Regulation of fluid compartments and lymphatic system

Question 1

extracellular

Answer 1

consists of plasma and ISF (outside blood surrounding cells)

Question 2

osmosis decides

Answer 2

intracellular: extracellular volumes

Question 3

What decides ISF: plasma volumes

Answer 3

colloid osmotic pressure ( created by proteins)
Hydrostatic pressure (created by heart)

Question 4

Failure to regulate fluid compartments leads to

Answer 4

oedema

Question 5

Osmosis def

Answer 5

net diffusion of H2O across selectively permeable membrane from high to low water conc

Question 6

Osmoles

Answer 6

total number of particles (solute) in solution

Question 7

1 Osm

Answer 7

1 mole (6.02 x 10^23) of solute particles in 1L

Question 8

ratio of intra to extra particles

Answer 8

intra=extra= 300 mM= 300 mOsm

Question 9

Osmolarity independent of

Answer 9

molecular weight- dependent on number of molecules not size

Question 10

More particles =

Answer 10

higher osmotic pressure

Question 11

osmotic pressure def

Answer 11

pressure required to prevent osmosis

Question 12

extracellular = 300 mOsm/L

Answer 12

isotonic- no change

Question 13

extracellular = 200 mOsm/L

Answer 13

hypotonic- cell swells

Question 14

extracellular = 400 mOsm/L

Answer 14

hypertonic- cell shrinks

Question 15

why can colloid osmotic pressure occur in the capillaries

Answer 15

capillary mem is semi-permeable
Permits diffusion of ions, water, O2, nutrients, and waste
NOT proteins
hence conc of proteins much higher in plasma than ISF

Question 16

what is colloid osmotic pressure

Answer 16

pressure exerted by higher levels of protein in the plasma compared with ISF (6x)
Draws water back into plasma by osmosis

Question 17

hydrostatic pressure

Answer 17

force exerted by blood upon capillary walls
Drives blood from plasma into interstitial space
Pressure drops as blood moves through capillaries
Higher hydrostatic pressure at the beginning than the end

Question 18

NFP

Answer 18

capillary net filtration pressure

determines overall movement across capillary membrane

Question 19

NFP =

Answer 19

(Pc + πif)- (Pif + πc)

Question 20

Pc

Answer 20

capillary hydrostatic pressure

Question 21

Pif

Answer 21

ISF hydrostatic pressure

Question 22

πc

Answer 22

osmotic force due to plasma protein conc

Question 23

πif

Answer 23

osmotic force due to ISF protein conc

Question 24

P and π

Answer 24

P= hydrostatic pressure
π= colloid osmotic pressure

Question 25

At arterial end of the capillary

Answer 25

High NFP in mmHg net outward filtration hydrostatic pressure dominates

Question 26

At venous end

Answer 26

low NFP net inward filtration colloid pressure dominates

Question 27

hydrostatic vs colloidal osmotic

Answer 27

filtration vs absorption

Question 28

How much fluid a day is lost into tissues and what happens to it

Answer 28

8L per day, due to bulk flow | drains into lymphatic system and back into the blood

Question 29

lymphatics essential for

Answer 29

absorption of ISF

Question 30

Lymph system 2 main functions

Answer 30

drains fluid from the tissues and returns it to the cardiovascular system Maintains immune response

Question 31

Drainage (lymph)

Answer 31

excess fluid passes into lymph capillaries, through lymph nodes (detection of infection) before going back into the bloodstream at the neck (largest is thoracic duct that drains into the subclavian vein)

Question 32

How is fluid driven in lymph vessels

Answer 32

valves Action of muscles and breathing Larger vessels surrounded by smooth muscle that contracts spontaneously and driven by pacemaker cells (heart)

Question 33

Immunity (lymph)

Answer 33

Lymph fluid has WBCs Collects antigens Antigens recognised by B cells in lymph nodes leading to activation of immunity B cells proliferate to make antibodies

Question 34

Increased capillary pressure at both ends

Answer 34

leads to oedema and heart failure due to: - excessive kidney retention of H2O - Incr arteriolar resistance - high venous pressure

Question 35

Decr in colloid osmotic pressure

Answer 35

reduction in plasma proteins loss of proteins in urine (kidney failure) loss of protein in denuded skin areas (burns) malnutrition

Question 36

blockage of lymph noded | s

Answer 36

water can't get back into blood- swelling

Question 37

Intracellular oedema

Answer 37

eg friction blister of the skin Depression of metabolic systems of the tissues and lack of nutrition to the cells eg ischaemia: less activity of Na+ pumps leads to accumulation of Na+ in cells, causing osmosis of water into cells, swells