4.6

Answer 1

junction bw single cells making capillary is not very tight so fluid + some molecules can be pushed out to make tissue fluid
1. at aerial end - HP>OP so fluid forced out - inc O2, glucose, WBCs, but prevents RBCs + large proteins
2. at venous end - HP< OP as no P from heartbeat, lower vol in capillary so water diffuses back in via osmosis

Question 2

what 2 factors affect formation of tissue fluid

Answer 2

• oncotic pressure = constant, plasma proteins + RBCs exert an osmotic effect - gives blood relatively constant +low water potential of -3.2kpa
• hydrostatic pressure = from residual heartbeat

Question 3

what happens to tissue fluid thats not reabsorbed

Answer 3

• drains into lymph capillaries - water - less o2 lots of fatty acids

Question 4

how does lymph fluid move around body

Answer 4

in 1 way, have valves move thru contraction of muscles