cardiac electrophysiology

Question 1

types of cardiac cells

Answer 1

pacemaker or non

Question 2

pacemaker cell info

Answer 2

specialized myocardial cells, in SA/AV nodes,/ his/perk.. Dif patterns, auto rhythmic

Question 3

3 sections of pacemaker AP

Answer 3

phase 4 depol, depol, repol

Question 4

phase 4 depol

Answer 4

pacemaker potential. slow rise to threshold, decreased K efflux, if current, gradual ca influx= net positive

Question 5

if current

Answer 5

slow Na influx (non spec/leaky

Question 6

depol pacemaker

Answer 6

voltage gated ca2+ efflux (dom inward current)

Question 7

repol pacemaker

Answer 7

volt gated K+ efflux

Question 8

nervous control of pacemaker parasympha:

Answer 8

ACH to av node, decrease If, decrease ca in phase 4

Question 9

nervous control of pacemaker sympha:

Answer 9

cardiac plexus, norepinephrine, increase If/ca in phase 4, decrease threshold to more neg

Question 10

non pacemaker cell info

Answer 10

not autorhythmic, 5 phase

Question 11

stages non pacemaker Ap

Answer 11

0: Na influx/voltage gated. 1: inactivate na, 2: plate, open ca in, close K out, 3: ca2+ channels close, k efflux, 4: resting pot (small k/ na)

Question 12

refractory absolute for non pacemaker

Answer 12

0-part of 3, na channel are inactive. allows time for heart to refill ( no tetany)

Question 13

conduction of AP between cells

Answer 13

gap junctions, low R ion channel, spread of depol,