CVS-blood volume

Question 1

why is sufficient blood volume necessary?

Answer 1

to maintain adequate perfusion to all tissues in the body

Question 2

what is ischemia?

Answer 2

inadequate perfusion

Question 3

what is infarction?

Answer 3

necrosis due to prolonged ischemia

Question 4

what are the 3 components of whole blood?

Answer 4

• blood plasma
• buffy coat
• RBCs

Question 5

what is blood plasma composed of?

Answer 5

• water

- liquid ECM-contains water/ proteins

Question 6

what is the buffy coat made up of?

Answer 6

WBCs

platelets

Question 7

what % of blood does plasma make up?

Answer 7

55%

Question 8

which components sink to the bottom in centrifugation?

Answer 8

denser components-RBCs

Question 9

what 3 things do both veins and arteries have?

Answer 9

• tunica intima (endothelium and sub-endothelium)
• tunica media
• tunica externa

Question 10

what structure is excluisve to arteries?

Answer 10

internal elastic lamina of the tunica intima-for elastic recoil for high BP

Question 11

which structure is exclusive to veins?

Answer 11

valves

Question 12

what is the role of valves?

Answer 12

prevent backflow of blood under low BP

Question 13

name the 3 types of capillaries

Answer 13

• continuous
• fenestrated
• discontinuous

Question 14

what is the structure of continuous capillaries?

Answer 14

-contain pericytes–>cells that wrap around the endothelium of vessels to maintain homeostatic and haemostatic functions

Question 15

where are continuous capillaries found?

Answer 15

• blood-brain barrier

- dermis

Question 16

how much more permeable are fenestrated capillaries compared with continuous capillaries?

Answer 16

x10

Question 17

what do fenestrated capillaries allow?

Answer 17

fluid exchange-essential in kidneys

Question 18

what do discontinuous capillaries allow?

Answer 18

blood cell transfer

eg bone marrow, liver, spleen

Question 19

where are discontinuous capillaries found?

Answer 19

sinusoids