Chapter 21: Cardiovascular system and Heart Flashcards Preview

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Flashcards in Chapter 21: Cardiovascular system and Heart Deck (42)
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31

what is the contractile phase; chamber empties

systole

32

what is the relaxation phase; chambers fill

diastole

33

describe what happens when your heart makes the "Lub" and "Dup" sounds

“Lub” = AV valves close
“Dup” = semi-lunar valves close

34

Heart beat is enabled by what 2 things? describe them

1.) nodal cells
-specialized muscle cells that conduct action potentials
2.) conducting fibers
-distributes stimulus to myocardium

35

true or false: AP’s move down heart, causing it to contract unevenly

true
*atria contract before ventricles

36

what are the 5 steps in the conduction system of the heart?

1.) SA node activity and atrial activation begin
2.) Stimulus spreads across the atrial surfaces and reaches the AV node
3.) There is a 100-msec delay at the AV node. Atrial contraction begins
4.) The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibers and, via the the moderator band, to the papillary muscles of the right ventricle
5.) The impulse is distributed by the Purkinje fibers and relayed throughout the ventricular myocardium. Atrial contraction is completed, and ventricular contraction begins

37

describe the SA (sinoatrial) node (3)

pacemaker
spontaneously depolarizes
At the back wall of right atrium

38

describe the AV (atrioventricular) node (2)

-where 4 chambers meet
-Signal transmitted to AV (atrioventricular) node through internodal pathways

39

the AV (atrioventricular) bundle....

transmits down interventricular septum

40

describe bundle branches (3)

Branch off the AV bundle
Moves further down the septum
one supplies each ventricle

41

describe Purkinje Fibers (2)

-reflect up external wall of ventricle
-extend into papillary muscles

42

slide 27 and 28

because I'm lazy and don't know how to make these cards really into flashcards