Cardiovascular - lecture 1 Flashcards
what is pericarditis?
inflammation of the pericardium
pericarditis roughens membrane surface causing ___________ which sounds like _________.
pericardial friction rub
creaking
what is cardiac tamponade?
excessive fluid that leaks into pericardial space
cardiac tamponade can _______ the heart’s _______________.
compress
pumping ability
what are the three layers of heart wall?
epicardium
myocardium
endocardium
epicardium is the _______ layer of ____________________.
visceral
serous pericardium
what are the two parts of the epicardium?
parietal
visceral
myocardium is _________ or _________ bundles of ________ and ______ muscles
circular or spiral
contractile and non-contractile
endocardium is the __________ layer; is _________ with _______ lining of blood vessels
innermost
continuous
endothelial
endocardium lines _________ and covers _________ of valves
heart chambers
cardiac skeleton
what do heart valves ensure?
unidirectional blood flow through heart
heart valves ______ and ______ in response to _________________.
open
close
pressure changes
what are the two major types of valves?
atrioventricular valves
semilunar valves
atrioventricular valves are located between . . .
atria and ventricles
atrioventricular valves are split into what two valves?
tricuspid valve
bicuspid valve
semilunar valves located between . . .
ventricles
major arteries
the steps when the AV valves are opening:
- blood returning to the heart fills atria, pressing against the AV valves. the increased pressure forces AV valves open
- as ventricles fill, AV flaps hang limply into ventricles
- atria contract, forcing additional blood into ventricles
AV valves open; atrial pressure is _________ than ventricular pressure
greater
the steps when the AV vales are closing:
- ventricles contract, forcing blood against AV valve cusps
- AV valves close
- papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria
semilunar valves open as . . .
ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves forcing them to open
semilunar valves close as . . .
ventricles relax & intraventricular pressure falls, blood flows back from arteries, filling the cusps of semilunar valves and forcing them to close
two conditions that severely weaken the heart:
imcompetent valve
valvular stenosis
incompetent valve is when . . .
blood backflows so the heart repumps same blood over and over
example of incompetent valve is . . .
mitral regurgitation
valvular stenosis is . . .
stiff flaps that constrict the opening; this requires the heart to exert more force to pump blood
blood flow through the RIGHT side of the heart:
SVC, IVC & coronary sinus
right atrium
tricuspid valve
right ventricle
pulmonary semilunar valve
pulmonary trunk
pulmonary arteries
lungs
blood flow through the LEFT side of the heart:
four pulmonary veins
left atrium
mitral valve
left ventricle
aortic semilunar valve
aorta
systemic circulation
blood from the LEFT side of the heart ends up at the . . .
whole body
blood from the RIGHT side of the heart ends up at the . . .
lungs
RIGHT side of the heart receives ________ blood & gets rid of ________
unoxygenated blood
CO2
LEFT side of the heart receives ________ blood
oxygenated
anatomy of the heart - LEFT SIDE (top to bottom)
aorta
left pulmonary artery
left atrium
left pulmonary veins
mitral (bicuspid) valve
aortic valve
pulmonary valve
left ventricle
papillary muscle
interventricular septum
epicardium
myocardium
endocardium
anatomy of the heart - RIGHT SIDE (top to bottom)
superior vena cava
right pulmonary artery
pulmonary trunk
right atrium
right pulmonary veins
tricuspid valve
right ventricle
chordae tendineae
inferior vena cava
the right ventricle has _______ wall than left ventricle
thinner
what shape is the right ventricle ?
crescent shape
the right ventricle _____ around left ventricle
wraps
the left ventricle has _______ wall than right ventricle
thicker
what shape is the left ventricle ?
round shape
what are the 2 coronary arteries ?
left coronary artery
right coronary artery
the LEFT coronary artery supplies blood to where ?
interventricular septum
anterior ventricular wall
left atrium
posterior wall of left ventricle
what are the 2 branches of the LEFT coronary artery ?
