Blood vessels

Question 1

what are pre-capillary sphincters

Answer 1

controls blood flow to specific capillary beds selectively

Question 2

what is smooth muscle

Answer 2

supplies the vessels with contractile power and regulates lumen diameter

Question 3

what is the endothelium

Answer 3

filtering interface between blood and the body

Question 4

what is elastin for

Answer 4

gives vessels mechanical strength and their elastic properties

Question 5

what is adventitia

Answer 5

provides structural strength and tethers the vessels in place

Question 6

what are arterioles responsible for

Answer 6

altering the levels of resistance to blood flow in order to distribute the available amount of blood

Question 7

what do conduits do to divert blood

Answer 7

they change their shape to restrict bloodflow

Question 8

what is active hyperamia

Answer 8

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

Question 9

what is flow auto regulation

Answer 9

concerns with the maintenance of blood flow rather than changing it, blood to brain has to be maintained for example as to not enlarge

Question 10

what is myogenic regulation of arterial diameter

Answer 10

increase in pressure leads to muscle stretch that is followed by constriction, myogenic response prevents flow from getting to high

Question 11

describe capillaries

Answer 11

there are numerous of them all across the body and are one cell thick to facilitate diffusion

Question 12

what dictates the velocity of blood flow

Answer 12

the total cross sectional area of capillaries not individual capillaries

Question 13

is the velocity of capillaries high or low

Answer 13

low

Question 14

where are capillaries found

Answer 14

surrounding every muscle fibre

Question 15

when does filtration take place

Answer 15

when hydrostatic pressure exceeds colloid osmotic pressure

Question 16

when does absorption take place

Answer 16

when colloid osmotic pressure exceeds hydrostatic pressure

Question 17

characteristics of veins compared to arteries

Answer 17

larger diameter, have valves, less elastic tissue, thinner walls, less smooth muscle

Question 18

what are characteristics of healthy veins

Answer 18

flow is only towards heart, back flow is prevented by shut valves

Question 19

what are characteristics of diseased veins

Answer 19

allow blood flow to move in opposite direction, can cause blood to accumulate in extremities

Question 20

how much blood is in veins

Answer 20

about 60% of total blood volume

Question 21

what is the pressure of blood in veins

Answer 21

only ~10mmHg

Question 22

what is the veins contribution level

Answer 22

not as active as arteries but ability to change from a reservoir to a condyle plays a big role

Question 23

how is central venous pressure determined

Answer 23

blood volume and compliance

Question 24

info of changing compliance of a vein on onenote

Question 25

how does the skeletal muscle pump work

Answer 25

compression on the veins by muscle contraction pushes blood towards the heart

Question 26

how does the respiratory pump work

Answer 26

the diaphragm contracts and moves downwards increasing the volume of the thoracic cavity and decreasing volume of abdominal cavity

Question 27

what do lymph vessels do

Answer 27

collect filtered fluid from interstitial space and return to circulating blood volume

Question 28

where are lymph vessels

Answer 28

they match the veins but aren't by any arteries

Question 29

what is oedema

Answer 29

accumulation of excess fluid in interstitial spaces, filtration exceeds lymphatic drainage