Chapter Quiz 4: Cardiovascular
Calculate the end diastolic volume of a heart beating at 74 beats per min, with a cardiac output of 4.7 L/min and ejection fraction of 47 %. Report your value to the nearest ml.
135
Calculate the cardiac output of a heart beating at 111 beats/min with an end diastolic volume of 141 ml and a end systolic volume of 65 ml. Report your answer to the nearest tenth of a L/min.
8.4
In the condition known as "complete heart block," what happens?
Electrical signals from the SA node never reach the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles.
The steep repolarization phase of the action potentials of myocardial contractile cells is due to which ion(s)?
K+
If channels are permeable to
Na+ and K+
The repolarization phase (after of the plateau phase) in a cardiac action potential is due to the __________ of Ca2+channels and __________ of K+ channels.
closing, opening
When baroreceptors sense a loss of blood pressure, they __________ their firing rate.
decrease
Each of the following changes will result in increased blood flow to a tissue except one. Identify the exception.
decreased vessel diameter
The pulmonary artery carries _______________ blood _______________ the heart.
deoxygenated, away from
A P-wave represents the
depolarization of the atria
All blood vessels are lined with a thin layer of
endothelium
Red blood cell production is regulated by the cytokine
erythropoietin.
Due to the differences in opposing forces, there is net __________ occurring at the arteriolar end of most capillaries, coupled with net __________ at the venous end.
filtration, absorption
The unstable resting potential of cardiac autorhythmic cells is largely due to the
influence of If channels
In Lead II of an ECG, the positive electrode can be placed on the ________ and the negative electrode can be placed on the _________.
left foot, right arm
Compared to skeletal muscle, the action potential of cardiac contractile cells is
longer
The driving force of blood flow is a(n) __________ gradient.
pressure
The importance of the plateau phase of the action potential of myocardial cells is in
preventing summation and tetanus
The values obtained when taking a blood pressure, such as 120/80, (pick the most complete answer)
reflect the pressure in the major arteries during ventricular systole and diastole.
In cardiac muscle,
some of the calcium ion required for contraction comes from outside of the cell.
Myogenic autoregulation means that (pick the most complete answer)
stretched smooth muscle in a blood vessel constricts reflexively.
The first heart sound is heard when
the AV valves close.
The common pathway of coagulation begins with
the activating of a clotting factor that converts prothrombin to thrombin.
Parasympathetic stimulation can slow down heart rate via the action of acetylcholine released by the
vagus nerve
The first steps in hemostasis involve ____________ and ______________.
vasoconstriction, platelet plug formation
Catecholamines such as norepinephrine increase the pacemaker potential of cardiac autorhythmic cells by binding to ______________ receptors.
β1 adrenergic
The most abundant proteins in blood plasma are
albumins
The 0.12 msec delay in conduction of an Action Potential through the AV node primarily
allows the atria to finish emptying before the ventricles start to contract
