Blood vessels

Question 1

what is the order of blood vessels?

Answer 1

artery –> arteriole –> capillaries –> venule –> vein

Question 2

what are the layers of blood vessels (vein and artery)?

Answer 2

from middle outwards,
lumen, tunica intima, tunica media, tunica externa

Question 3

describe the lumen of the artery

Answer 3

relatively narrow

Question 4

describe the tunica intima of the artery

Answer 4

endothelium (a very smooth layer of cells- squamous epithelium cells)

Question 5

describe the tunica media of the artery

Answer 5

contains elastic fibres, collagen fibres and smooth muscle

Question 6

describe the tunica externa

Answer 6

contains collagen fibres and some elastic fibres

Question 7

what is the tunica externa also sometimes called?

Answer 7

tunica adventitia

Question 8

in which direction do arteries carry blood?

Answer 8

Away from the heart

Question 9

what blood do arteries carry?

Answer 9

O2 blood except pulmonary artery and umbilical artery

Question 10

why is there more elastic fibres in aorta than arterioles?

Answer 10

because pressure has decreased

Question 11

what gives arteries continuous flow?

Answer 11

the elastic fibres stretch (collagen limits) to take larger blood vol tf continuous flow

Question 12

is the artery high or low pressure?

Answer 12

high

Question 13

what happens when the heart relaxes, in an artery?

Answer 13

elastic fibres recoil - pulse

Question 14

where is the only blood vessel where substances diffuse?

Answer 14

capilarries

Question 15

describe the lumen of a vein

Answer 15

relatively large

Question 16

describe the tunica media of a vein

Answer 16

very thin, contains some smooth muscle and elastic fibres

Question 17

describe the tunica externa of a vein

Answer 17

mostly collagen fibres

Question 18

in which direction does a vein pump blood?

Answer 18

to the heart

Question 19

what blood does a vein carry?

Answer 19

deO2 blood apart from pulmonary vein and umbilical vein

Question 20

does the vein have a pulse?

Answer 20

no because it has lower pressure than an artery (which does)

Question 21

how many veins have valve?

Answer 21

most of them- medium sized

Question 22

what are the function and structure of larger veins?

Answer 22

run between muscle which contracts to cause blood movement

Question 23

what is the function of a vein during breathing?

Answer 23

acts as a pump to move blood back to heart

Question 24

describe the lumen of a capillary

Answer 24

just big enough for RBC to squeeze along

Question 25

describe the wall of a capillary

Answer 25

wall made of squamous epithelium, one cell thick

Question 26

what do capillaries link?

Answer 26

arteriole to venules

Question 27

what is different about capillaries in CNS?

Answer 27

do not have fenestrations, have tight junctions

Question 28

what is the diameter of a capillary the same as?

Answer 28

the diameter of a RBC

Question 29

what do capillaries have which other blood vessels do not?

Answer 29

fenestrations

Question 30

what are fenestrations?

Answer 30

little gaps between cells
-make capillaries leaky

Question 31

what do fenestrations allow?

Answer 31

allow substances to pass through

Question 32

what do capillaries form?

Answer 32

extensive network through all the tissues in the body