APII Ch. 21 Study Guide

which blood vessels carry blood away from the heart? which blood vessels carry blood to the heart?

arteries; veins

list the layers of blood vessel walls from deep to superficial

tunica intima, tunica media, and tunica adventitia

what happens to a blood vessel’s diameter when the smooth muscle in the wall contracts? what happens to a blood vessel’s diameter when the smooth muscle in the wall relaxes?

decreases; increases

why are artery walls typically thicker than in veins?

the tunica media contains more smooth muscle and elastic fibers than a vein does

what is the name of the force that opposes blood flow?

resistance

what is an aneurysm?

a bulge in the weakened arterial wall

what is arteriosclerosis?

a thickening and toughening of arterial walls

what is a scientific term for a stroke?

cerebrovascular accidents (CVA)

what are plaques?

lipid deposits

what is the difference between continuous and fenestrated capillaries?

continuous: the endothelium is a complete lining; fenestrated: contain “windows”, or pores, that penetrate the endothelial lining

define angiogenesis

the formation of new blood vessels from preexisting vessels and occurs under the direction of vascular endothelial growth factor (VEGF)

what is the function of vein valves?

prevent blood from flowing back toward the capillaries

what is deep vein thrombosis?

results when venous blood flow slows to a crawl and it triggers coagulation

what is a pulmonary embolism?

a potentially fatal condition in which the clots may end up in the lungs

which two forces determine capillary blood flow?

pressure and resistance

which force is directly proportional to blood flow? which force is inversely proportional to blood flow?

pressure; resistance

what occurs during capillary exchange?

the transfer of liquid and solutes between the blood and interstitial fluid

define blood pressure

a force exerted against vessel walls by the blood in the vessels

what is capillary hydrostatic pressure?

the pressure of blood within capillary walls

what is venous pressure?

the pressure of blood within the venous system

list the three combined factors that determine the total peripheral resistance of the cardiovascular system

vascular resistance, blood viscosity, and turbulence

name two factors that determine the amount of friction

vessel length and internal vessel diameter

what effect on friction, and therefore vascular resistance, does increasing the length of a blood vessel have?

increases friction

what effect on friction, and therefore vascular resistance, does increasing the luminal diameter of a blood vessel have?

decreases friction

what effect on resistance does viscous blood and turbulent blood have?

increase resistance to blood flow

when taking someone’s blood pressure, what does the top number and bottom number represent?

top number: systolic pressure; bottom number: diastolic pressure

define hypertension and hypotension

hypertension: abnormally high blood pressure; hypotension: abnormally low blood pressure

the mean arterial pressure declines as the arterial branches become smaller and more numerous. what effect does this have on blood pressure?

decreases

define venous return

the amount of blood arriving at the right atrium each minute

what two factors assist the low venous pressures in propelling blood toward your heart?

skeletal pump and respiratory pump

where do all gaseous and chemical exchanges between blood and interstitial fluid take place?

across capillary walls

list three important processes that move materials across typical capillary walls

diffusion, filtration, and reabsorption

define filtration

the removal of solutes as a solution passes through a porous membrane

what process is used for reabsorption?

osmosis

you are measuring pressures in a capillary and find that the CHP is 37mmHg and BCOP is 23 mmHg. what type of movement, if any, would occur at this part of the capillary?

net filtration

what type of movement, if any, would occur at a capillary if the NFP equaled 0?

no movement

why doesn’t BCOP change along the length of a capillary?

the large plasma proteins, primarily albumin, which contribute most to this pressure, are unable to cross the capillary wall and therefore maintain a relatively constant concentration throughout the capillary, regardless of the location along its length

since we don’t have enough blood to maintain adequate blood flow to all the capillaries in the body, homeostatic mechanisms operating at the local, regional, and systemic levels adjust blood flow through the capillaries to meet the demands of peripheral tissues. list three homeostatic mechanisms that accomplish this

autoregulation, neural mechanisms, and endocrine mechanisms

which of the mechanisms causes immediate, localized homeostatic adjustments to blood flow?

