Chapter 20: Blood Vessels and Circulation

______ shock can be produced by hemorrhage, severe burns, or dehydration.

Hypovolemic

The contraction of skeletal muscles, plays an important role in the movement of blood in the veins.

True

Valves in veins

cause venous blood flow to go in only 1 direction

High carbon dioxide levels and low pH in blood of the carotid arteries will stimulate

chemoreceptors to activate the vasomotor center

Which is the most common type of capillary?

continuous

Excitation of the vasomotor center results in

increase sympathetic activity and predominantly more vasoconstriction than vasodilation.

The medullary ischemic reflex results in

increased circulation to the brain

Blood colloid osmotic pressure is largely due to

the proteins in the blood, and it promotes reabsorption

The velocity of blood flow decreases when

viscosity increases

If someone's blood pressure were listed as 125/75 mmHg, then their pulse pressure would be

50 mmHg

What is the mean arterial pressure for a person with 110 and 65 mm HG as systolic and diastolic pressure, respectively?

80 mm Hg

Myocardial infarction can lead to ______ shock.

Cardiogenic

_____ would not increase capillary filtration.

Dehydration

A vasodilator causes a decrease in local blood flow at a capillary bed.

False

An increase in blood vessel diameter would lead to a decrease in blood flow.

False

________ have the thickest tunica media.

Large arteries

Blood flow through a capillary bed is regulated by precapillary sphincters.

True

Increased capillary filtration, reduced reabsorption, or obstruction of lymphatic drainage can lead to edema.

True

______ does not contribute to venous return.

Widespread vasodilation

If someone suffered from hypertension, such that the blood pressure in their capillaries were elevated, their net filtration pressure would be

above normal

Angiogenesis

allows for us an increase in the perfusion of a local tissue

All of these increase BP (norepinephrine, ADH, angiotensin II, and aldosterone) except

atrial natriuretic peptide

The most important force driving reabsorption at the venous end of a capillary is

blood colloid osmotic pressure

The most important force driving filtration at the arterial end of a capillary is

blood hydrostatic pressure

As blood moves from the arterial end to the venous end of a capillary, net filtration pressure

decreases, as blood hydrostatic pressure decreases

Blood flow is

directly related to both the pressure gradient and the resistance

Peripheral resistance is

directly related to vessel length and inversely related to vessel radius

The largest arteries in the body are classified as

elastic arteries

As an arterial pathway moves farther from the heart, the arteries

get smaller

All these can lead to edema (obstruction of lymphatic vessels, liver disease, famine, and hypertension) except

hyperproteinemia

Reactive hyperemia is a result of ______ to increase perfusion into a tissue.

local control

The vasomotor center of the _____ controls blood vessels throughout the body.

medulla oblongata

Concerning the exchange between blood and interstitial fluid at systemic capillaries

more fluid is filtered than reabsorbed

A bee sting can trigger a massive release of histamine, which causes ______ and a ________ in arterial blood pressure.

vasodilation; decrease

Blood pressure is lowest in

veins