distribution across capillaries

Question 1

starling foces

Answer 1

colloid osmotic pressure and capillary hydrostatic forces

established due to plasma protein concentration

Question 2

osmolarity of ECF = osmolarity of vasculature

Answer 2

this is to allow the free movement of water and electrolytes. it is the plasma protein concentration that establishes the forces.

Question 3

capillary hydrostatic pressure CHP

Answer 3

pushes fluid from vessels to –> ECF (ISF)
established by cardiac bp
higher pressure at arteriolar end = 45 mmHg
lower pressure at venous end = 15 mmHg

Question 4

colloid osmotic pressure COP

Answer 4

filters fluid from ECF –> vasculature
established by plasma protein concentration in vessels
higher at venous end = 27 mmHg
lower at arteriolar end = 25 mmHg

Question 5

arteriolar end pressure

Answer 5

CHP > COP

Question 6

venous end pressure

Answer 6

CHP < COP

Question 7

edema/hypoproteinurea

Answer 7

decreases in plasma proteins of the vasculature causes a decrease in COP
less fluid is filtered from ECF –> vasculature

Question 8

blood loss

Answer 8

causes a decrease in CHP

less fluid is pushed from vasculature –> ECF as the body attempts to use ECF to make up for lost fluids in vasculature

Question 9

increase in CHP

Answer 9

reasons include:

increased blood flow, increased blood volume and increased venous pressure

Question 10

increase in IFCOP

Answer 10

interstitial fluid COP increase is associated with thyroid dysfunction where osmotic agents result in fluid retention in the ECF.
non pitting edema

Question 11

decrease in COP

Answer 11

liver failure e.g. nephrotic syndrome associated with hyperproteinemia

Question 12

measuring body fluids

Answer 12

indicator dilution principle

Question 13

measuring plasma vol only

Answer 13

evans blue dye or radio iodinated albumin/fibrinogen

Question 14

measuring ECF vol only

Answer 14

NaCl, sucrose, inulin, mannitol

Question 15

measuring ICF

Answer 15

antipyrine, aminopyrine, heavy water, tritiated water

Question 16

to determine ICF

Answer 16

TBW - ECF

Question 17

to determine ISF

Answer 17

ECF - plasma volume

Question 18

sodium regulation

Answer 18

uptake at digestive system and correlated with diet

excretion at kidneys

Question 19

ADH sodium regulation

Answer 19

ADH regulates ECF osmolarity
where there is an increase in sodium this will cause water reabsorption at the kidneys and increase in ADH secreted by the pituitary
ADH vasoconstricts arterioles causing CHP to increase and push more fluid into ECF
regulators:
plasma osmolarity
blood pressure (drop in bp stimulates ADH)

Question 20

Aldosterone sodium regulation

Answer 20

aldosterone regulates ECF volume
drop in ECF volume causes sodium absorption and potassium excretion
sodium absorption causes reabsorption of water also
regulators:
angiotensin II
increases in plasma potassium

Question 21

ANP sodium regulation

Answer 21

Atrial natriuretic peptide causes sodium excretion.

inhibits ADH, aldosterone and thirst.