Chapter 14 (Part 3)

Question 1

a premature atrial contraction will be followed by what?

Answer 1

premature ventricular contraction

Question 2

premature atrial contraction will be followed by premature ventricular contraction. so what?

Answer 2

prevents proper filling of heart chambers and therefore, insufficient amount of blood pumped out of the heart

Question 3

what is fibrilation?

Answer 3

loss of coordination of electrical activity of the heart (contractile cells are not synchronized)

Question 4

what are the two types of fibrilation?

Answer 4

atrial and ventricular

Question 5

what ensures directional flow through the heart?

Answer 5

cardiac cycle

Question 6

what’s the big deal with the cardiac cycle?

Answer 6

ensures directional flow through the heart

Question 7

heart valves open passively due to?

Answer 7

pressure

Question 8

all valves closed prevents what?

Answer 8

backflow

Question 9

what is the name of cardiac cycle phase 2?

Answer 9

isovolumetric contraction

Question 10

what is an isovolumetric contraction?

Answer 10

closes AV valves before opening SL valves

Question 11

what is the name of cardiac cycle phase 4?

Answer 11

isovolumetric relaxation

Question 12

what is isovolumetric relaxation?

Answer 12

closes SL valves before opening AV valves

Question 13

some blood is still in the _____ in isovolumetric relaxation?

Answer 13

ventricles

Question 14

what nerve of the PNS acts on SA and AV nodes to lower heart rate?

Answer 14

vagus nerve

Question 15

what nerve of the SNS acts at SA and AV nodes to increase HR and the ventricular myocardium contraction force to increase stroke volume

Answer 15

sympathetic cardiac nerve

Question 16

parasympathetic control slows down heart rate: Ach binds to ____________ G protein coupled receptors that inhibit adenylate cyclase activity

Answer 16

muscarinic cholinergic

Question 17

increasing CO by increasing stroke volume by extrinsic factors. what are they? (3)

Answer 17

• involves the SNS and norepinephrine increases Ca+2 influx through LTCCs
• increases contractile strength of heart = lowers end systolic volume
• NT binds to G ptn coupled receptors = cAMP = PKA = more Ca+2 through L-type Ca+2 channels = more crossbridge formation

Question 18

describe Frank-Starling effect vs. alternate troponin effect?

Answer 18

F-S: with more blood being returned to the heart, heart muscle is stretched more and inherently contracts more forcefully = increase in stroke volume =more blood pumped out

• troponin is altered = binds Ca+2 more readily = displaces more tropomyosin = … more crossbridging and stronger contractions

Question 19

“heart muscle fiber length is not at optimal length.” what does that mean?

Answer 19

cardiac sarcomeres are shorter

Question 20

summary of factors slide

Question 21

nitroglycerin treatment for heart attack causes vasodilation slide

Question 22

how was functional heart muscle regenerated in de-cellularized human hearts

Answer 22

injected the induced pluripotent stem cells into the de-cellularized ventricle