autoregulation

where is the cardiovascular center located in the brain?

medulla oblongata

which activities does the vasomotor center control?

sympathetic motor neuron activities

where are baroreceptors associated with the central regulation of blood flow located in the body? what do they monitor?

in the walls of the carotid sinuses, the aortic arch, and the wall of the right atrium; the degree of stretch in the walls of expandable organs

when blood pressure rises, the increased output from the baroreceptors alters activity in the cardiovascular center and produces two major effects. what are they?

a decrease in cardiac output and widespread peripheral vasodilation

when blood pressure falls below normal, the decreased output from the baroreceptors alters activity in the cardiovascular center and produces two major effects. what are they?

an increase in cardiac output and widespread peripheral vasoconstriction

where are chemoreceptors associated with central regulation of blood flow located in the body? what do they monitor?

in the carotid bodies and the aortic bodies; the composition of arterial blood

list five hormones that function in central regulation of blood flow

antidiuretic hormone, angiotensin 2, erythropoietin, ANP, BNP

what effect on blood vessels does the release of EPO have? does this increase or decrease blood pressure?

causes vasoconstriction, thereby increasing blood pressure

what effect on blood volume and blood pressure does the release of ANP and BNP produce?

reduce blood volume and blood pressure

what are three organs where special circulation occurs?

brain, heart, and lungs

list three changes to the cardiovascular response that occur during light exercise

extensive vasodilation occurs

during strenuous exercise, what three organs have an increase in blood flow?

skeletal muscles, heart, and skin

why do you think each of these organs receive additional blood?

these organs require more oxygen and nutrients to meet the increased metabolic demands of physical activity

which type of cholesterol is considered “bad” cholesterol? how does exercise lower cholesterol levels?

low-density lipoprotein (LDL); by stimulating enzymes that help move those proteins

when a person is hemorrhaging, there are a few cardiovascular system short-term responses that promote elevation of blood pressure. what effect do these have on cardiac output on vessel diameter?

increase cardiac output and extend peripheral vasoconstriction

name the major vessels

left and right pulmonary arteries and pulmonary veins

where does the systemic circuit begin? where does it end?

begins at the left ventricle and ends at the right atrium

what blood vessel begins at the aortic valve of the left ventricle?

ascending aorta

what two parts of the aorta are connected by the aortic arch?

ascending aorta and descending aorta

name the three elastic arteries that originate along the aortic arch that deliver blood to the head, neck, shoulders, and upper limbs

brachiocephalic trunk, left common carotid artery, and left subclavian artery

what parts of the body receive blood from the subclavian artery?

arms, chest walls, shoulders, back, and CNS

which blood vessel are you feeling when checking for a pulse along either side of the windpipe?

carotid artery

which blood vessels deliver oxygenated blood to the brain?

internal carotid arteries

define cerebrovascular accident (stroke)

interruptions of the vascular supply to a portion of the brain

the neck and the limbs generally have two sets of peripheral veins, one superficial and the other deep. what important function does this serve?

efficient blood drainage from the skin and surrounding tissues to the heart

which great vessel receives blood from all the body’s systemic veins (except the cardiac veins)?

the superior vena cava or inferior vena cava

which part of the vena cava receives blood from the tissues of the head, neck, chest, shoulders, and upper limbs?

superior vena cava

which part of the vena cava collects most of the venous blood from organs inferior to the diaphragm?

inferior vena cava

what is the largest vessel of the hepatic portal system?

hepatic portal vein

which blood vessels bring blood to the placenta?

umbilical arteries

which blood vessel transfers blood from the placenta?

umbilical vein

what occurs at the foramen ovale?

blood can flow freely from the right atrium to the left atrium, but any backflow closes the valve and isolates the two chambers from one another

a short-circuit exists between the pulmonary and aortic trunks. what are they connected by?

the ductus arteriosus