L79- Physiology: Blood vessels+CV

Question 1

What is the cardiovascular system made up of?

Answer 1

heart and blood vessels

Question 2

how many valves are there in the heart ?

Answer 2

4

Question 3

what are the 4 valves in the heart called?

Answer 3

• Bicuspid (mitral)
• Tricuspid
• pulmonary valve
• aortic valve

Question 4

why do the papillary muscles contract with the ventricles?

Answer 4

to prevent back-flow

Question 5

How is blood pumped around the body?

Answer 5

using blood pressure

Question 6

what side of the heart is oxygenated?

Answer 6

left side

Question 7

where does the blood from the right side of the heart pump to?

Answer 7

goes to the lungs

Question 8

what are the different 3 layers in the heart wall?

Answer 8

• endothelium and endocardium
• myocardium (heart muscle)
• epicardium (outer layer)

Question 9

what happens to the sarcomere when the muscle contracts?

Answer 9

gets shorter

Question 10

actin the thin or thick filament?

Answer 10

thin

Question 11

what are intercalated discs?

Answer 11

cardiac muscle fibres branch and are interconnected by intercalated discs, which contain 2 types of membrane junctions

Question 12

what are some properties of heart muscles?

Answer 12

• striated
• branched
• joined by intercalated discs

Question 13

what are desmosomes?

Answer 13

a type of membrane junction food in intercalated discs they are mechanically important. Join 2 cells together

Question 14

what are gap junctions?

Answer 14

a type of membrane junction food in intercalated discs they are electrically important, In the transmission of an action potential

Question 15

what is a pericardial sac and whats its role?

Answer 15

• double walled sac
• tough covering= anchors the heart
• pericardial fluid

Question 16

what is happening during diastole?

Answer 16

the ventricles are filling up with blood the AV valves are open and closed open to fill ventricles, but

Question 17

what is happening during systole?

Answer 17

when the ventricles are contracting

Question 18

how many cusps do the semi lunar valves have?

Answer 18

3

Question 19

what is cardiac output?

Answer 19

Heart Rate x Stroke Volume

Question 20

what is the average HR?

Answer 20

70BPM

Question 21

How does the SA node help the heart contract?

Answer 21

SA node reaches threshold resulting in action potential which spreads through heart and induces heart to contract or have ‘heartbeat’ – occurs about 70 times in a min

Question 22

what affects stroke volume?

Answer 22

changes in venous return (Intrinsic control)
changes in sympathetic stimulation (Extrinsic control)
changes in afterload (disease)

Question 23

what is after load?

Answer 23

the pressure the heart must work against to eject blood during systole

Question 24

what is End Diastolic Volume (EDV)?

Answer 24

Volume in the heart at the end of diastole

filled

Question 25

what affects sympathetic stimulation?

Answer 25

```  increase contractility (b-adrenoceptors) = STRENGTH  Greater Ca2+  Greater cross-bridge cycling  independent of EDV  More complete ejection ```

Question 26

theres two circuits in the heart for blood flow, which side is involved in the systematic and pulmonary?

Answer 26

right- pulmonary | left- systematic

Question 27

arteries carry blood where? veins carry blood where?

Answer 27

away from heart- arteries | to heart- veins

Question 28

what are the 3 layers or tunics of the artery and veins?

Answer 28

 Tunica intima – innermost, includes the endothelium - squamous cells  Tunica media – middle, mainly circular smooth muscle and elastin  Tunica adventitia –fibrous connective tissue, rich in collagen and elastin

Question 29

what is peripheral resistance?

Answer 29

the resistance of the arteries to blood flow

Question 30

what affects total peripheral resistance?

Answer 30

arteriolar radius and blood viscosity

Question 31

what affects resistnce?

Answer 31

vasodilation and vasoconstriction

Question 32

facts about the capillaries?

Answer 32

- 5% of the blood | - exchange nutrients and metabolic products

Question 33

what are the 4 methods of capillary exchange?

Answer 33

* Diffusion – concentration gradients-- water filled channels (ions) * Vesicletransport(someproteins) * Bulk Flow – blood pressure vs osmosis – protein free plasma * Excess tissue fluid collected by lymph glands

Question 34

what type of resistance and pressure does veins have?

Answer 34

low resistance and pressure

Question 35

why are arteries elastic?

Answer 35

can stretch as increase of BP