module 3 - 8.2 blood vessels

Question 1

what are blood vessels part of?

Answer 1

part of the closed circulatory systems

Question 2

what are the 5 types of blood vessels?

Answer 2

• arteries
• arterioles
• capillaries
• venules
• veins

Question 3

what do arteries and arterioles do with blood?

Answer 3

carry OXYGENATED blood AWAY from the heart to the body cells

Question 4

what do veins and venules do with blood?

Answer 4

carry DEOXYGENATED blood from the body cells INTO the heart

Question 5

where do capillaries go?

Answer 5

drain into venules, then into veins, then back to the heart

Question 6

arteries and arterioles carry oxygenated blood, except which?

Answer 6

• pulmonary artery
• umbilical artery
  both carry deoxygenated blood

Question 7

which parts of the body have no blood flow?

Answer 7

• cornea of the eye
• lens of the eye
• epithelium
• cartilage

Question 8

what are the components of a blood vessel?

Answer 8

• elastic fibres
• smooth muscle
• collagen

Question 9

what do elastic fibres do?

Answer 9

• they are made of elastin
• they stretch and recoil
• provide blood vessel with flexibility

Question 10

what does smooth muscle do?

Answer 10

contracts and relaxes changing size of the lumen
- NOT TO PUMP BLOOD

Question 11

what does collagen do?

Answer 11

provides structural support to maintain shape and volume of vessel

Question 12

what are the 3 layers to arteries, arterioles, venules and veins?

Answer 12

tunica externa - outer layer
tunica media - middle layer
tunica intima - inner layer

Question 13

what is the endothelium a part of?

Answer 13

the inner layer

Question 14

what is the tunica externa?

Answer 14

• outermost layer of artery or vein
• made of collagen fibres & elastic tissue
• has small blood vessels that supply large blood vessels

Question 15

what is the tunica media?

Answer 15

middle layer
- made of smooth muscle cells, elastic tissue, and collagen fibres

Question 16

what is the tunica intima?

Answer 16

• innermost layer
• has direct contact with blood flow
• made up of 1 layer of endothelial cells

Question 17

what is the composition of the tunica intima within elastic arteries?

Answer 17

• single layer of endothelium cells
• supporting layer of elastin rich collagen

Question 18

what is the composition of muscular arteries, arterioles, veins and venules?

Answer 18

single layer of endothelial cells

Question 19

what do arteries and arterioles do?

Answer 19

• carry blood at high pressure
• have narrow lumen (maintains pressure)
• thick elastic & muscle layers to expand & recoil as heart beats
• arterioles have greatest influence on local AND overall blood pressure, ‘adjustable nozzles’ to greatest pressure drop occurs

Question 20

what is the diameter of a capillary?

Answer 20

5-10µm (RBC travel in single file)

Question 21

how are substances exchanged from blood cells to surrounding tissue?

Answer 21

gaps in endothelium

Question 22

what are the 3 types of capillaries?

Answer 22

continuous capillaries
fenestrated capillaries
sinusoidal capillaries

Question 23

what are continuous capillaries?

Answer 23

endothelial cells produce uninterrupted lining (joined together)

Question 24

what are fenestrated capillaries?

Answer 24

have pores in endothelial cells (allows exchange to happen faster)

Question 25

what are sinusoidal capillaries?

Answer 25

open-pore capillary, wider openings in endothelium

Question 26

what are the adaptations of a capillary?

Answer 26

large SA - allows diffusion and metabolic demands to be met
cross sectional area is small - reduces rate of blood flow from artery/arteriole, allows enough time to exchange materials
endothelium is one cell thick - short diffusion pathway

Question 27

what do walls of veins contain?

Answer 27

lots of collagen, few elastic fibres and muscle

Question 28

what do venules contain?

Answer 28

no elastin, no elastic fibres, no smooth muscle

Question 29

what are valves?

Answer 29

act as one way blood flow system to prevent back flow

Question 30

what do large valves have?

Answer 30

have active muscle moving blood

Question 31

what are breathing movements?

Answer 31

occurs in the chest, this aids the movement of blood

Question 32

what happens if a vein wall becomes weakened?

Answer 32

valves may no longer close properly, allows backflow of blood, causes vein to become large and bumpy and VARICOSE

Question 33

when does a vein become varicose?

Answer 33

happens in superficial veins near skin surface in lower legs
- vicarious veins can be surgically removed without affecting blood flow

Question 34

what is glucose used for?

Answer 34

respiration in cells

Question 35

what do coronary arteries do?

Answer 35

carries blood to heart muscle