Chapter 21-The Cardiovascular System: The Heart Flashcards Preview

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

introduction to the heart

A
  • vital for survival
  • carries oxygen and nutrients to tissues
  • carries wastes away from tissues
  • closed system
2
Q

double circuit of the heart

A
pulmonary
--heart to lungs and back
--oxygenates blood
systemic
--heart to body and back
-delivers oxygen to tissues
3
Q

structure of heart

A
  • cone shaped
  • inside pericardial cavity
  • inside mediastinum
  • apex tipped toward the inferior and left
  • base superior
4
Q

membranes of the heart

A

pericardium
epicardium
myocardium
endocardium

5
Q

pericardium

A
  • 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
Q

epicardium

A
  • visceral pericardium

- functions as protective outer layer

7
Q

myocardium

A

middle layer

  • responsible for contractions
  • made of cardiac muscle
8
Q

endocardium

A
  • inner layer
  • lines and protects chambers and valves
  • continuous with endothelium of heart blood vessels
9
Q

cardiac muscle tissue

A
  • striated
  • aerobic respiration
  • short t-tubules
  • autorhythmic
  • connected mechanically and chemically
  • -intercalated discs
  • -gap junctions
10
Q

chambers

A

4 chambers

  • 2 atria
  • 2 ventricles
11
Q

2 atria

A
  • superior chambers
  • receive blood from veins
  • have auricles
  • -flaps where blood pools
12
Q

2 ventricles

A
  • 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
Q

valves

A

atrioventricular

  • tricuspid
  • bicuspid (mitral) valve
14
Q

tricuspid valve

A
  • right AV valve
  • at right atrioventricular orifice
  • open when atrial force is greater and closed when ventricular force is greater
  • 3 cusps
15
Q

bicuspid (mitral) valve

A

left AV valve

  • at left atrioventricular orifice
  • 2 cusps
16
Q

chordae tendonae

A
  • 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
Q

papillary muscles

A
  • small bundles of mucles
  • attache to the chordae tendonae
  • when valve closed, these muscles contract and tighten cords
18
Q

trabeculae carneae

A

-scaffolding on interior walls

19
Q

vlaves

A

semilunar valves: between ventricle and artery

  • pulmonary valve
  • aortic valve
20
Q

pulmonary valve

A
  • right
  • at entrance to pulmonary trunk
  • opens when right ventricle contracts
21
Q

aortic valve

A
  • left
  • at entrance to aorta
  • opens when left ventricle contracts
22
Q

path of blood

A
  • 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
Q

coronary circulation

A
  • supplies the heart tissues with blood

- blockage can result in a heart tissue dying

24
Q

coronary arteries

A
  • branch directly off of the aorta as it emerges
  • left coronary artery
  • right coronary artery
25
Q

left coronary artery

A
  • circumflex artery

- anterior interventricular artery

26
Q

right coronary artery

A
  • posterior interventricular artery

- marginal artery

27
Q

cardiac veins

A
  • drain myocardium
  • travel with arteries
  • cardiac veins:
  • -great
  • -middle
  • -small
  • coronary sinus
  • -empties into right atrium
28
Q

cardiac cycle

A
  • systole= contractile phase; empties chamber
  • diastole= relaxation phase; chambers fill
  • heart sounds
  • -lub= av valves close
  • -dub=semi-lunar valves
29
Q

conduction system of heart

A
  • 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
Q

SA node

A

sinoatrial node

  • pacemaker
  • spontaneously depolarizes
  • at back of wall of right atrium
31
Q

av node

A

av node (atrioventricular)

  • where 4 chambers meet
  • signal transmitted to av node through internodal pathways
32
Q

av bundle

A

transmits down interventricular septum

33
Q

bundle branches

A
  • branch off the av bundle
  • moves further down the septum
  • one supplies each ventricle
34
Q

purkinje fibers

A
  • reflect up external wall of ventricle

- extend into papillary muscles

35
Q

ECG/EKG

A
  • electrocardiogram
  • P wave: depolarization of atria
  • QRS: depolarization of ventricle
  • T-wave: repolarization of ventricle
  • cardiac output: 5L/min
36
Q

autonomic control

A
  • 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