Cardiovascular Mechanics

Question 1

Which scan can be used to see heart contractions?

Question 2

Which ion is needed for heart contraction?

Question 3

What happens to Ca2+ ion concentration to cause a heart contraction?

Question 4

What is the length of ventricular cells?

Question 5

What is the width of ventricular cells?

Question 6

What are T-tubules?

Question 7

What is the size of T-tubules?

Question 8

Where are T-tubules found?

Question 9

What is the function of T-tubules?

Question 10

What proportion of cardiac myocytes are mitochondria?

Question 11

What proportion of cardiac myocytes are myofibrils?

Question 12

What proportion of cardiac myocytes are sarcoplasmic reticulum?

Question 13

What proportion of cardiac myocytes are the nucleus?

Question 14

What is the arrangement of organelles in cardiac myocytes?

Question 15

What surrounds T-tubules?

Question 16

What are ryanodine receptors?

Question 17

What are LTCCs?

Question 18

What are RYRs?

Question 19

What are the 8 steps of excitation-contraction coupling?
(32. F, C, A, H, E, B, G, D)

Question 20

What is excitation-contraction coupling?

Question 21

How does Ca2+ enter cardiac myocytes?

Question 22

What is the pathway of Ca2+ in excitation-contraction coupling?

Question 23

Which 4 transporter proteins are used for Ca2+ in excitation-contraction coupling?

Question 24

What is the relationship between cytoplasmic Ca2+ conc and contraction force?
(graph) - sigmoidal

Question 25

How can muscle force be measured?

Question 26

What is the relationship between cardiac muscle length and contraction force? (graph)

Question 27

What is muscle active force?

Question 28

What is muscle passive force?

Question 29

What is isometric contraction?

Question 30

Draw the muscle length-contraction force graph for total force

Question 31

Draw the muscle length-contraction force graph for active force

Question 32

Draw the muscle length-contraction force graph for passive force

Question 33

Why does cardiac muscle stretch have a limit? (pericardium)

Question 34

What is the difference between resistance and compliance of cardiac vs skeletal muscle?

Question 35

Draw the force graph for skeletal muscle (total, passive, active)

Question 36

Draw the force graph for cardiac muscle (total, passive, active)

Question 37

Why are there differences in the properties of cardiac vs skeletal muscle? (2)

Question 38

What is isometric cardiac contraction?

Question 39

What is isotonic cardiac contraction?

Question 40

What is the stretch-force graph for isometric cardiac contraction?

Question 41

What is a preload vs afterload? (see 18 + 19)

Question 42

What is the relationship between afterload and cardiac muscle shortening and why?

Question 43

What is the stretch-force graph for isotonic cardiac contraction?

Question 44

Which type of load leads to isometric contraction?

Question 44

Which type of load leads to isotonic contraction?

Question 45

What determines the heart preload and why? - venous return

Question 46

What are the 3 measures of preload?

Question 47

What determines the heart afterload and why?

Question 48

What is the diastolic blood pressure in humans? - 80

Question 48

Which condition is very closely related to cardiac complications?

Question 49

What is the measure of afterload?

Question 50

What is the Frank-Starling relationship?

Question 51

Why do ventricles pump a greater stroke volume according to the Frank-Starling relationship?

Question 52

What are the 2 factors contributing to the Frank-Starling relationship?

Question 53

What is TnC?

Question 53

How does myofibril cross-bridge number effect the Frank-Starling relationship?

Question 54

How does calcium sensitivity effect the Frank-Starling relationship?

Question 55

What is the function of TnC?

Question 56

What dictates Ca2+ sensitivity? - affinity of TnC

Question 57

What is stroke work?

Question 58

What is the equation for stroke work?

Question 59

What affects stroke volume? - preload and afterload

Question 60

What affects cardiac pressure?

Question 61

What is the law of LaPlace?

Question 62

Why can the left ventricle generate higher pressure than the right ventricle?

Question 63

What is the equation for LaPlace's law?

Question 64

Why do failing hearts often have increased wall stress?

Question 65

What are the 4 stages of excitation-contraction coupling?

Question 66

Which structures facilitate action potential transmission in excitation-contraction coupling?

Question 67

Which 2 structures are the communication interface in excitation-contraction coupling?

Question 68

Where is calcium stored in muscle cells?

Question 69

Which ion is essential for myofilament contraction?

Question 70

When can the preload of heart muscle be measured?

Question 71

When can the afterload of heart muscle be measured?

Question 72

Which 2 factors affect Starling's law?

Question 73

What type of contraction occurs in the myocardium?

Question 74

Which 2 structures does the law of LaPlace apply to?

Question 75

Why does the heart not rip under high pressures?