unit 2.5: the structure and function of arteries, capillaries and veins

Question 1

what is included in the cardiovascular system

Answer 1

the heart (a muscular pump)
blood (a fluid connective tissue)
blood vessels (arteries, capillaries and veins)

Question 2

what does blood travel away from the heart in

Answer 2

arteries

Question 3

what does blood travel to the heart in

Answer 3

veins

Question 4

what is there a decrease in as blood travels away from the heart

Answer 4

blood pressure

Question 5

what is the biggest and main artery

Answer 5

aorta

Question 6

arterial branches of the aorta supply what

Answer 6

oxygenated blood

Question 7

what is the largest vein formed from the joining of other veins

Answer 7

vena cava

Question 8

what does the vena cava supply

Answer 8

deoxygenated blood to the heart

Question 9

what is the name of the artery that supplies blood to the heart

Answer 9

coronary artery

Question 10

what takes the deoxygenated blood back into circulation from the heart

Answer 10

coronary vein

Question 11

what is the exception in the pulmonary system

Answer 11

the pulmonary vein carries oxygenated blood
the pulmonary artery carries deoxygenated blood

Question 12

what is another exception in the cardiovascular system

Answer 12

the haptic portal vein

Question 13

what does the haptic portal vein do

Answer 13

carried blood from the capillary bed of the intestines to the liver

Question 14

how many blood vessels does the liver have associated with it

Answer 14

3

Question 15

what is the central cavity of blood vessels called

Answer 15

lumen

Question 16

what is the lumen lined by

Answer 16

thin layer of cells called the endothelium

Question 17

what is the structure of arteries

Answer 17

inner and outer layer of connective tissue containing elastic fibres
a thick middle layer of smooth muscle with more elastic fibres
a narrow lumen

Question 18

what does the what does the thick smooth muscle and elastic fibres allow the arteries to do

Answer 18

pulsate, stretch and recoil which accommodates the surge after contraction of the heart

Question 19

what can smooth muscle in the walls of arterioles do

Answer 19

contract or become relaxed

Question 20

what does this relaxation or contraction in arterioles cause

Answer 20

vasoconstriction or vasodilation

Question 21

what does vasoconstriction or vasodilation do

Answer 21

controls the blood flow to allow changing demands to body tissue

Question 22

what happens to arterioles during strenuous exercise

Answer 22

vasodilation to skeletal muscles to allow more blood flow

vasoconstriction to intestines to decrease blood flow

Question 23

what is the structure of veins

Answer 23

outer muscular layer of connective tissue with elastic fibres thinner than those in arteries due to blood being of lower pressure
wider lumen
contains valves to prevent back flow

Question 24

how thick are capillaries

Answer 24

1 cell thick

Question 25

what is the pathway of blood vessels blood follows

Answer 25

glucose + oxygen: artery > arterioles > capillaries > body tissue waste (urea) + CO2: body tissue > capillaries > venules > veins

Question 26

where does exchange of materials take place

Answer 26

through capillary walls

Question 27

what fluid is where glucose and oxygen are supplied to cells

Answer 27

tissue fluid

Question 28

what is the composition of plasma fluid

Answer 28

watery, yellow fluid contains dissolved substances such as glucose, amino acids, blood cells, platelets and plasma proteins

Question 29

what is the composition of tissue fluid

Answer 29

the same as plasma fluid, however does not contain plasma proteins

Question 30

why does tissue fluid not contain plasma proteins

Answer 30

these are too big to diffuse through capillary walls

Question 31

how does exchange of materials work

Answer 31

pressure filtration

Question 32

how does pressure filtration work

Answer 32

higher pressure in arterioles caused pressure filtration out of the capillaries into tissue fluid as blood is forced into narrow capillaries it undergoes pressure filtration and much of the plasma is squeezed through the thin walls into surrounding cells

Question 33

how does tissue fluid get the useful substances to body cells

Answer 33

diffusion down a concentration gradient (high volume of useful substances to an area without as many)

Question 34

how do body cells get rid of waste products

Answer 34

diffusion down a concentration gradient

Question 35

how does tissue fluid return to the circulatory system

Answer 35

by osmosis (high concentration to low) into capillaries at the venule end

Question 36

what does tissue fluid have a higher concentration of than plasma fluid and why

Answer 36

water concentration as it does not contain plasma proteins which are too big to be filtered

Question 37

does all tissue fluid return to the body via capillaries

Answer 37

no

Question 38

how does the excess tissue fluid return to the body

Answer 38

through the lymphatic system

Question 39

what does tissue fluid become when it is absorbed by thin walled lymphatic vessels

Answer 39

lymph

Question 40

how is the flow of lymph brought about

Answer 40

when vessels are compressed due to muscle contraction when breathing and body movement

Question 41

what do larger lymph vessels contain

Answer 41

valves to prevent backflow

Question 42

how do lymph vessels return contents to the blood

Answer 42

via 2 lymphatic ducts, which enter the veins coming from the arms