Download Chapter 12 A and B questions

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Chapter 12 Section A Overall Design of the Cardiovascular System
Revised 26 October 2008
Define hematocrit. What are the units of Hct and what is a normal value for males?
females?
What is the approximate blood volume for an average sized-person?
What is the systemic circuit? the pulmonary circuit?
Beginning with the left ventricle, trace the route of blood through each of the vessels,
valves, and chambers in sequence ending with the return of blood to the left ventricle.
Which vessels constitute the microcirculation?
Which vessels are the site of exchange between the blood and tissues?
What is the mathematical relationship between flow, pressure gradient, and resistance?
Be able to use this equation to determine how flow is affected when pressure gradient
change or resistance changes.
Write Poiseuille's equation, define the variables, note which variables are under
physiological control and which contribute to resistance. Which of the variables has the
greatest impact on blood flow?
How is blood flow affected if the radius of a vessel is doubled? halved?
Chapter 12 Section B The Heart
Name the atrioventricular valves and the semilunar valves. Which are attached to
papillary muscles? What are the functions of papillary muscles?
Describe the shape of cardiac myofibers and the structures by which they are attached to
each other.
Name the components of the electrical conducting system of the heart.
By which types of nerves is the heart innervated? What types of neurotransmitter
receptors are in the heart?
Where are coronary vessels found and what is their function?
Where does an action potential first appear in the heart and by which pathways does the
action potential spread throughout the heart?
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How does the AV node affect the rate of AP conduction and why is this important?
What is the role of Purkinje fibers?
How does an action potential in a cardiac myofiber differ from that of a skeletal muscle?
What is its shape, approximate duration, and which ions are responsible for the rising,
plateau, and falling phases?
Which ions moving in which directions account for the plateau phase of the action
potential in cardiac myofibers?
How can pacemaker cells be identified electrically?
What would the heart rate be if all neural and hormonal inputs were eliminated?
What is an ectopic pacemaker? Which cells usually take over pacemaker functions if the
AV node is defective?
What events in the heart generate the P, QRS, and T waves of the electrocardiogram?
What types of heart block are depicted in Figure 12-16?
(From lab) What are the distinguishing features of 1st, 2nd, and 3rd degree heart block?
What is the importance of Ca++ induced- Ca++ release? Could this be considered an
example of positive feedback?
How is cytosolic Ca++ concentration related to the force of contraction of cardiac
myofibers?
Why can't the heart muscle experience summation or tetanic contraction? Why would
tetanic contractions of the heart be lethal?
What is systole? diastole?
What is stroke volume? What is the normal value (give units.)
During a cardiac cycle, there are two brief periods when the volume of the ventricle does
not change. What is this condition called and what are the states of the valves during
these intervals?
What percentage of ventricular filling occurs prior to atrial contraction?
Figure 12-19 is one of the more important figures in all of physiology. Study it carefully
for the timing of events and the values on the y-axis. Be able to draw and label such a
figure. Pay attention to the values on the y-axis.
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What causes heart valves to open and close?
What is end-diastolic volume? What is the normal value (give units.)
How much blood remains in the ventricle at the end of a typical systole?
At heart rates in excess of 200 beats per minute, how is stroke volume affected?
What is atrial fibrillation and why isn't it deadly?
What is the main difference in the cardiac cycle when comparing the left and right
ventricles?
Why is the pressure in the pulmonary circuit so much less than the systemic circuit?
How does the stroke volume of the two ventricles compare? Which has a greater stroke
volume?
What causes the first heart sound? the second heart sound? a heart murmur?
What is the difference between valvular stenosis and insufficiency?
What is the formula for cardiac output? What is the normal value (give the units.)
Isolated pacemaker cells produce about 100 action potentials per minute. Why isn't the
heart rate this fast in a person?
How does sympathetic activity affect heart rate? What neurotransmitter is involved?
Which hormone?
How does parasympathetic activity affect heart rate? What neurotransmitter is involved?
Which nerve and which type of receptor are responsible?
How is the membrane potential of pacemaker cell altered by sympathetic and
parasympathetic inputs?
Distinguish between preload and afterload.
What are the two dominant factors that determine stroke volume?
Put into words the Frank-Starling law of the heart.
What is venous return?
How does sympathetic activity affect contractility, ejection fraction, and the duration of
contraction? How is Ca++ involved in this affect?
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How does parasympathetic activity affect contractility and ejection fraction?
What non-invasive clinical technique can be used to measure ejection fraction?
What invasive clinical technique can be used to examine coronary vessels?
What is angina pectoris?
Study carefully the Figure 12-28 on p. 382. This is a concise summary.