A&P:AN INTEGRATIVE APP.LAB MAN.+CONNECT
2nd Edition
ISBN: 9781260485356
Author: McKinley
Publisher: MCG CUSTOM
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Textbook Question
Chapter 19, Problem 7DYKB
Why is it necessary to stimulate papillary muscles in the ventricle slightly earlier than the rest of the ventricular wall myocardium?
- a. to assure rapid conduction speed of the action potential
- b. to pull on AV valve cusps to prevent backflow
- c. to assure blood will surge toward the semilunar valves
- d. to assure coordinated contraction of the ventricular myocardium
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Why is it necessary to stimulate papillary muscles in the ventricle slightly earlier than the rest of the ventricular wall myocardium?
a. to assure rapid conduction speed of the action potential
b. to pull on AV valve cusps to prevent backflow
c. to assure blood will surge toward the semilunar valves
d. to assure coordinated contraction of the ventricular myocardium
SA node is the main pacemaker of the heart. Why is the normal heart rate lower than the intrinsic firing rate of the SA node?
A. sympathetic inputs from the hypothalamus are slowing it down
B. parasympathetic inputs from medulla oblongata are slowing it down
C. there is inertia in heart muscle as it takes time for impulse to spread through all the cells
D. centrifugal inputs from the AV node are slowing it down
which of the following mechanisms contributes most to the deterioration of myocardial perfusion in patients with a progressively dilating left ventricle and a cycle of gradual decompensation.
A. decreasing left ventricular radius B. decreasing peripheral vascular resistance C. decreasing vestibular pressure D. increasing left ventricular wall tension E. increasing left ventricular wall thickness
Chapter 19 Solutions
A&P:AN INTEGRATIVE APP.LAB MAN.+CONNECT
Ch. 19.1 - What are the potential consequences of a failing...Ch. 19.1 - Prob. 2WDYLCh. 19.1 - What path does blood follow through the heart?...Ch. 19.1 - Which of the great vessels is both an artery and...Ch. 19.2 - Prob. 5WDYLCh. 19.2 - Describe the three layers that cover the heart....Ch. 19.3 - Prob. 7WDYLCh. 19.3 - What are the layers of the heart (in order) that a...Ch. 19.3 - What is the structure that separates the two...Ch. 19.3 - What are the functions of the tendinous cords and...
Ch. 19.3 - Which features of cardiac muscle support aerobic...Ch. 19.3 - Which function of the fibrous skeleton allows the...Ch. 19.4 - What areas of the heart are deprived of blood when...Ch. 19.4 - Prob. 14WDYLCh. 19.5 - Prob. 15WDYLCh. 19.5 - Which autonomic division is associated with the...Ch. 19.6 - Prob. 17WDYLCh. 19.6 - What is autorhythmicity? Describe how nodal cells...Ch. 19.6 - What is the path of an action potential through...Ch. 19.6 - What anatomic features slow the conduction rate of...Ch. 19.7 - In which direction does Ca2+ move in response to...Ch. 19.7 - What three electrical events occur at the...Ch. 19.7 - What is the significance of the extended...Ch. 19.7 - What events in the heart are indicated by each of...Ch. 19.8 - Pressure changes that occur during the cardiac...Ch. 19.8 - What is occurring during ventricular ejection?Ch. 19.8 - Prob. 27WDYLCh. 19.8 - Define end-diastolic volume, end-systolic volume,...Ch. 19.9 - What are the two factors that determine cardiac...Ch. 19.9 - What is the cardiac output at rest and during...Ch. 19.9 - Prob. 31WDYLCh. 19.9 - Describe the atrial reflex, which involves...Ch. 19.9 - Prob. 33WDYLCh. 19.9 - Prob. 34WDYLCh. 19.10 - What would be the path of blood flow through the...Ch. 19 - Which of the following is the correct circulatory...Ch. 19 - The pericardial cavity is located between the a....Ch. 19 - How is blood prevented from backflowing from the...Ch. 19 - ____ 4. Venous blood draining from the heart wall...Ch. 19 - _____ 5. Calcium channels in the nodal cells...Ch. 19 - ____6. Action potentials are spread rapidly...Ch. 19 - Why is it necessary to stimulate papillary muscles...Ch. 19 - ____ 8. Preload is a measure of a. stretch of...Ch. 19 - ____ 9. All of the following occur when the...Ch. 19 - ____10. What occurs during the atrial reflex? a....Ch. 19 - Prob. 11DYKBCh. 19 - Compare the structure, location, and function of...Ch. 19 - Prob. 13DYKBCh. 19 - Explain why the walls of the atria are thinner...Ch. 19 - Describe the structure and function of...Ch. 19 - Explain the general location and function of...Ch. 19 - Describe the functional differences in the effects...Ch. 19 - Prob. 18DYKBCh. 19 - List the five events of the cardiac cycle, and...Ch. 19 - Define cardiac output, and explain how it is...Ch. 19 - A young man was doing some vigorous exercise when...Ch. 19 - A young man was doing some vigorous exercise when...Ch. 19 - Prob. 3CALCh. 19 - Prob. 4CALCh. 19 - During surgery, the right vagus nerve was...Ch. 19 - Prob. 1CSLCh. 19 - Prob. 2CSLCh. 19 - Your grandfather was told that his SA node...
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