Chapter 12 Flashcards
(31 cards)
Which of the following does NOT influence stroke volume?
A) Changes in end-diastolic volume (preload)
B) Changes in sympathetic input
C) Changes in venous pressure
D)Changes in arterial pressure (afterload)
C) Changes in venous pressure
Baroreceptors are located... A) in the aorta and subclavian arteries. B) in the aorta and carotid arteries. C) aorta and carotid veins. D) aorta and subclavian veins. E) aorta and common iliac arteries.
B) in the aorta and carotid arteries.
Action potentials are conducted from the baroreceptors to the brain via…
A) the vagus nerve.
B) the vagus and glossopharyngeal nerves.
C) the vagus and phrenic nerves.
D) the phrenic and glossopharyngeal nerves.
E) the phrenic nerve.
B) the vagus and glossopharyngeal nerves.
The action potential from the brain to the heart travels along…
A) the vagus nerve.
B) the vagus and glossopharyngeal nerves.
C) the vagus and phrenic nerves.
D) the phrenic and glossopharyngeal nerves.
E) the phrenic nerve.
A) the vagus nerve.
T or F: Heart rate and stroke volume decrease under decreased parasympathetic stimulation.
False
T or F: Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal.
False
Chemoreceptors in the carotid and aortic bodies detect all of the following except... A) oxygen levels B) blood pressure C) pH D) carbon dioxide E) both A and D
B) blood pressure
Chemoreceptors are also located in the... A) medulla oblongata. B) pons. C) hypothalamus. D) thalamus. E) spinal cord.
A) medulla oblongata.
Which of the following will not increase the heart rate? A) decreased blood oxygen B) increased blood carbon dioxide C) increased blood pressure D) decreased blood pH
C) increased blood pressure
T or F: Increased sympathetic stimulation causes increased heart rate and stroke volume.
True
T or F: Chemoreceptors in the hypothalamus monitor blood carbon dioxide and pH.
False
Which vessel type is not correctly matched with one of its functions?
A) arteries - conduct blood away from the heart
B) arterioles - return blood from the tissues to the atria
C) capillaries - site of exchange of substances between the blood and tissue fluid
D) veins - serves as a blood reservoir
B) arterioles - return blood from the tissues to the atria
The endothelium secretes chemicals that
A) increase cardiac output
B) decrease heart rate
C) inhibit platelet aggregation and control blood vessel diameter
D) nourish the cells in the outer half of the blood vessel wall
C) inhibit platelet aggregation and control blood vessel diameter
When someone is not exercising, most of his total blood volume is in the A) heart B) arteries C) capillaries D) veins
D) veins
*The veins have large lumens and therefore slower flow rates. Blood accumulates in the venous vessels, and the veins serve as a “reservoir” of extra blood that can be transferred to the arteries during exercise.
Vasoconstriction
A) occurs when smooth muscle in the vessel wall relaxes
B) can be caused by signals from the sympathetic nervous system
C) increases blood flow in the constricted vessel
D) decreases blood pressure in the constricted vessel.
B) can be caused by signals from the sympathetic nervous system
Vasoconstriction is due to smooth muscle contraction. It increases pressure and reduces flow through vessels.
The maximum pressure developed in a systemic artery A) is called the systolic pressure B) occurs during ventricular diastole C) is called pulse pressure D) occurs during atrial systole
A) is called the systolic pressure
Which of these factors would increase peripheral resistance? A) increased blood viscosity B) decreased hematocrit C) increased vessel radius D) decreased blood volume
A) increased blood viscosity
The major factors determining blood pressure are
A) cardiac output and peripheral resistance
B) end systolic volume and end diastolic volume
C) the length of the blood vessels and the thickness of their walls
D) the level of carbon dioxide and the level of oxygen in the blood
A) cardiac output and peripheral resistance
This material typically cannot move through the capillary wall. A) carbon dioxide B) oxygen C) protein D) water
C) protein
Which of these pressures forces molecules out of capillaries? A) blood hydrostatic pressure B) blood osmotic pressure C) tissue hydrostatic pressure D) plasma colloid osmotic pressure
A) blood hydrostatic pressure
Molecules are moved out of capillaries by forces that push on the molecules from inside the capillary (blood hydrostatic pressure) or pull on them from outside the capillary (tissue osmotic pressure).
The colloid osmotic pressure of the blood is caused by
A) contraction of the heart ventricles
B) the presence of proteins in the plasma
C) the presence of sodium in the plasma
D) the presence of water in the plasma
B) the presence of proteins in the plasma
*The capillary walls are not permeable to the numerous, large plasma proteins. This creates an osmotic pressure gradient.
In a given capillary, the following set of conditions exists:
Blood hydrostatic pressure 12 mmHg
Blood osmotic pressure 28 mmHg
Tissue hydrostatic pressure -3 mmHg
Tissue osmotic pressure 1 mmHg
What is the net filtration pressure? A) -18 mmHg B) -12 mmHg C) -14 mmHg D) +38 mmHg
B) -12 mmHg
*Net filtration pressure = Net hydrostatic pressure - net osmotic pressure
In which choice is the factor on the left not correctly matched with its effect on the right?
A) increased heart rate; increased blood pressure
B) decreased stroke volume; decreased cardiac output
C) increased blood volume; increased blood pressure
D) decreased peripheral resistance; increased blood pressure
D) decreased peripheral resistance; increased blood pressure
*Any factor that decreases cardiac output or decreases peripheral resistance would decrease mean arterial pressure. MAP = CO x PR
If blood pressure is too low, the cardiovascular control center in the medulla oblongata attempts to compensate by causing
A) systemic arteriole dilation
B) decreased heart rate
C) increased contractility of the myocardial cells
D) decreased cardiac output
C) increased contractility of the myocardial cells