anterior interventricular artery
circumflex artery
the RIGHT coronary artery supplies blood to where ?
right atrium and most of right ventricle
what are the 2 branches of the RIGHT artery ?
right marginal artery
posterior interventricular artery
angina pectoris is ________ caused by _____________ to _________________.
thoracic pain
fleeting deficiency in blood delivery
myocardium
angina pectoris causes the ________ of cells and leads to _______________.
weakening
myocardial infarction
areas of cell death are repaired with . . .
noncontractile scar tissue
fatal heart attack can occur with 100% blockage of . . .
1) left main coronary
2) proximal left anterior descending (LAD) artery — widow maker artery
SIMILARITIES of skeletal and cardiac muscles
- both are contractile tissues
- both types of muscle contraction are preceded by depolarization in the form of an action potential (AP)
- both require the sarcoplasmic reticulum (SR) to release calcium (Ca2+)
DIFFERENCES of skeletal and cardiac muscles
- some cardiac muscle cells are self-exictable
- the heart contracts as a unit
- special Ca2+ channel
- no tetanic contractions in cardiac muscles
- cardiac muscle must have aerobic respiration
what are the 2 kinds of myocytes in cardiac muscle ?
contractile cells
pacemaker cells
what are contractile cells responsible for?
contraction
what are pacemaker cells and what do they do?
noncontractile cells that spontaneously depolarize
what do pacemaker cells initiate?
depolarization of the entire heart
pacemaker cells do NOT need ____________ stimulation
nervous system
the proper of having pacemaker cells is _________ or ____________.
automaticity or autorhythmic
all cardiomyocytes contract as a _______ or ______________.
unit
none contract
desmosomes prevent . . .
adjacents cells from separating during contraction
gap junctions allow . . .
ions to pass from cell to cell, transmitting current across the entire heart
contraction of all cardiac myocytes ensures what ?
effective pumping action
skeletal muscles contract . . .
independently
in skeletal muscle the wave of depolarization directly cause . . .
the release of ALL of the Ca2+ required for contraction
in cardiac muscle depolarization opens . . .
special Ca2+ channels in the plasma membrane
depolarization opens ________________ allowing _______ of Ca2+ needed for contraction
slow Ca2+ channels
10-20%
Ca2+ triggers _________________ in the SR to release a burst of Ca2+ ( _________ needed for contraction)
Ca2+ sensitive channels
80-90%
cardiac muscle fibers have longer ___________ than skeletal muscle fibers
refractory period
____________ is almost as long as ________ itself
absolute refractory period
contraction
absolute refractory period prevents ________________.
tetanic contractions
absolute refractory period allows the heart to _____ and _____ as needed to be an efficient pump
relax and fill
cardiac muscle has more ________ than skeletal muscle so has greater ___________________.
mitochondria
dependence on oxygen
skeletal muscle can go through _________ when oxygen is ________________.
fermentation
not present
cardiac muscle ___________ function without oxygen
cannot
cardiac is more ________ to other fuels, including ___________, but must have __________.
adaptable
lactic acid
oxygen
where are pacemaker cells found?
SA node
the steps of action potential initiation by pacemaker cells
- pacemaker potential
- depolarization
- repolarization
Pacemaker potential
slow depolarization is due to both opening of Na+ channels and closing of K+ channels
** notice that the membrane potential is NEVER a flat line
Depolarization
the action potential begins when the pacemaker potential reaches threshold.
