Blood Vessels and Circulation

Question 1

5 classes of blood vessels

Answer 1

arteries

arterioles

capilleries

venules

veins

Question 2

arteries

Answer 2

carry blood away from heart

high pressure

thicker tunica media than tunica externa

small lumen

Question 3

arterioles

Answer 3

are smallest branches of arteries

little or no tunica

have thin or incomplete tunica media

regulate the distribution of flow of blood to capillary beds

Question 4

capillaries

Answer 4

small blood vessels

location of exchange between blood and interstitial fluid

Question 5

venules

Answer 5

collect blood from capillaries

Question 6

veins

Answer 6

return blood to heart

lower pressure (works against gravity)

thinner: tunica externa thicker than tunica media

larger lumen

has valves

Question 7

largest blood vessels

Answer 7

pulmonary trunk

aorta

Question 8

smallest blood vessels

Answer 8

capillaries

Question 9

tunica externa

Answer 9

outermost layer

elastin and collagen strengthens,

anchor contains nerves and tiny blood vessels

Question 10

tunica media

Answer 10

middle layer

circular smooth

vaso-constriction/dilation

Question 11

tunica intima

Answer 11

innermost layer

endothelium

minimize friction

Question 12

lumen

Answer 12

interior opening of the vessel

Question 13

capillary network

Answer 13

capillary bed or capillary plexus connect 1 arteriole and 1 venule

Question 14

capillary sphincter

Answer 14

guards entrance to each capillary

opens and closes, causing capillary blood to flow in pulses

vasomotion

bloodflow in capillary beds constantly change routes

Question 15

medium sized veins

Answer 15

thin tunica media and frew smooth muscle cells

tunica externa with longitudinal bundles of elastic fibers

Question 16

large veins

Answer 16

have all 3 tunica layers

thick tunica externa

thin tunica media

Question 17

vein valves

Answer 17

folds of tunica intima prevent blood from flowing backward

compression pushes blood toward heart

Question 18

capillary bed:
at arterial end

Answer 18

fluid moves out of capillarie

into interstitial fluid

Question 19

capillary bed:

at venous end

Answer 19

fluid moves into capillary

out of interstitial fliud

Question 20

excess fluid in capillary bed goes in _________________

Answer 20

the lymphatic vessel

Question 21

systolic pressure

Answer 21

peak arterial pressure during ventricular systole

Question 22

diastolic pressure

Answer 22

minimum arterial pressure during diastole

Question 23

pulse pressure

Answer 23

difference between systolic pressure and diastolic pressure

Question 24

vasodilation

Answer 24

the relaxation of arterial smooth muscle enlarging the lumen

Question 25

vasoconstriction

Answer 25

the contraction of arterial smooth muscle by ANS

Question 26

smaller vessels contribute to ________

Answer 26

the most resistance

Question 27

blood viscosity

Answer 27

determined by the ratio of RBC’s to plasma volume

Question 28

venous retrurn

Answer 28

amount of blood arriving at right atrium each minute

Question 29

low venous resistance

Answer 29

assisted by muscular compression of preipheral veins

the respiratory pump

Question 30

compression of skeletal muscle pushes blood ___________ the heart

Answer 30

toward

Question 31

if blood pressure is too low

Answer 31

vessels collapse and blood flow stops

tissue dies

Question 32

if blood pressure is too high

Answer 32

vessels will stiffen

capillary bed may rupture

Question 33

3 regulatory mechanisms

Answer 33

autoregulation

neural regulation of blood pressure

hormonal regulation of blood pressure

Question 34

autoregulation

Answer 34

causes immediate homeostatic adjustment

physical changes

vaso dilation/constriction

Question 35

neural regulation of blood pressure

Answer 35

ANS regulates blood pressure through baroreceptors reflexes and chemoreceptor reflexes

Question 36

hormonal regulation of blood pressure

Answer 36

long term regulation of blood flow

Question 37

3 effects of light exercise

Answer 37

extensive vasodilation

venous return increases

cardiac output rises

Question 38

5 effects of heavy exrecise

Answer 38

activates sumpathetic nervous system

cardiac output increases to maximum

restricts blood flow

redirects blood flow to skeletal muscles, lungs and heart

blood supply to brain is unaffected

Question 39

lactic acid and low levels of O₂

Answer 39

dilate coronary vessels

increase coronary blood flow

Question 40

epinephrine

Answer 40

dilates coronary vessels

increases heart rate

strengthens contractions