Chapter 20: The Heart Flashcards
the blood vessels in the cardiovascular system are subdivided into the…
pulmonary and systemic circuits
blood is carried away from the heart in…
arteries
the left atrium recieves blood from the pulmonary circuit and empties it into the…
left venticle
the “double pump” function of the heart includes the right side, which serve as the ________ circuit pump, while the left side serves as the _______ pump.
pulmonary; systemic
the major difference between the left and right ventricles relative to their role in heart function is…
the LV pumps blood through the high-resistance systemic circulation
the great cardiac vein drains blood from the heart muscle to the…
right atrium
the visceral pericardium, or epicardium, covers the…
outer surface of the heart
the valves of the heart are covered by the squamous epithelium, the…
endocardium
the three distinct layers of the heart wall include the…
epicardium, myocardium, and endocardium
atrioventricular valves prevent backflow of blood into the_______; semilunar valves prevent backflow into the________.
atria; ventricles
blood flows from the left atrium into the left ventricle through the __________ valve.
- bicuspid
- L atrioventricular
- mitral
when deoxygenated blood leaves the right ventricle through a semilunar valve, it is forced into the…
pulmonary arteries
blood from systemic circulation is returned to the right atrium by the….
superior and inferior vena cava
oxygenated blood from the systemic arteries flows into…
peripheral tissue capillaries
the lung capillaries recieve deoxygenated blood from the….
pulmonary arteries
one of the important differences between skeletal muscles tissue and cardiac muscle tissue is that cardiac muscle tissue is…
striated involuntary muscle
cardiac muscle tissue…
does not require nerve activity to stimulate a contraction
the primary difference that characterize cardiac muscle cells when comparing them to skeletal muscle fibers is…
- small size
- a single, centrally located nucleus
- the presence of intercalated discs
blood from coronary circulation is returned to the right atrium of the heart via…
the coronary sinus
the right coronary artery supplies blood to…
- the right atrium
- portions of the conducting system of the heart
- portions of the right and left ventricles
the correct sequential path of a normal action potential in the heart is:
SA node->AV node->AV bundle->bundle braches->Purkinje fibers
if the papillary muscles fail to contract, the…
AV valves will not close properly
the sinoartrial nodes acts as the pacemaker of the heart because these cells are…
the ones that depolarize and reach threshold first
after the SA node is depolarized and the impulse spread through the atria, there is a slight delay before the impulse spreads to the ventricles. The importance of this delay is that it allows…
the atria to finish contracting
if each heart muscle cell contracted at its own individual rate, the condition would resemble…
fibrillation
the P wave of a normal electrocardiogram indicates…
atrial depolarization
the QRS complex of the ECG appears as the…
ventricles depolarize
ECGs are useful in detecting and diagnosing abnormal patterns of cardiac activity called…
cardiac arrhythmias
an excessively large QRS complex often indicates that the…
heart has become enlarged
the events between the start of one heartbeat and the start of the next are called the…
cardiac cycle
the “lubb-dupp” sounds of the heart have practical clinical value because they provide information concerning the…
action and effieciency of the AV and semilunar valves
when the chamber of the heart fills with blood and prepares for the start of the next beat, the chamber is in…
diastole
at the start of atrial systole, the ventricles are filled to around _________ of capacity.
70 percent
the amount of blood ejected by the left ventricle per minute is the…
cardiac output
the amount of blood pumped out of each ventricle during a single beat is the…
stroke volume
under normal circumstances, the factors responsible for making delicute adjustments to the heart rate as circulatory demands change are…
autonomic activity and circulatory hormones
the cardiac centers in the medulla oblongata monitor baroreceptors and chemorecpetors innervated by the…
glossopharyngeal N IX and vagus N X
the atrail reflex involves adjustments in heart rate stimulated by an increase in…
venous return
the difference between the end-diastolic and the end-systolic volume is the…
stroke volume
the Frank-Starling principle describes the observed relationship that…
increasing the EDV results in an increase in the stroke volume
parasympathetic stimulation from the vagus nerve results in…
a decrease in heart rate
cutting the vagus nerve…
increases the heart rate
if the heart rate is 78 bpm and the stroke volume is 80 mL per beat, the cardiac output is…
6240 mL/min
assuming anatomic position, the best way to describe the specific location of the heart in the body is…
within the mediastinum of the thorax
the function of the chordae tendineae is to…
anchor the AV valve flaps and prevent backflow of blood into the atria
what does not show up in an electrocardiogram?
murmurs
decreased parasympathetic stimulation to the heart results in…
accelerating heart rate
serious arrhythmias that reduce the pumping effiencey of the hear may indicate…
- damage to the myocardium
- injury to the SA and AV nodes
- abnormalities in the ionic composition of the extracellular fluids
what does not increase afterload?
vasodilation of peripheral vessels
ventricular diastole indicates that…
the ventricle are “resting”
what does not control the movement of blood through the heart?
size of the atria and ventricles
the ANS can make very delicate adjustments in cardiovascular function to meet demands of other systems through…
dual innervation and adjustments in autonomic tone
normally, the only electrical connection between the atria and the ventricles is the…
AV bundle
if the SA node or internodal pathways are damaged, the…
AV node assumes command
tetanic contractions cannot occur in a normal cardiac muscle cell, regardless of the frequency or intensity of stimulation, because…
summation is not possible
