. much larger than 10mm
3. Thin wall, wide lumen
4. 3 layers (tunica externa, media, intima)
5. Small amounts of muscle and elastic fibres in wall
6. Valves in veins

Question 5

Does each ventricle in the heart have valves

Answer 5

yes

Question 6

what is coronary heart disease

Answer 6

coronary arteries are blocked with fat. Can treat by inserting a stent to expand artery

Question 7

Describe the movement of blood in the heart

Answer 7

blood returning from body (not lungs) enters into right atrium via superior vena cava (deoxy). Blood goes from R.A then R.V then leaves pulmonary artery to lungs (where it is oxy). Blood returns to pulmonary vein, goes to L.A, then L.V, then aorta, where it is pumped around the body

body to lungs (deoxy to oxy)
lungs to body (oxy to deoxy)

Question 8

Name the 4 valves of the heart

Answer 8

Tricuspid valve (valve connecting R.A and R.V)
Bicuspid Valve (valve connecting L.A and L.V)
Pulmonary valve (valve at bottom of pulmonary artery)
Aortic Valve (valve at bottom of Aorta)

Question 9

Describe the Sinoatrial Node

Answer 9

The Sinoatrial node is the pacemaker and it sends out an electrical impulse causing atria to contract.

Question 10

Describe the Atrioventricular Node

Answer 10

The AV sends out an electrical impulse causing the ventricles to contract. AV sends a signal via the bundle of His to Purkinje Fibres

Question 11

Where is the electrical impulse of SA and AV sent from

Answer 11

The medulla oblongotta

Question 12

what is noradrenaline

Answer 12

the neurotransmitter that speeds up the myocardial contraction

Question 13

what is acetylcholin

Answer 13

a neurotransmitter that decreases the rate of myocardial contraction

Question 14

what happens during systole

Answer 14

contraction of ventricles, blood pushed out heart, blood pressure increased, bicuspid and tricuspid valves shut creating “dum”

Question 15

what happens during diastole

Answer 15

heart is relaxed, blood in all 4 chambers, bicuspid and tricuspid valves open, pressure decrease, semilunar valves closed creating second “dum”

Question 16

difference between semilunar valves and atrioventricular valves

Answer 16

Semilunar valves: pulmonary valve and aortic valve

Atrioventricular valve: bicuspid and tricuspid valve

Question 17

what is blood pressure

Answer 17

The measure of systolic and diastolic pressure of blood in the wall of arteries

Question 18

Achievements of William Harvey

Answer 18

Blood flow is unidirectional. Suggested blood returns back to the heart through veins instead of being consumed by the body. Predicted presence of capillaries. overturned theory developed by Galen

Question 19

what is arteriosclerosis, what are its causes, and consequences

Answer 19

developement of fatty tissue (atheroma) in arteries. Caused by high concen. LDL cholesterol, high blood-glucose levels (obesity, over-eating), high b.p., onsumption of trans-fat. Consequences: angina, heart attack (coronary arteries), stroke (brain arteries), kidney disease (renal arteries), aortic aneurysm (aorta)