Chapter 21-The Cardiovascular System: The Heart Flashcards Preview

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Flashcards in Chapter 21-The Cardiovascular System: The Heart Deck (36)
1

introduction to the heart

-vital for survival
-carries oxygen and nutrients to tissues
-carries wastes away from tissues
-closed system

2

double circuit of the heart

pulmonary
--heart to lungs and back
--oxygenates blood
systemic
--heart to body and back
-delivers oxygen to tissues

3

structure of heart

-cone shaped
-inside pericardial cavity
-inside mediastinum
-apex tipped toward the inferior and left
-base superior

4

membranes of the heart

pericardium
epicardium
myocardium
endocardium

5

pericardium

-double serous membrane with fibrous coat
-made of several layers
--parietal pericardium:
---outer layer of sac
---fibrous and areolar layer
--epicardium:
---aka visceral pericardium
---inner layer of sac
---adheres to the heart wall
-pericardial cavity:
--between layers
--contains serous fluid

6

epicardium

-visceral pericardium
-functions as protective outer layer

7

myocardium

middle layer
-responsible for contractions
-made of cardiac muscle

8

endocardium

-inner layer
-lines and protects chambers and valves
-continuous with endothelium of heart blood vessels

9

cardiac muscle tissue

-striated
-aerobic respiration
-short t-tubules
-autorhythmic
-connected mechanically and chemically
--intercalated discs
--gap junctions

10

chambers

4 chambers
-2 atria
-2 ventricles

11

2 atria

-superior chambers
-receive blood from veins
-have auricles
--flaps where blood pools

12

2 ventricles

-inferior chambers
-force blood out to arteries
-structural differences:
--left thicker and stronger
--right goes only to lungs
--left is round
--right pouch shaped

13

valves

atrioventricular
-tricuspid
-bicuspid (mitral) valve

14

tricuspid valve

-right AV valve
-at right atrioventricular orifice
-open when atrial force is greater and closed when ventricular force is greater
-3 cusps

15

bicuspid (mitral) valve

left AV valve
-at left atrioventricular orifice
-2 cusps

16

chordae tendonae

-heart strings
-hold valves in place
-attached to cusps on ventricle side
-prevents
--cusps from collapsing into atria when valve is closed
-backflow of blood

17

papillary muscles

-small bundles of mucles
-attache to the chordae tendonae
-when valve closed, these muscles contract and tighten cords

18

trabeculae carneae

-scaffolding on interior walls

19

vlaves

semilunar valves: between ventricle and artery
-pulmonary valve
-aortic valve

20

pulmonary valve

-right
-at entrance to pulmonary trunk
-opens when right ventricle contracts

21

aortic valve

-left
-at entrance to aorta
-opens when left ventricle contracts

22

path of blood

-right atrium: receives blood from superior and inferior vena cava plus coronary sinus
-right av valve
-right ventricle
--conus artiosus: funnel leading from right ventricle to pulmonary trunk
-pulmonary valve
-pulmonary trunk
--goes to lungs
-left atrium
--receives blood from pulmonary veins
-left av valve
-left ventricle
-aortic valve
-aorta
--to tissues

23

coronary circulation

-supplies the heart tissues with blood
-blockage can result in a heart tissue dying

24

coronary arteries

-branch directly off of the aorta as it emerges
-left coronary artery
-right coronary artery

25

left coronary artery

-circumflex artery
-anterior interventricular artery

26

right coronary artery

-posterior interventricular artery
-marginal artery

27

cardiac veins

-drain myocardium
-travel with arteries
-cardiac veins:
--great
--middle
--small
-coronary sinus
--empties into right atrium

28

cardiac cycle

-systole= contractile phase; empties chamber
-diastole= relaxation phase; chambers fill
-heart sounds
--lub= av valves close
--dub=semi-lunar valves

29

conduction system of heart

-heart beat enabled by:
-nodal cells: specialized muscle cells taht conduct action potentials
-conducting fibers: distributes stimulus to myocardium
-aps move down heart, causing it to contract unevenly
--atria contract before ventricles
-5 step process

30

SA node

sinoatrial node
-pacemaker
-spontaneously depolarizes
-at back of wall of right atrium

31

av node

av node (atrioventricular)
-where 4 chambers meet
-signal transmitted to av node through internodal pathways

32

av bundle

transmits down interventricular septum

33

bundle branches

-branch off the av bundle
-moves further down the septum
-one supplies each ventricle

34

purkinje fibers

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

35

ECG/EKG

-electrocardiogram
-P wave: depolarization of atria
-QRS: depolarization of ventricle
-T-wave: repolarization of ventricle
-cardiac output: 5L/min

36

autonomic control

-autorhythmicity: spontaneous contractions
-chemical control: NE and E: increase rate and force
-neural control in medulla
--cardioacceleratory centers: release NE/increase HR
--cardioinhibitory centers: release Ach/decrease HR