cardiovascular system-blood vessels and circulation: capillaries

Question 1

the contraction and relaxation of smooth muscles control the flow of

Answer 1

blood

Question 2

capillaries join together to form

Answer 2

venules–> veins, which have thin walls

Question 3

in veins smooth muscles in ________ contract to prevent backflow

Answer 3

in veins smooth muscles in Tunica Adventitia contract to prevent backflow

Question 4

_____ act as low pressure blood reservoirs

Answer 4

Veins act as low pressure blood reservoirs

Question 5

_______ nerves stimulates the _______ of veins

Answer 5

Sympathetic nerves stimulates the constriction of veins

Question 6

what arteries are elastic arteries

Answer 6

aorta
pulmonary artery

Question 7

Tunica media of these arteries contain a lot of

Answer 7

elastic fibers and few smooth muscles

Question 8

during ventricular systole

Answer 8

pressure within the heart rises
aortic semilunar valves open
blood flows in to aorta
walls of aorta and major arteries are stretched

Question 9

aorta acts as a

Answer 9

reservoir

Question 10

aorta’s walls store

Answer 10

energy from contraction of heart

Question 11

during ventricular diastole

Answer 11

pressure in the heart falls
semilunar valves are closed
walls of aorta recoil and propel blood onwards

Question 12

aorta acts as a

Answer 12

subsidiary pump

Question 13

aorta’s walls use the

Answer 13

energy previously stored from the heart’s contraction

Question 14

pulse wave

Answer 14

during systole as blood is pumped from the heart the distension and increase in pressure which starts in the aorta passes along the arterial system as a wave

Question 15

“the pulse” at the wrist

Answer 15

the expansion and subsequent relaxation of the wall of the radial artery

Question 16

blood vessels to take pulse

Answer 16

carotid artery
radial artery
brachial artery
dorsalis pedis artery- supplies dorsal surface of feet
femoral artery
popliteal artery
near the ankle joint
posterior tibial artery

Question 17

arterioles

Answer 17

less than 30 micrometer diameter

smallest of the muscular arteries with undefined tunica externa, and 1 or 2 layers of smooth muscles in tunica media

resistance vessels

Question 18

resistance vessels

Answer 18

responsible for maintenance of blood pressure

Question 19

what is an ex of resistance vessels

Answer 19

arterioles

Question 20

capillaries have the largest

Answer 20

total cross-sectional area and the lowest blood flow velocity for the exchange of substances between the blood and the cells

Question 21

in capillaries, exchange of ____ takes place

Answer 21

in capillaries exchange of substances take place

Question 22

in capillaries the wall is made up of a

Answer 22

single layer of endothelium and a basal lamina

Question 23

in capillaries what 2 layers are absent

Answer 23

tunica media
tunica adventitia

Question 24

capillaries form a

Answer 24

network among the cells of the body

Question 25

in the capillaries, there is continuous movement of

Answer 25

fluid through the arteriolar end of the capillaries in to the interstitial fluid and in to the capillaries at the venular end

Question 26

what dissolves into the ECF

Answer 26

nutrients, gases, water, and hormones present in the blood diffuses out in to the ECF

Question 27

what diffuses in to the capillaries

Answer 27

water dissolves wastes such as carbon dioxide diffuse in to the capillaries

Question 28

the capillaries help to regulate

Answer 28

body temperature by vasoconstriction and vasodilation

Question 29

capillaries are absent

Answer 29

epidermis of the skin
hair and nails
cornea of the eye
articular hyaline carilage

Question 30

network of capillaries

Answer 30

capillary bed (capillary plexus)

Question 31

precapillary sphincter

Answer 31

at the entrance of each capillary reduces or stops the flow blood

Question 32

capillary bed contains direct connections between

Answer 32

arterioles
venules

Question 33

collaterals

Answer 33

multiple arteries that supply blood to the capillary bed

Question 34

anastomosis

Answer 34

the fusion of two collaterial arteries

Question 35

sinusoids

Answer 35

dilated fenestrated capillaries

lumen is irregular

found in liver, spleen, and bone marrow

Question 36

cavernous tissue (sinus)

Answer 36

blood filled spaces lined by endothelium and surrounded by smooth muscle

present in the erectile tissue of penis, clitoris

Question 37

short term elevation of blood pressure

hormonal effects

Answer 37

increase cardiac output
increase peripheral vasoconstriction (epinephrine, norephinephrine, antidiuretic hormone, angiotensin 2)

Question 38

autoregulation of blood flow within tissues

Answer 38

adjusted by peripheral resistantce while cardiac output stays the same

Question 39

local vasodilators

Answer 39

accelerate blood flow at tissue level

Question 40

local vasodilators ex

Answer 40

low O2
high CO2
low pH (acids)
nitric oxide (NO)
high K+ or H-
chemicals released by inflammation (histamine)
elevated local temp

Question 41

local vasoconstrictors

Answer 41

prostaglandins and thromboxanes
released by damaged tissure
constrict precapillary sphincters
affect a single capillary bed

Question 42

baroreceptor reflex
when blood pressure rises, CV centers

Answer 42

decrease cardiac output
cause peripheral vasodilation

Question 43

baroreceptor reflexes
when blood pressure falls, CV centers

Answer 43

increase cardiac output
cause peripheral vasoconstriction

Question 44

chemoreceptors reflexes
peripheral chemoreceptors in

Answer 44

carotisd bodies and aortic bodies monitor blood

Question 45

central chemorecptors below medulla oblongata

Answer 45

monitor cerebrospinal fluid
control respiratory function
control blood flow to brain