CV

Question 1

S1

Answer 1

AV valves closing - mitral and tricuspid
Pulmonary and aortic opening
beginning of systole

Question 2

S2

Answer 2

closure of pulmonary and aortic
opening of mitral and tricuspid
beginning of diastole

Question 3

S3

Answer 3

rapid ventricular filling
normal: children, athletes, pregnancy d/t added blood volume, vigorous relaxation of LV

abnormal: all else, often seen in decomposition CHF d/t high LA pressure

Question 4

S4

Answer 4

atria contracting against stiff/noncompliant ventricle
always abnormal
ventricular hypertrophy, scar tissue

Question 5

right border of heart CXR

Answer 5

mostly RA

Question 6

anterior heart CXR

Answer 6

mostly RV

Question 7

RV blood supply

Answer 7

R marginal artery

Question 8

AV node blood supply

Answer 8

PDA

Question 9

posterior walls of ventricles blood supply

Answer 9

PDA

Question 10

anterior LV blood supply

Answer 10

LAD
most commonly occluded

Question 11

lateral and posterior LV blood supply

Answer 11

left circumflex coronary artery

Question 12

LV blood supply

Answer 12

posterior - PDA
anterior - LAD
lateral and posterior - left circumflex

Question 13

LA blood supply

Answer 13

left circumflex

Question 14

SA node blood supply

Answer 14

RCA

Question 15

sympathetic innervation heart

Answer 15

T1-T4/5 spinal nerves/sympathetic trunk

Question 16

lymph drainage heart

Answer 16

tracheobronchial nodes

Question 17

myocarditis causes

Answer 17

US: viral, usually coxsackievirus
South America: Trypanosoma cruzi

Question 18

intercalated discs

Answer 18

fascia adherens (contractility) - desmosomes (structural integrity) - gap junctions (propagation)

Question 19

cell type cardiac impulse generation

Answer 19

nodal cells of SA node

Question 20

β1 activation

Answer 20

By ne
Symp
In sa node Opens Na channels, increasing funny current.
→ increased frequency of spontaneous polarization
Ie. Increased hr
Ca influx in av node → same result - increased hr

Directly on myocytes opens Ca channels, increases Ca pump activity, increases Ca storage → increased hr and contractility

Question 21

Ach in hear t

Answer 21

Para
Muscarinic
Slow Hr
Sa node-closes Na channels, lowers funny current
Av node-closes ca channels, slowing transmission
No direct effect onmyocytes or contractility, unlike ne

Question 22

β2 receptors

Answer 22

Weakly binds to ne
NE → vasodilation @β2
@α1/2 → stronger binding, constricts tf overall vasoconstrictive effect as long as α1/2 are present

Question 23

α1/2 receptors

Answer 23

Strongly bind ne → vasoconstrictor
α blockers Tx hyper tension

Question 24

Connexin

Answer 24

Gap junction proteins- pores

Question 25

Dihydropyridine receptors

Answer 25

Cachannel- extra cellular to intra
Open dt depolarization
Trigger ryanodine receptors to release Ca from sr
Ca-induced Ca release