CVS physiology

Question 1

Explain the cardiac cycle and the different stages in detail

Answer 1

Question 2

What is part of the cardiac cycle is eliminated when heart rate increases for exercise?

Answer 2

Slow filling and slow ejection

Question 3

Explain calcium induced calcium release?

Answer 3

Question 4

Explain cardiac muscle relaxation (referring to the calcium reuptake).

Answer 4

Question 5

What mechanisms of sympathetic stimulation of the heart makes it more contractile

Answer 5

Question 6

Explain starlings law?

How does this compare to contractility?

Answer 6

Question 7

What happens to the starling curve with myocardial infarction?

What compensatory mechanims ensue.

Answer 7

Question 9

Explain the SA node membrane potential cycle

Answer 9

Question 10

What causes the heart rate to differ from the pacemaker natural depolarisation rate?

Answer 10

Question 11

Explain the excitation system (the flow from start to end).

What are the speeds through each of the systems?

Answer 11

Myocardium

• Contains gap junctions which pass electrical signal via the intercalated discs, this causes a functional syncytium.
• Conduction through atria 0.5m/s, AV node 0.05m/s, bundle of his, bundle branches and purkinje fibres 5m/s, ventricle muscle 0.5m/s.

Question 13

Ventricular muscle cell action potential.
Explain each of the phases.

Answer 13

Question 14

Explain why it is important that electrical and mechanical activity overlap

Answer 14

Question 15

What is the law of resistance and what vessels is it important with?

Answer 15

Question 16

Why are hardened arteries bad?

Explain this storage of energy in normal arteries?

Answer 16

Question 17

What are the different intrinsic and extrinsic controls to vascular tone?

Answer 17

Question 18

What is reactive vs active hyperemia?

Answer 18

Question 19

What are the paracrine systems? give examples

Answer 19

Question 20

Explain the extrinsic nervous system control of venous pressure?

Answer 20

Question 21

Hormonal extrinsic control of vasculature?

Answer 21

Question 22

What are the 3 classes of capillaries?

Answer 22

Question 23

What are the two main functions of capillaries?
Explain each

Answer 23

Question 24

Explain starlings equilibrium

Answer 24

Question 25

Using starlings equilibrium explain what would happen with an inflammatory response and during a haemorrhage

Answer 25

Question 26

Answer 26

Question 27

What do each of the coronary arteries supply?

Answer 27

Question 28

Explain the blood supply to the heart during systole and diastole. What happens during exercise? How is this regulated?

Answer 28

Question 29

Explain cerebral circulation and how it is regulated?

Answer 29

Question 30

Explain the blood flow to the skin? What is the main purpose?

Answer 30

Question 31

Explain blood flow to the kidney. How is it regulated?

Answer 31

Question 32

Explain the regulation of splanchnic blood flow?

Answer 32

Question 33

How much oxygen does the heart have to extract from the blood that it gets? What is the major stimuli for increasing blood flow to the heart?

Answer 33

Question 34

How much stenosis must occur before symptoms occur in the heart? Why can severe stenosis lead to a downward spiral of symptoms?

Answer 34

Question 35

Explain the spread of extracellular K+ and its effects on an ischemic heart?

Answer 35

Question 36

What would you see on an ECG with and STEMI and why?

Answer 36

Question 37

What is chronic cardiac failure?

Answer 37

Inability of the heart to maintain adequate perfusion at normal filling pressure

Question 38

What happens on the starling curve with cardiac failure? How is this compensated for?

Answer 38

Question 39

What is ejection fraction and how does this differ with heart failure? Plus exercise?

Answer 39

Question 40

Cardiovascular variables, comparison of normal heart vs with heart failure. How does this change with exercise?

Answer 40

Question 41

What are the two main compensations that occur with cardiac failure?

Answer 41

Question 42

Why does oedema occur with heart failure? Peripheral vs pulmonary

Answer 42

Question 43

Law of Laplace. How does this relate to heart failure?

Answer 43

Question 44

Problems facing the failing heart? How do you treat heart failure?

Answer 44