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Human Anatomy & Physiology 2 > Heart > Flashcards

Flashcards in Heart Deck (43):
1

What are the 2 major divisions of the heart?

pulmonary
systemic

2

pulmonary circuit (3)

right side of the heart
carries blood to lungs
lower pressure

3

systemic circuit (3)

left side of the heart
carries blood to the rest of the body
higher pressure

4

pericardium

double layered sack surrounding the heart that allows the heart to beat without friction

5

what are the 3 layers of the pericardium?

parietal pericardium
visceral pericardium (epicardium)
pericardial cavity

6

parietal pericardium

outer, tough layer

7

visceral pericardium (epicardium)

inner, thin, smooth
covers the heart surface

8

myocardium

electrical nonconductor; muscles and valves attach to this

9

endocardium

smooth inner lining of the heart; what blood is touching

10

structure of cardiac muscle (3)

short, branched cells
fewer SR
intercalated discs that have electrical junctions

11

What are 3 things needed for the cardiac muscle to be almost exclusively aerobic?

rich in myoglobin
large # of mitochondria
large glycogen storage

12

left and right atria

receive blood returning to the heart

13

left and right ventricle

pump blood into arteries

14

atrioventricular valves right? left?

right=tricuspid
left=bicuspid

15

cords connect AV valves to papillary muscles

chordae tendineae "heart strings"

16

semilunar valves

control flow into great arteries

17

characteristics of the heartbeat? (3)

myogenic:electrical activity
autorhythmic
spread of electrical activity follows a particular pathway

18

myogenic

electrical activity of heartbeat originates with heart

19

autorhythmic

each cell in heart can spontaneously depolarize and contract

20

SA node (2)

pacemaker, initiates heartbeat
contains cells that are fastest to spontaneously depolarize

21

_____ and _____ are electrically isolated

atria and ventricles

22

steps for conduction of heartbeat?

SA node-> AV node->AV bundles(via septum)->purkinje fibers (via moderator band)

23

cardiodynamics

movements and forces generated during the cardiac cycle

24

Cardiac Output=

Heart Rate * Stroke Volume

25

What is the cardiac output at rest? what does it increase to once there is an increase in CO2?

5L/min; 21L/min

26

cardiac reserve

difference between a persons max and resting CO

27

when does the cardiac reserve increase?decrease?

with fitness; disease

28

what changes cardiac output?

changes in heart rate and stroke volume

29

stroke volume=

EDV- ESV

30

What are factors that affect the ESV of stroke volume? (3)

preload
contractibility
afterload

31

What are factors that affect the EDV of stroke volume?

ventricular filling time->faster HB->reduces filling time
venous return

32

Anything that increases blood volume, then ___ ___ increase

venous return

33

preload (ESV)

degree of muscle stretch before contraction

34

the more blood in the ventricle before contraction, the greater the _____ on the ventricle. The more ____ the longer the ____ can _____

stretch; stretch, filament;slide

35

what is responsible for stretching the heart?

blood

36

contractibility (ESV)

amount of force produced during a contraction at a given preload

37

During contractibility, the increasing amount of ____ ___ in the cardiocytes allows for more sliding filaments

free calcium

38

What factors control contractibility? (4)

ANS
hormones
drugs
ion concentration

39

afterload

the force the contraction ventricle must exceed before blood can be ejected

40

A ____ afterload increases ____ and decreases ___

higher; ESV;SV

41

When is afterload increased? (4)

constriction of peripheral blood vessels
circulatory blockage
high blood pressure
valve stenosis

42

tachycardia

resting adult HR above 100

43

bradycardia

resting adult HR below 60