blood Flashcards
A foramen ovale ________.
-is a connection between the pulmonary trunk and the aorta in the fetus
-connects the two atria in the fetal heart
-is a shallow depression in the interventricular septum
-is a condition in which the heart valves do not completely close
connects the two atria in the fetal heart
Blood within the pulmonary veins returns to the ________.
left atrium
left ventricle
right atrium
right ventricle
left atrium
Commotio cordis is heart failure due to a ________.
-severe electrical shock to the body
-loss of blood from an artery
-mild electrical shock to the heart itself
-relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing
relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing
Compared to skeletal muscle, cardiac muscle ________.
-has gap junctions that allow it to act as a functional syncytium
-has more nuclei per cell
-cells are larger than skeletal muscle cells
-lack striations
has gap junctions that allow it to act as a functional syncytium
Damage to the ________ is referred to as heart block.
AV bundle
AV valves
AV node
SA node
AV node
During contraction of heart muscle cells ________.
-calcium is prevented from entering cardiac fibers that have been stimulated
-the action potential is initiated by voltage-gated slow calcium channels
-some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
-the action potential is prevented from spreading from cell to cell by gap junctions
some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
During the period of ventricular filling ________.
-it is represented by the P wave on the ECG
-the atria remain in diastole
-blood flows mostly passively through the atria and the open AV valves into the ventricles
-pressure in the heart is at its peak
blood flows mostly passively through the atria and the open AV valves into the ventricles
Hemorrhage with a large loss of blood causes ________.
-no change in blood pressure but a slower heart rate
-a rise in blood pressure due to change in cardiac output
-no change in blood pressure but a change in respiration
-a lowering of blood pressure due to change in cardiac output
a lowering of blood pressure due to change in cardiac output
If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.
-an inadequate supply of lactic acid
-a decrease in the number of available mitochondria for energy production
-a lack of nutrients to feed into metabolic pathways
-decreased delivery of oxygen
decreased delivery of oxygen
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________.
-it would be less than 1—2 m
-contractions would last as long as the refractory period
-tetanic contractions might occur, which would stop the heart’s pumping action
-it would be much longer before cardiac cells could respond to a second stimulation
tetanic contractions might occur, which would stop the heart’s pumping action
If the vagal nerves to the heart were cut, the result would be that ________.
-the heart would stop, since the vagal nerves trigger the heart to contract
-parasympathetic stimulation would increase, causing a decrease in heart rate
-the AV node would become the pacemaker of the heart
-the heart rate would increase by about 25 beats per minute
the heart rate would increase by about 25 beats per minute
If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.
-tetanic contraction would occur due to the short absolute refractory period of cardiac muscle
-heart rate would decrease, but blood pressure would rise due to the excess sodium present
-potassium channels compensate and no change in heart rate would occur
-threshold is reached more quickly and heart rate would increase
threshold is reached more quickly and heart rate would increase
Isovolumetric contraction ________.
-refers to the short period during ventricular systole when the ventricles are completely closed chambers
-occurs immediately after the aortic and pulmonary valves close
-occurs only in people with heart valve defects
-occurs while the AV valves are open
refers to the short period during ventricular systole when the ventricles are completely closed chambers
Norepinephrine acts on the heart by ________.
-decreasing heart contractility
-blocking the action of calcium
-causing threshold to be reached more quickly
-causing a decrease in stroke volume
causing threshold to be reached more quickly
Normal heart sounds are caused by which of the following events?
-closure of the heart valves
-friction of blood against the chamber walls
-opening and closing of the heart valves
-excitation of the SA node
closure of the heart valves
Select the correct statement about cardiac output.
-A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.
-If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased.
-Stroke volume increases if end diastolic volume decreases.
-Decreased venous return will result in increased end diastolic volume.
A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.
Select the correct statement about the function of myocardial cells.
-Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate.
-The refractory period in skeletal muscle is much longer than that in cardiac muscle.
-The entire heart contracts as a unit or it does not contract at all.
-The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.
The entire heart contracts as a unit or it does not contract at all.
Select the correct statement about the heart valves.
-The mitral valve separates the right atrium from the right ventricle.
-The tricuspid valve divides the left atrium from the left ventricle.
-The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
-Aortic and pulmonary valves control the flow of blood into the heart.
The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
Select the correct statement about the structure of the heart wall.
-The myocardium is the layer of the heart that actually contracts.
-The fibrous skeleton forms the bulk of the heart.
-Connective tissue in the heart wall aids in the conduction of the action potential.
-The heart chambers are lined by the endomysium
The myocardium is the layer of the heart that actually contracts.
The P wave of a normal electrocardiogram indicates ________.
ventricular depolarization
ventricular repolarization
atrial depolarization
atrial repolarization
atrial depolarization
The condition where fluid compresses the heart and limits its ability to contract is called ________.
angina pectoris
cardiac tamponade
pericarditis
myocardial infarction
cardiac tamponade
The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________.
-sends blood through a smaller valve
-pumps a greater volume of blood
-pumps blood against a greater resistance
-expands the thoracic cage
pumps blood against a greater resistance
The left ventricular wall of the heart is thicker than the right wall in order to ________.
-accommodate a greater volume of blood
-pump blood with greater pressure
-pump blood through a smaller valve
-expand the thoracic cage during diastole
pump blood with greater pressure
The second heart sound is heard during which phase of the cardiac cycle?
ventricular ejection
ventricular filling
isovolumetric relaxation
isovolumetric contraction
isovolumetric relaxation
The source of blood carried to capillaries in the myocardium would be the ________.
coronary veins
coronary arteries
fossa ovalis
coronary sinus
coronary arteries
The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________.
pericarditis
ischemia
angina pectoris
myocardial infarct
angina pectoris
The tricuspid valve is closed ________.
-when the ventricle is in systole
-while the ventricle is in diastole
-by the movement of blood from atrium to ventricle
-while the atrium is contracting
when the ventricle is in systole
To auscultate the aortic semilunar valve, you would place your stethoscope in the ________.
-fifth right intercostal space
-fifth intercostal space inferior to the left nipple
-second intercostal space to the right of the sternum
-second intercostal space to the left of the sternum
second intercostal space to the right of the sternum
When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________.
-locating the apex
-noticing the thickness of the ventricle walls
-finding the papillary muscles
-tracing out where the auricles connect
noticing the thickness of the ventricle walls
Which of the events below does not occur when the semilunar valves are open?
-Ventricles are in diastole.
-Ventricles are in systole.
-AV valves are closed.
-Blood enters pulmonary arteries and the aorta.
Ventricles are in diastole.
Which of the following factors does not influence heart rate?
body temperature
skin color
gender
age
skin color
Which of the following is not an age-related change affecting the heart?
-decline in cardiac reserve
-thinning of the valve flaps
-atherosclerosis
-fibrosis of cardiac muscle
thinning of the valve flaps
Which of the following is not part of the conduction system of the heart?
SA node
AV valve
AV node
bundle of His
AV valve
Which of these vessels receives blood during ventricular systole?
-both the aorta and pulmonary trunk
-pulmonary veins only
-pulmonary arteries only
-aorta only
both the aorta and pulmonary trunk
Which vessel(s) of the heart receive(s) blood during right ventricular systole?
pulmonary veins
pulmonary trunk
venae cavae
aorta
pulmonary trunk
