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HA Ch. 19 (21)
The Heart
Question | Answer |
---|---|
The heart is a...shaped, ...with two functions | cone...musclar double-pump |
the right side of the heart receives...and pumps blood to... | oxygen-poor blood from body tissues...lungs for oxygenation and dispose of carbon dioxide |
the left side of the heart receives...and pumps... | the oxygenated blood returning from the lungs...oxygen-rich blood throughout the body to supply oxygen and nutrients |
pulmonary circuit includes | blood vessels from the heart that carry blood to and from the lungs |
systemic circuit includes | blood vessels from the heart that transport blood to and from all body tissues |
atria (2) receives | chambers of the hearts and blood from the pulmonary and systemic circuits |
ventricles (2) are the main | pumping chambers that pump blood around circuits |
the pericardium is a | triple-layered sac which is composed of fibrous pericardium and serous pericardium |
fibrous pericardium is the...layer of sac made up of... | outer...dense CT that adheres to the diaphragm inferiorly |
superiorly, the pericardium is fused to | roots of the great vessels that enter and exit the heart |
two layers of serous pericardium include the | parietal layer and the visceral layer |
parietal layer is the...layer which adheres to | outer...inner surface of fibrous pericardium |
visceral layer is the...layer of the serous pericardium and is...with the... | inner...continuous...the parietal layer |
the visceral layer of serous pericardium lies on the | heart and is considered a part of the heart wall |
visceral layer of serous pericardium is also known as | epicardium |
between the parietal and visceral layers, the pericardial cavity contains...which... | serous fluid...decreases friction created between the beating heart and the outer wall of the pericardial sac |
layers of the heart wall include | epicardium, myocardium, endocardium |
epicardium is often | infiltrated with fat, esp in older people |
myocardium forms the..consisting mainly of... | bulk of the heart...cardiac muscle |
the myocardium is the layer that actually | contracts |
cardiac muscle cells (in myocardium) are | elongated, circularly and spirally arranged in networks of cardiac muscles |
endocardium are sheets of | endothelium on a thin layer of CT which lines the heart chambers and makes up the heart valves |
the right and left atria are superiorly divided by | interatrial septum |
the R an L atria are inferiorly divided by | interventricular septum |
the right atrium forms the entire...and is the...via... | entire right border of the human heart...receiving chamber for oxygen-poor blood...three veins |
vessel openings in the right atrium include | superior vena cava, inferior vena cava, and coronary sinus |
superior vena cava is from ...and is superior to the... | upper body regions...diaphragm |
inferior vena cava is from...and is inferior to the... | lower body regions...diaphragm |
coronary sinus is from the | heart wall |
external feature of the right atrium includes the | right auricle |
the right auricle is a...and projects to the | small flap shaped like a dog's ear...left from the superior corner of the atrium |
internal features of the right atrium include | crista terminalis, smooth-walled posterior region, and pectinate muscles |
2 internal regions of the right atrium are seperated by the...which is an important landmark in locating the sites where | crista terminalis...veins enter the right atrium |
anterior region lined by horizontal ridges | pectinate muscles |
fossa ovalis is a | depression in the interatrial septum that marks the spot where an opening existed in the fetal heart, posterior to the end of the crista termanlis |
tricuspid valve | the right atrium opens into the right ventricle through this valve, inferiorly and anteriorly |
right ventricle receives blood from the...and pumps it into the... | right atrium...pulmonary circuit via pulmonary trunk(arteries) |
the right ventricle forms most of the | anterior surface of the heart |
pulmonary valve in the right ventricle; the ...opens into the...through this valve superiorly | right ventricle...pulmonary trunk |
special features of the interior of the R ventricle | trabeculae carneae, papillary muscles, chordae tendinae |
trabeculae carneae | irregular ridges of muscle in the right ventricular wall |
papillary muscles | cone-shaped projections from the walls |
chordae tendinae | strong bands, which project superiorly from the papillary muscles to the flaps (cusps) of the tricuspid valve |
left atrium makes up most of the | heart's posterior surface OR BASE of the heart |
the left atrium receives...returning from the...through... | oxygenated blood...lungs...two right and two left pulmonary veins, via the pulmonary circuit |
the left auricle is the only | visible part of the left atrium anteriorly |
internal feature of the L atrium | pectinate musles |
the walls of the left atrium are mostly... | smooth-surfaced with pectinate muscles lining the auricle only |
the left atrium opens into the...via the... | left ventricle...mitral (bicuspid valve) |
left ventricle is also called the | systemic pump |
the left ventricle dominates the | heart's inferior surface and forms the apex of the heart |
the left ventricle pumps | oxygenated blood into the systemic circuit |
special features of the interior of the left ventricle include | trabeculae carneae, papillary muscles, chordae tendinae, cusps of mitral valve |
supeirorly, the left ventricle opens into the | stem artery (aorta) of the systemic circulatioin via aortic (semilunar) valve |
pathway of blood through the heart; oxygen poor blood enters the | heart's right atrium |
oxygen poor blood comes into the right atrium from | upper body regions superior to the diaphragm via the superior vena cava |
oxygen poor blood comes into the right atrium also from the | lower body regions inferior to the diaphragm via the inferior vena cava |
