blood vessels

Question 1

what are the parts of the artery

Answer 1

-Lumen
-Endothelium
-Smooth muscle and elastic tissue
-Connective tissue

Question 2

what is the role of the lumen in the artery

Answer 2

-relatively narrow to maintain a high blood presssure

Question 3

what is the role of the endothelium in the artery

Answer 3

-forms the inner layer (known as tunica interna) of an artery wall
-consists mainly of endothelial (same as epithelial except in blood cells) cells to form a lining

Question 4

what is the inner layer of an artery wall or vein wall known as

Answer 4

tunica interna

Question 5

what is the outer medium layer of an artery or vein known as

Answer 5

tunica media

Question 6

what is the role of the smooth muscle and elastic tissue in the artery

Answer 6

-forms middle, thickest layer of an artery wall (tunica media)
-enable artery to flex (muscle contracts) and stretch (elastic tissue)
-overall role to maintain a high blood pressure

Question 7

what is the role of the connective tissue in an artery

Answer 7

-form the outer layer of an artery wall (tunica externa)
-consists of tough collagen fibres which provide strength and durability
-overall role to withstand a high pressure

Question 8

what is the outer layer of a artery and vein known as

Answer 8

tunica externa

Question 9

what do veins contain that is unlike capillaries and artery’s and what is the role

Answer 9

-valves
-prevent backflow and pooling of blood in lower parts of body due to gravity

Question 10

what is the role of the lumen in the vein

Answer 10

-is relatively larger as there is no need to maintain a high prerssure

Question 11

what is the role of the endothelium in the vein

Answer 11

-form the inner layer (tunica interna) of a veins wall
-forms lining from endothelial cells

Question 12

what is the role of the smooth muscle and elastic tissue in the vein

Answer 12

-forms the tunica media like artery
-however is much thinner as it does constrict but much less

Question 13

what is the role of the connective tissue in a vein

Answer 13

-same as an artery however much less of it as doesn’t need to be as strong

Question 14

how does blood flow through veins?

Answer 14

-Skeletal muscles contract
-Blood beyond site of contraction is forced towards the heart
-opening valves
-valves behind contraction site prevent blood being forced away from heart

Question 15

role of lumen in capillary

Answer 15

-very narrow (diameter of one red blood cell)
-slows down blood flow so substances can diffuse in and out
-has a high SA to V ratio

Question 16

role of the endothelium in a capillary

Answer 16

-very thin (one cell thick) to allow efficient diffusion

Question 17

role of the basement membrane in a capillary

Answer 17

-is not a layer of cells
-rather, anchors capillaries in position within the tissues

Question 18

parts of a capillary

Answer 18

-lumen
-endothelium
-basement membrane

Question 19

relative size of lumen of all three vessels

Answer 19

Arteries>veinbs>capillaries

Question 20

relative thickness of walls of all three vessels

Answer 20

Arteries>veins>capillaries

Question 21

what are the tissues of the walls of capillaries

Answer 21

-only one layer of endothelial cells

Question 22

what are the tissues in the walls of arteries and veins

Answer 22

-endothelium
-elastic tissue
-smooth muscle and connective tissue

Question 23

difference between the tissues in the walls of arteries and veins

Answer 23

-veins have less smooth muscle and elastic tissue than arteries
-because they deal with low-pressure blood return and rely on passive mechanisms (like muscle pumps and valves) for blood movement

Question 24

direction of flow of blood (relative to the heart) in all three vessels

Answer 24

Arteries- Away
Capillaries-Between arteries and veins where exchange/diffusion occurs
Veins- Towards the heart

Question 25

type of blood (o2 content) in arteries

Answer 25

-oxygenated blood from heart to rest of body -except pulmonary artery from heart to lungs for re-oxygenation

Question 26

type of blood (o2 content) in capillaries

Answer 26

-oxygenated blood from arties into capillaries in tissues -deoxygenated blood from capillaries into veins to return to heart

Question 27

type of blood (o2 content) in veins

Answer 27

-deoxygenated blood back to heart after delivery of O2 and pickup of CO2 -except pulmonary veins which transport oxygenated blood from lungs to left atrium of heart

Question 28

presence of valves in all 3 vessels

Answer 28

1)arteries- none 2)capillaries- none 3)veins- has valves

Question 29

blood pressure in all 3 vessels

Answer 29

1)Arteries= high 2)Capillaries= low to facilitate exchange 3)Veins= very low as blood retuning to heart relies on muscle contractions and valves

Question 30

role and structure of the arteriole

Answer 30

-contain smooth muscle to constrict diameter of arteriole to divert flow of blood to regions of body that need O2 -distributes blood from artery to capillaries

Question 31

role and structure of the venule

Answer 31

-collect blood from capillary bed into the veins -thin layers of elastic + muscle tissue and endothelium on outside -thin outer layer of collagen