Heart 2

Question 1

cardiac muscle has more what

Answer 1

mitochondria and electrical connections

Question 2

what is the pace maker of the heart

Answer 2

sinoatrial node (SA)

Question 3

the heart has what type of rythmn

Answer 3

intrinsic

Question 4

where is the back up pacemaker

Answer 4

in the ventricles (AV node)

Question 5

describe the backup pacemaker

Answer 5

slower paced; gets overriden by SA node signal

Question 6

what is the heart’s nervous system

Answer 6

cardiac conduction system

Question 7

what are the 6 steps of the cardiac conduction system

Answer 7

1. SA node fires 2. atria contract 3. atrioventricular node delays signal about .1 sec 4. atrioventricular bundle conducts rapidly 5. bundle branches take signal to apex 6. purkinje fibers

Question 8

in what order does pumping occur

Answer 8

first is the atria then ventricles(inferior to superior)

Question 9

what maximizes efficiency of the heart

Answer 9

the timing of action potentials and pumping

Question 10

what is the heart’s intrinsic rhythm usually slowed by

Answer 10

parasympathetic

Question 11

what is a typical heart rate

Answer 11

75 beats per minute

Question 12

what is the SA node pace slowed by

Answer 12

parasympathetic(specifically acetolcholine)

Question 13

where does sympathetic stimulation flow

Answer 13

brain stem-spinal cord-rib-either SA node, AV node, or left ventricle

Question 14

what cause an increase of heart rate

Answer 14

SA and AV nodes

Question 15

what cause the heart to beat more strongly

Answer 15

left ventricle

Question 16

aka adrenaline

Answer 16

epinephrine

Question 17

this records the composite electrical impulses of the heart (noninvasive)

Answer 17

electrocardiography (ECG)

Question 18

how do ECGs work

Answer 18

they measure thoracic electrical signals(patient must lie still)

Question 19

what is atrial contraction

Answer 19

P wave

Question 20

what is atrial relaxation and ventricular contraction

Answer 20

QRS complex

Question 21

ventricular relaxation/repolarization

Answer 21

T wave

Question 22

what happens when depolarized

Answer 22

atria contract

Question 23

how long does the atria stay contracted

Answer 23

1.5 sec then it relaxes

Question 24

what happens during the ST segment

Answer 24

emptying, squeezed shut and squeezes blood out

Question 25

what happens during ventricular filling

Answer 25

blood flow back into the ventricle; fills it up