chapter 20 - the heart Flashcards
how many times does blood pass through the heart?
two times
what side of the body has deoxygenated blood?
the right side
what type of circulation occurs on the right side of the body?
pulmonary circulation
what type of circulation occurs on the left side of the body?
systemic circulation
which type of circulation goes to the lungs (and back)?
pulmonary circulation
what type of circulation goes out to the body?
systemic circulation
what does the apex of the heart rest on?
the diaphragm
what is the thin, transparent outer later of the heart wall?
epicardium
what is another name for the epicardium?
visceral layer of the serous pericardium
what is the thick, middle layer of the heart wall?
myocardium
what type of muscle is the myocardium composed of?
cardiac muscle
which part of the heart wall is in direct contact with blood?
endocardium
what helps minimize friction as the blood passes through the heart?
the endocardium
what is continuous with the inside of blood vessels?
the endocardium
what is the membrane that surrounds and protects the heart?
the pericardium
what part of the pericardium is composed of dense, irregular connective tissue?
fibrous pericardium
what part of the pericardium is more thin and delicate?
the serous pericardium
what are the two layers of the serous pericardium?
the parietal layer and the visceral layer
what part of the serous pericardium is fused to fibrous pericardium?
parietal layer
what part of the serous pericardium adheres to the heart wall?
visceral layer
what is the space between the layers of serous pericardium?
the pericardial cavity
what reduces friction between two layers of serous pericardium as the heart moves?
the pericardial fluid
what is an acute inflammation of the pericardium?
pericarditis
what mimics the symptoms of a heart attack?
pericarditis
what is a chronic condition of the heart that decreases cardiac output?
cardiac tamponade
what is the superior part of the heart?
the atria
what receives blood from veins?
the atria
what is a blood vessel that returns blood to the heart?
a vein
what pumps blood out of the heart into arteries?
ventricles
what takes blood away from the heart?
arteries
what side of the heart receives blood from the lungs and pumps it to the rest of the body?
the left side, systemic circulation
what side of the heart receives blood from the body and returns it to the lungs?
the right side, pulmonary circulation
what prevents back flow of blood by opening and closing in response to pressure changes?
valves
what are “one way doors”?
valves
what are the four valves of the heart?
two atrioventricular valves and two semilunar valves
what type of valve is the tricuspid and bicuspid valve?
atrioventricular valves
what is another name for the bicuspid valve?
mitral valve
what is the name of the valve between the right atrium and the ventricle?
the tricuspid valve
what is the name of the valve between the left atrium and ventricle?
the bicuspid (mitral) valve
what is found between the ventricles and arteries leading away from the heart?
semilunar valves
which valve opens from the right ventricle into the pulmonary trunk to the lungs?
the pulmonary valve
which valve opens from the left ventricle into the aorta to the body?
the aortic valve
where does the myocardium receive its oxygen and nutrients from?
from blood glowing through the coronary circulation
what branches from the ascending aorta and supplies blood to the myocardium?
the left and right coronary arteries
what collects the into the coronary sinus on the back part of the heart?
coronary veins
where do coronary veins empty?
into the right atrium
what are 1% of the muscle cells of the heart called?
autorhythmic fibers
what type of fibers are self excitable?
autorhythmic fibers
what is responsible for the heart beating even after removal from the body?
autorhythmic fibers
what acts as a pacemaker and forms a cardiac conduction system?
autorhythmic fibers
what sets a rhythm of contraction with the heart?
pacemaker
what is a system of specialized muscle cells that ensures that the heart contracts in a systematic, coordinated way?
cardiac conduction system
what do cardiac muscle and skeletal muscle have in common?
they are both striated
where do cardiac muscle cells connect to and communicate through neighboring cells?
gap junctions
where are gap junctions?
intercalated discs
what is the SA node?
the sinonartiral node
what is the AV node?
the atrioventricular node
what is the bundle of His?
the atrioventricular bundle
what is the recording of electrical changes resulting from depolarization and repolarization of the myocardium?
ECG (electrocardiogram)
what does an ECG detect?
P wave, PQ-interval, QRS wave/complex, T wave, and Q-T interval
what is atrial depolarization in an ECG?
P wave
what is the ventricular depolarization in an ECG?
QRS wave
what is the time from beginning of ventricular depolarization to the end of ventricular repolarization?
Q-T interval
what is the relaxation phase of the heart?
diastole
what is the contraction phase of the heart?
systole
when are ventricles relaxed?
atrial systole
when are the atria relaxed?
ventricle systole
what is it called when you listen to the sounds of the heart?
auscultation
what creates the “lubb dupp” sound of the heart?
closure of the valve (opening is silent)
what is the beginning of ventricular systole?
S1, the closure of AV valves
what is the closure of semilunar valves?
S2, begninning of ventricular diastole
what are all events associated with one heartbeat called?
the cardiac cycle
what is a contraction of both the atria and ventricles?
systole
what is the relaxation of both the atria and ventricles?
diastole
what is the volume of blood ejected from the left ventricle each minute called?
cardiac output (CO)
what is the volume of blood ejected from he left ventricle every beat called?
stroke volume (SV)
what are the three factors that regulate stroke volume?
preload, contractility, and after load
what is the degree of stretch on the heart before it contracts?
preload
what is the forcefulness of ventricular (muscle) contraction?
contractility
what is the pressure that must be exceeded before ejection of blood from ventricles can occur?
afterload
what part of the brain helps regulate heart rate?
medulla oblongata