Ch. 14 HW: Physiology

The mean arterial pressure of a patient with a pulse pressure of 20 mmHg, and a blood pressure of 100/60 mmHg would be approximately:

67

Approximately what percent of fluid that exits in the capillaries at the arterial end reenters the capillaries at the venous end?

90%

Which of the following types of medications might be useful in treating high blood pressure?

A medication that reduces blood volume by increasing urination

Which do you expect to have the lowest blood pressure?

A vein leading directly to the right atrium

In which of these blood vessels will the blood encounter the highest resistance?

An arteriole with a diameter of 0.25 millimeters

Caffeine is a positive chronotropic agent. What effect on cardiac output can we expect in an individual who just drank a large cup of caffeinated coffee?

An increase in cardiac output

Digoxin is a positive inotropic agent that can be administered intravenously. What effect can be predicted in a patient who is treated with digoxin?

An increase in stroke volume

Blood vessel walls contain elastin, a protein that allows the vessel to stretch under high pressure. Which type of blood vessel do you expect will have the highest concentration of elastin in its walls?

Arteries

As training progresses and blood viscosity increases, what will happen to resistance and blood flow in the athlete?

Blood flow will decrease as peripheral resistance increases, so the athlete's heart will have to work harder to compensate.

Exercise triggers an increase in sympathetic activity to the heart. What effect, if any, will this have on cardiac output?

Both "Sympathetic activity will cause an increase in heart rate, which will increase cardiac output" and "Sympathetic activity will cause an increase in ventricular contraction strength, which will increase cardiac output" are true.

As blood vessel length increases, what happens to peripheral resistance and blood pressure?

Both peripheral resistance and blood pressure increase

Arteriosclerosis is a stiffening of the arteries, making them less able to distend. Which of the following lifestyle recommendations would help a patient with this diagnosis prevent high blood pressure, and why?

Decreasing sodium intake, to decrease blood viscosity and therefore decrease resistance to flow

Which of the following is TRUE regarding hypertension and the loss of elastin?

If the arteries become less stretchy, the heart will have to work harder to eject blood

When taking blood pressure using a sphygmomanometer, which of the following is true of the diastolic BP?

It is recorded after the last pulse sound is heard

Nitric oxide is released by exercising muscle cells and causes vasodilation in nearby blood vessels. What effect (if any) will nitric oxide have on blood flow?

Nitric oxide causes an increase in local blood flow.

As training progresses and blood viscosity increases, what will happen to peripheral resistance in the athlete?

Peripheral resistance will increase.

As the muscles of the legs repeatedly contract and relax, what effect, if any, will this have on blood flow?

Repeated contraction of the leg muscles will increase venous return.

During exercise, the amount of blood that returns to the heart increases dramatically. What change (if any) can be predicted about stroke volume?

Stroke volume will increase.

Baroreceptors are located in the

aorta and carotid arteries.

Chemoreceptors detect all of the following except

blood pressure.

Chemoreceptors are located in the

carotid and aortic bodies.

Heart rate will increase as a result of

decreased blood oxygen.

Peripheral resistance is __________ related to vessel length, and __________ related to vessel radius.

directly; inversely

The kidneys help regulate blood volume by increasing or decreasing the amount of urine produced. If a person is dehydrated, there is a(n) _____________ in plasma osmolality, which causes a(n) ____________ in ADH production, stimulating the kidneys to reabsorb water from the filtrate.

increase; increase

During exercise, the rate of venous return of the blood __________, causing a(n) __________ in stroke volume.

increases; increase

The heart contains a large amount of __________ and __________; this indicates that it is highly specialized for __________.

mitochondria; myoglobin; aerobic respiration

According to the Starling Law, the __________ effects on heart rate and contractility include decreasing the rate of contraction and increasing the filling time, resulting in a stronger contraction.

parasympathetic

Fluids reenter the capillaries at the venous end because

the hydrostatic pressure of the interstitial fluid is higher at the venous end than it is at the arterial end.

Fluids leave the capillaries at the arterial end because

the net filtration pressure of the blood is higher at the arterial end than it is at the venous end.

The sum of all the vascular resistance within the systemic circulation is called the

total peripheral resistance.

Action potentials are conducted from the baroreceptors to the brain via the

vagus and glossopharyngeal nerves.

The action potential from the brain to the heart travels along the

vagus nerve.