oxygen poor blood comes into the right atrium from the heart | wall via the carotid sinus |
the r atrium...and, with the aid of..., the oxygen poor blood is propelled from the...through the...to the... | gravity...right atrium...tricuspid valve...right ventricle |
the r ventricle contracts and propels blood through the | pulmonary semilunar valve through the pulmonary trunk (arteries) |
the oxygen-poor blood flows to the | lungs via the pulmonary circuit to become oxygenated and to dispel carbon dioxide |
the oxygen-rich blood flows | back to the heart and enters the left atrium via the pulmonary veins |
the l atrium contracts and propels...blood through the | oxygenated blood..mitral valve to the left ventricle |
the left ventricle contracts and propels blood through the... | aortic semilunar valve out of the heart through the aorta and its branches |
this oxygenated blood is pumped throughout the body via the | systemic circuit to deliver oxygen and nutrients to body tissues |
after the exchange, the blood becomes...and returns to the... | oxygen poor again...heart's right atrium to continue the cycle through the pulmonary and systemic circuits |
the heart valves enforce the...through the heart in the following order: | one way flow of blood...atria, ventricles, great arteries (pulmonary trunk and aorta) |
each heart valve consists of | two or three cusps, flaps of endocardium, reinforced by cores of dense CT |
atrioventricular (AV) valves are located at | junctions of the atria & their respective ventricles |
right atrioventircular valve | tricuspid valve - 3cusps |
left atrioventricular valve | bicuspid valve/mitral valve - 2 cusps |
semilunar valves are located at the | junction of the ventricles and the great arteries |
pulmonary semilunar valve | right ventricle to pulmonary trunks (3 cusps) |
aortic semilunar valve | left ventricle to aorta (3 cusps) |
when a valve is open it allows | blood flow |
when a valve is closed it prevents | backflow of blood |
AV valves prevent the | backflow of blood into the atria during ventricular contraction |
the chordae tendinae and papillary muslces that attach to the AV valves serve as | guy wires by anchoring the cusps in their closed position |
AV valves prevent backflow into the | atria during ventricular contraction |
semilunar valves prevent | backflow from the great arteries into the ventricles |
closing of the valves causes | vibrationsin the adjacent blood and heart walls, resulting in "lub-dub" sounds |
lub = | closing of AV valves at the start of ventricular systole |
dub = | closing of semilunar valves at the end of ventricular systole |
the fibrous skeleton of the heart is made of | electrically inert, dense CT that lies in the plane between the atria and ventricles |
the fibrous skeleton of the heart surrounds all | four heart valves like handcuffs |
the fibrous skeleton anchors the | valve cusps |
the fibrous skeleton prevents | overdilation of the valve openings as blood flows through |
the fibrous skeleton is the point of | insertion for cardiac muscle bundles in the atria and ventricles |
the fibrous skeleton blocks the | direct spread of eletrical impulses from the atria to the ventricles |
the cardiac cycle consists of | periods of systole and diastole |
the sequence of contraction in vivo = | both the atria always contract together followed by the ventricles simultaneously contracting |
heart beat | single sequence of atrial contraction followed by ventricular contraction |
systole (atrial or ventricular) | contraction of a heart chamber |
diastole (atrial or ventricular) | time during which the heart chamber is relaxing and filling with blood |
both atria and ventricles experience | systole and diastole |
the walls of the atria are much...than those of ventricles because the atria need to... | thinner...exert little effort with the aid of gravity to propel blood inferiorly to the ventricles |
the intrinsic means by which the heart muscle | generates and conducts electrical impulses |
the conducting system is a series of | specialized cardiac muscle cells that carry impulses throughout the heart musculature, signaling the heart chambers to contract in the proper sequence |
conducting system component; sinoatrial node is a ...shaped mass of...that lies in the... | crescent...muscle cells...wall of the right atrium just inferior to the entrance of the superior vena cava |
the impulse that signals each heartbeat begins at the | sinoatrial node |
the sinoatrial node sets the | basic heart rate by generating 70-80 pulses/min and is the heart's pacemaker |
conducting system components; internodal fibers go from the..to the... | sinoatrial node...AV node |
atrioventriculare node (AV) cells are...but typical... | small...cardiac muslce cells |
a brief delay of...occurs in the AV node to ensure that the ventricles... | contraction-signaling impulses...fill completely before contraction |
conducting system components; AV bundle cells are | small but typical cardica muscle cells |
conducting system components; R and L bundle branches | crura |
conducting system components; purkinje fibers are also called... which are special... | conduction myofibers...large-diameter, barrel-shaped muscle cells called purkinje myocytes, containing relatively few myofilaments |
extrinsic neuralcontrols can alter | the heart's inherent rate set by the SA node |
visceral sensory fibers | nerves supplying the heart |
parasympathetic fibers decrease the | heart rate; arise as branches of the vagus nerve in the neck and thorax |
sympathetic fibers increase the | rate and force of heart contractions. from the cervical and upper thoracic ganglia |
all nerves serving the heart pass through the | cardiac plexus on the trachea before entering the heart |
the autonomic nervous system fibers project to the | cardiac musculature, but mostly project to the SA and AV nodes and the coronary arteries |