Arteries, veins and capilaries (BLOOD VESSELS)

Question 1

When blood flows from the heart to the organs it travels at a (?) pressure? through (?)

Answer 1

high pressure through arteries (A away)

Question 2

How are the arteries adapted to cope with this high pressure> 3

Answer 2

• thick wall
• muscle
• elastic fibre ( cope with surges of blood as the heart beats)

Question 3

Why do arteries sometimes narrow?

Answer 3

fatty substances can build up in the artery walls

Question 4

how can the problem of narrowing arteries be solved?

Answer 4

stent (metal mesh tube)

keeps arteries open making sure the blood can pass through to the heart muscles

Question 5

Advantage of stents?

Answer 5

lowers risk of a heart attack, if a blockage occurs in the coronary artery.. heart can be starved of oxygen if it narrows

Question 6

When blood flows from the organs to the heart it travels at a (?) pressure through (?)

Answer 6

low pressure, veins

Question 7

Organs (?) oxygen and blood (?) down, (?) its pressure

Answer 7

lose oxygen, blood flow slows down, loses its pressure

Question 8

How are the veins adapted to cope with low pressure. 3

Answer 8

thin wall
valves
valves push blood, keep it flowing in the right direction
(close= stop back, open= go forward
they have a bigger lumen (hole) help blood flow despite low pressure

Question 9

Arteries branch into the (?)

Answer 9

capillaries

Question 10

Capillaries do what? 2

Answer 10

1 carry blood extra close to every cell to exchange substances with them
2 supply food and oxygen, take away waste such as co2

Question 11

Capillaries features

Answer 11

one cell thick wall (increases rate of diffusion, smaller distance)