The Heart

Question 1

what keeps the blood in motion

Answer 1

the heart

Question 2

4 chambers of heart

Answer 2

2 atria

2 ventricles

Question 3

2 circuits of heart

Answer 3

pulmonary

systemic

Question 4

which ventricle pumps blood to lungs

Answer 4

right

Question 5

what transports blood away from the heart

Answer 5

arteries

Question 6

vessels that interconnect arteries and veins

Answer 6

capillaries

Question 7

what surrounds the heart

Answer 7

pericardium

Question 8

2 layers of the pericardium

Answer 8

outer = fibrous pericardium
inner = serous pericardium

Question 9

inner serous pericardium layers

Answer 9

epicardium (visceral layer)

outer parietal layer

Question 10

space between 2 serious layers

Answer 10

pericardial cavity filled with pericardial fluid

Question 11

purpose of pericardial fluid

Answer 11

lubrication = reduces friction

Question 12

3 layers of the wall of the heart

Answer 12

epicardium = external
myocardium
endocardium = internal, endothelial

Question 13

what does the myocardium consist of, what does it do

Answer 13

cardiac tissue

pumps the heart through rhythmic contraction + relaxation of this layer

Question 14

ventricle muscles are thicker than atrial and on the left side because

Answer 14

left ventricle pumps blood to the entire body

Question 15

cardiac muscle has a ____ appearance

Answer 15

striated

Question 16

cardiac muscle is dependent on

Answer 16

aerobic respiration- lots of mitochondrian and myoglobin

Question 17

do cardiac muscle cells require CNS information

Answer 17

no

Question 18

what connects CMC

Answer 18

intercalated discs

Question 19

cells are bound together by

Answer 19

desmosomes

Question 20

what locks CMC together during contraction

Answer 20

desmosomes

Question 21

what binds the myofibrils of adjacent cells together

Answer 21

intercalated discs

Question 22

CNC are connected into a functional syncytium by

Answer 22

gap junctions

Question 23

ability to generate own rhythm

Answer 23

autorhythmicity

- the heart’s contractile activity is myogenic

Question 24

2 types of autorhythmic cells

Answer 24

pacemaker cells

conduction fibers

Question 25

what cells in the heart generate AP

Answer 25

pacemaker cells

Question 26

the pacemaker cells of the myocardium are located

Answer 26

sinoatrial node = pacemaker of the heart | atrioventricular node

Question 27

where are conduction fibers of the heart found

Answer 27

internodal pathways bundle of HIS purkinje fibers

Question 28

how to determine which cells set the heart rhythm

Answer 28

fastest cells = pacemaker

Question 29

coordination of heart by

Answer 29

gap junctions

Question 30

gap junctions and desmosomes are part of the

Answer 30

intercalated disc

Question 31

signal from SA to AV by

Answer 31

internodal pathway

Question 32

signal spread in atrial muscles by

Answer 32

interatrial pathways

Question 33

what transmit impulses to the rest of the myocardial cells

Answer 33

purkinje fibers

Question 34

5 phases of electrical activity in the heart (ion permeability)

Answer 34

0: increased perm to Na+ 1: decreased perm to Na+ 2: increased perm to Ca2+, decrease to K+ 3: increased perm to K+, decrease Ca2+ 4: resting membrane potential

Question 35

5 phases of heart electrical activity

Answer 35

``` depolarization brief repolarization plateau repolarization rest ```

Question 36

impulses from the ___ can modify SA pacemaker activity

Answer 36

ANS

Question 37

ANS innervates the

Answer 37

SA node AV node cardiac cells smooth muscles of cardiac blood vessels

Question 38

NE from the SNS causes

Answer 38

increase in HR and force of contractions by acting on beta adrenoceptors on nodal and contractile cells

Question 39

ACh from the PNS causes

Answer 39

decrease in HR and force of contractions | activate muscarinic receptors on nodal and contractile cells

Question 40

what centers in the MO can modify heart rate

Answer 40

cardioacceleratory center- sympathetic = increase HR cardioinhibitory center- parasympathetic = lower HR

Question 41

what conducts from the AV node to the apex of the heart

Answer 41

bundle of his or the AV bundle

Question 42

the bundle of his does what going down to the apex

Answer 42

branches into L and R bundle branches