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