** depolarization is due to Ca2+ influx through Ca2+ channels
repolarization
is due to Ca2+ channels inactivating and K+ channels opening. this allows K+ efflux, which brings membrane potential back to its most negative voltage
Sequence of excitation
- the sinoatrial (SA) node (pacemaker) generates impulses — 72-75 bpm
- the impulses pause (0.1s) at the atrioventricular (AV) node — 50 bpm
- the atrioventricular (AV) bundle connects the atria to the ventricles
- the bundle branches conduct the impulses through the interventricular septum
- the subendocardial conducting network depolarizes the contractile cells of both ventricles
defects in the intrinsic conduction system may cause:
arrhythmias
fibrillation
arrhythmias
irregular heart rhythms which is uncoordinated atrial and ventricular contractions
fibrillation
rapid, irregular contractions
treatment for fibrillation
defibrillation
a defective SA node may cause ____________.
ectopic focus
ectopic focus is an . . .
excitable group of cells that cause a premature heartbeat
extrasystole is a . . .
premature contraction of the heart that is independent of the normal heart rhythm
extrasystole occurs in response to an . . .
ectopic foci
to reach ventricles, impulse must pass through . . .
AV node
if AV node is defective may cause a . . .
heart block
ventricles beat at their own . . .
intrinsic rate
heartbeat modified by ______ via _______________ in the ______________________.
ANS
cardiac centers
medulla oblongata
cardioacceleratory center sends signals through ______________ to increase both _________________.
sympathetic trunk
rate and force
cardioacceleratory center stimulates . . .
SA and AV nodes, heart muscle, & coronary arteries
cardioinhibitory center sends ____________________ via ____________ to decrease ________.
parasympathetic signals
vagus nerve
rate
cardioinhibitory center inhibits . . .
SA and AV nodes via vagus nerves
P wave
depolarization of SA node and atria
QRS complex
ventricular depolarization & atrial repolarization
T wave
ventricular repolarization
P-R interval
beginning of atrial excitation to beginning of ventricular excitation
S-T segment
entire ventricular myocardium depolarized
Q-T interval
beginning of ventricular depolarization through ventricular repolarization
systole
period of heart contraction
diastole
period of heart relaxation
cardiac cycle
blood flow through heart during one complete heartbeat
atrial systole and diastole are followed by . . .
ventricular systole and diastole
mechanical events of heart
- ventricular filling: mid-to-late diastole
- isovolumetric contraction
- ventricular ejection
- isovolumetric relaxation: early diastole
in ventricular filling: mid-to-late pressure is _____.
_______ of blood passively flows from ______ through ___________ into _______ (SL valves closed)
low
atria
open AV valves
ventricles
atrial depolarization triggers _________ and ___________
atrial systole and atria contract
end diastolic volume (EDV)
volume of blood in each ventricle at the end of ventricular diastole
isovolumetric contraction is when the ____________ and __________________.
atria relax and ventricles begin to contract
rising of ventricular pressure causes . . .
closing of AV valves
isovolumetric contraction phase is split-second period when ventricles are . . .
completely closed, volume remains constant, ventricles continue to contract
when ventricular pressure exceeds pressure in large arteries, SL valves are. . .
forced open
end systolic volume (ESV)
volume of blood remaining in each ventricle after systole
ventricular pressure drops causing backflow of blood from ______ and pulmonary trunk that triggers closing of __________.
aorta
SL valves
heart beats around _____ times per minute
75
cardiac cycle lasts about . . .
0.8 seconds
atrial systole lasts about . . .
0.1 seconds
ventricular systole lasts about . . .
0.3 seconds
quiescent period is total heart relaxation that lasts about . . .
0.4 seconds
what sound is the “lub” ?
closing of AV valves at beginning of ventricular systole
what is the “dub” ?
closing of SL valves at beginning of ventricular diastole
mitral valves closes slightly before _________ and aortic closes slightly before _______________.
tricuspid
pulmonary valve
heart murmurs
abnormal heart sounds heard when blood hits obstructions
heart murmurs usually indicate valve problems such as . . .
incompetent valve
stenotic valve
incompetent valve
fails to close completely, allowing backflow of blood
stenotic valve
fails to open completely, restricting blood flow through valve
incompetent valves cause
swishing sounds
stenotic valve causes
high-pitched sound or clicking
