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43 terms

A&P 2 Chapter 18

marieb, the heart
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aorta
largest artery in the body;arises from the left ventricle of the heart
atria
the two superior receiving chambers of the heart
atrioventricular (AV) node
specialized mass of conducting cells located at the atrioventricular junction in the heart
atrioventricular (AV) bundle
bundle of specialized fibers that conduct impulses from the AV node to the right and left ventricles; also called bund of his
atrioventricular (AV) valves
valve that prevents backflow into the atrium when the connected ventricle is contracting
bicuspid valve
the left AV valve; 2 flaps
baroreceptors
a sensory nerve ending in the wall of the carotid sinus or aortic arch sensitive to vessel stretching
cardiac output
amount of blood pumped out of a ventricle in one minute
chordae tendineae
tiny white collagen cords attached to AV valves; "heart strings" which anchor the cups to the papillary muscles protruding from the ventricular walls
left coronary artery
runs toward the left side of the heart and then divides into its major branches ;Anterior intraventricular artery & circumflex artery
right coronary artery
courses to the right side of the heart ; branches to Right marginal artery & Posterior interventricular artery
tricupsid valve
3 flaps; the right AV valve
diastole
relaxation period
cardiac cycle
includes all events associated with the blood flow through the heart during one complete heart beat- atrial systole and diastole followed by ventricular systole and diastole
end-diastolic volume (EDV)
the amount of blood that collects in a ventricle during diastole
endocardium
glistening white sheet of endothelium (squamous epithelium) resting on a thin connective tissue layer; lines the heart chambers & covers the fibrous skeleton of the valves
epicardium
most visceral layer of the heart and also an interal part of the heart wall
fibrous pericardium
double-walled sac that surrounds the heart; the outermost layer; resposible for protection, anchors surrounding structures, prevents over-filling
foramen ovale
"oval door" connects the two atria and allows blood entering the right heart to bypass the pulmonary circuit and the collapsed, nonfunctional fetal lungs
hemodynamics
forces the pump (the heart) has to develop to circulate blood through the cardiovascular system; movement of blood
hypertension
high blood pressure
inferior vena cava
returns blood to the right atria from the body areas below the diaphragm
myocardium
middle layer of the heart wall, composed mainly of cardiac muscle and forms bulk of the heart, contractile layer of the heart
mitral valve
bicuspid valve; has 2 valves;left av valve
P wave
first small wave; atrial depolarization
pacemaker
SA node; sets the pace for the heart
pericardium
double walled sac that encloses the heart
pericardial cavity
slitlike cavity between the parietal and visceral layers, which contains a film or serous fluid, creates a friction free environment as the heart beats
Poiseuille's law
a law of physiology stating that blood flow through a vessel is directly proportional to the radius of the vessel to the fourth power.
pulmonary circulation
blood vessels that carry blood to and from the lungs which serves as gas exchange
Pukinje fibers
long strands of barrel shaped cells with few myofibrils, complete pathway through the interventricular septum
QRS complex
ventricular depolarization
semilunar SL valves
aortic and pulmonary; guard the bases of the large arteries issuing from the ventricles and prevent backflow into the associated ventricles
serous pericardium
deep to the fibrous pericardium; a thin, slippery, two-layer serous membrane
sinoatrial SA node
generates impulses 75 times a minute; sets the pace for the heart and contains the pacemaker
superior vena cava
returns blood to the right atrium from body regions superior to the diaphragm
systemic circulation
blood vessels that carry the functional blood supply to and from all body tissues.
systole
contraction
end diastolic volume (EDV)
the amount of blood that collects in a ventricle during diastole
end systole volume (ESV)
the volume of blood remaining in a ventricle after it has contracted
stroke volume
is the volume of the blood pumped out by one ventricle with each beat, about 70mL/beat
T wave
ventricular repolarization
tricuspid valve
the right AV valve has 3 flexible cusps (flaps of endocardium reinforced by connective tissue cones)