blood vessels

Question 1

Name the 4 components of arteries and list their functions

Answer 1

Adventitia - structural strength and tethers the vessels in place
Elastin - gives mechanical strength
Endothelium - filtering interface
Smooth Muscle - supplies the vessels with contractile power and regulates diameter of lumen

Question 2

why must MAP be maintained

Answer 2

so that the arteries can provide oxygenated blood to wherever it is required

Question 3

what is active hyperaemia

Answer 3

the increase of blood flow according to metabolic needs of the tissue in question

Question 4

why are capillaries numerus

Answer 4

so they can provide a large SA

Question 5

name and describe 3 capillary endothelial arrangements

Answer 5

Continuous - muscle, nerve, fat
fenestration - glands, kidney, intestines
discontinuous - liver, bone, marrow, spleen

Question 6

is hydrostatic pressure higher or lower at the arterial end

Answer 6

higher

Question 7

is colloid osmotic pressure higher or lower at the arterial end

Answer 7

Trick - its constant

Question 8

when does filtration take place

Answer 8

when hydrostatic pressure exceeds osmotic pressure

Question 9

name some features of venous walls

Answer 9

wider lumen, less elastic tissue, more distensible, thinner walls, valves

Question 10

how much of your blood is in your veins at rest

Answer 10

60%

Question 11

when blood is needed what happens to the veins

Answer 11

they become stiffer and force more blood into the heart, frank starling mechanism

Question 12

how do veins push blood if they do not constrict

Answer 12

they change complience, skeletal muscles can also act as a pump