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Flashcards in heart Deck (32):
1

discuss the cardiac cycle?

the route that a drop of blood takes throughout the heart.
1. vena cava-r. atrium-av valve-r. ventricle-pulmonary semilunar valve-pulmonary circulation
2. pulmonary veins-L. atrium-mitral valve-l. ventricule-aortic semilunar valve- aorta- body tissues.

2

how the heart cells unique from other tissues?

have the ability to automatically depolarize.

3

automaticity mean?

heart can work on its own

4

functional syncyctium?

all parts of the heart operate in coordinated motion to move blood.

5

what is the 2 most important functions of the heart?

1. automaticity
2. functional syncyctium

6

name the intrinsic conduction system?

1. SA node
2. intermodal pathway
3. av node
4. av bundle +bundle branches
5. pukinje fibers

7

what is the pacemaker of the heart?

sa node

8

what iniates contraction of the atrium?

the internodal pathway

9

what is the role of the av node

delay electrical info. so ventricles can fill

10

what sends electrical signals to the bottom of the heart?

av bundle (send to apex)

11

what stimulates the ventricle cardiac muscles to contract (contractor)

pukinje fibers

12

what is polarization?

opposite ends

13

depolarize

what ends mix (mixing of charges) . the trigger for actions to occur

14

where do you see membrane potential?

in excitory cells. create a difference of charge in cells.

15

why can the heart self pace itself?

because of the leaky sodium channels. it can operate outside the nerve influence.

16

name 3 general rules of intrinsic conduction system?

1. if cells are excited, they immediated excite adjacent cells
2. after cells are excited, it requires little amount of time to reset its membranes and cannot be excited during this period (refractory period)
3. if cells are not excited by neighbor, it will spontaneously depolarize but it may take longer for this to occur on its own based on the location of the cell.

17

what builds up when 02 not present?

lactic acid

18

ectopic focus

one are of heart is irritated. ex: a. flutter (becomes pacemaker of heart)

19

ectopic foci (plural)

multiple areas of heart are irritates ex. v. fib

20

cardiac output

amount of blood pump out by each ventricle in one minute. (meet oxygen and nutrient needs of body)

21

formula for cardiac output?

CO= HRX SV

22

stroke volume

measure of the amount of blood per stroke/contraction of the heart.

23

what controls the heart to beat below 100/min?

parasysmpathetic nervous system

24

HR above 100/min cause?

sysmpathetic nervous system.

25

preload

amount of blood in ventricle prior to contractor (how much venous blood return to ventricles

26

frank starling law

more you stretch heart, more harder it contracts

27

contractility

force with which cardiac muscles contract

28

afterload

pressure heart must overcome to deliver blood to ex: aorta (overcome resistance)

29

how many % of americans died of cardiovascular disease?

50%

30

atherosclerosis

hardening of arteries that inhibit blood flow (build up of plaque)

31

why is atherosclerosis bad?

in coronary arteries, it increases risk for ischemia and subesequent arrythmia

32

what is the formula for stroke volume?

difference between end diastolic volume and end systolic volume (SV=EDV-ESV)