Section 4: Cardiology

Question 1

12 major structures of heart

Answer 1

vena cavae
right atrium
tricuspid valve
right ventricle
pulmonary valve
pulmonary artery
lung
pulmonary vein
left atrium
bicuspid (mitral)
left ventricle
aorta

Question 2

Syncytium

Answer 2

contractile myocites function as a single unit

Question 3

autorhythmic cells (3)

Answer 3

specialised excitatory cells
SA node
AV node
Purkinje fibres

Question 4

Desmosome

Answer 4

adhesion between two cells

Question 5

Gap Junction

Answer 5

channel between cells

allows for faster depolarization

Question 6

angina pectoris

Answer 6

severe chest pain due to cardiac ischemia, generally due to obstruction of coronary arteries

Question 7

Heart attack (MI)

Answer 7

cardiac cell death by failure of coronary circulation

Question 8

effects of nitroglycerin

Answer 8

Nirtoglycerin generates NO, which stimulates vasodilation

Question 9

action potential of cardiac myocite duration

Answer 9

approx 300ms

Question 10

puropse of long refractory period of myocyte

Answer 10

prevents sumation, prevents rigor

Question 11

SA node frequency

Answer 11

75BPM

Question 12

AV node frequency

Answer 12

50 BPM

Question 13

AV bundle and purkinjie fibres frequency

Answer 13

25-40

Question 14

Traditional EKG readouts:

3

Answer 14

I) arms
II) Right arm / left leg
III) Left arm / left leg

Question 15

EKG peaks

Answer 15

P
QRS complex
T

Question 16

P wave

Answer 16

Atrial depolarization

Question 17

QRS complex

Answer 17

Ventricular depolarization

Question 18

T wave

Answer 18

Ventricular repolarization

Question 19

Organelle that stores Ca2+

Answer 19

Sarcoplasmic reticulum

Question 20

10 steps tp EC coupling in cardiac muscle

Answer 20

1) Action potential from adjacent cell
2) Voltage gated (L type) calcium channel opens
3) Calcium causes calcium release from SR via ryanodine receptor (RyR)
4) Local release cause Ca spike
5) Spike causes Ca signal
6) Ca causes troponin activation
7) Relaxation occurs when Ca unbinds from troponin
8) Ca is pumped back into SR
9) Ca is eschanged with Na by NCX transporter
10) Na+ gradient is maintained with Na/K ATPase

Question 21

L type sodium channel

Answer 21

lets Na into cardiomyocyte

Question 22

Ryanodine Receptor (RyR)

Answer 22

allows calcium out of SR

Question 23

SERCA

Answer 23

pulls Ca back into SR

Question 24

Beta adrenergic stimulation causes

Answer 24

increase in L type Ca channels, RyR receptors, and SERCA

Question 25

1 heart noise

Answer 25

Lub

caused by AV valves closing due to increased ventricular pressure

Question 26

Beta agonists

Answer 26

Epinephrine, norepinephrine

Question 27

effect of beta agonists

Answer 27

hyperpolarize (activate) pacemaker channels (funny channels)

Question 28

acetylcholine binds to

Answer 28

muscarinic receptors

Question 29

Frank-Starling Law

Answer 29

stroke volume is proportional to blood volume in right atrium