4.6 Transfer of Materials between Circulatory Sytem + Cells Flashcards
what is tissue fluid?
extracellular fluid which bathes the cells of most tissues
what two factors are involved in transporting materials?
oncotic pressure - tendency for water to move into capillaries by osmosis
hydrostatic pressure- pressure from heartbeat that is still present as blood enters arterial end of capitally and forces fluid out through capillary walls
when hydrostatic pressure is greater than oncotic pressure, what happens to the fluid?
leaves capillary and tissue fluid forms
when hydrostatic pressure is lower than oncotic pressure, what happens to the fluid?
water moves into capillary and tissue fluid is lost
how does a lymph form?
most tissue fluid is reabsorbed and returned to capillaries
tissue fluid that does not return drains into lymph capillaries and forms a lymph
why do lymph capillaries have valves?
to prevent lymph flowing backward
how is the lymph moved through vessels?
by muscle contraction
