Blood & Capillary Overview (Fig 23.13; p. 477)

http://facstaff.gpc.edu/~jaliff/anablves.htmhttp://focus.aps.org/story/v20/st21

Blood• Human Circ. System has 4-6 L.

• Cellular Elements represent 45% of total blood volume.

–RBCs & WBCs

–Plasma (Straw colored liquid)

–Platelets (part of bone marrow cytoplasm)

Plasma• Makes up over 1/2 of blood volume.

• 90% is H2O

• 10% is inorganic salts (ions, proteins, etc)

–Ions = osmotic balance / pH balance

–Proteins =

•Blood clotting (fibrinogen)

• Immunity (immunoglobulins)

Capillaries

• Thin enough for Transport of Substances between Blood and Interstitial Fluid.

• Composed of epithelial cells.

Transport of Substances(Fig. 23.12B; p. 476)

• O2 & CO2 = Diffusion

• Lgr. Molecules = Vesicles/ Endocytosis /Exocytosis

• H2O & Solutes = “Leaky clefts”

• Proteins = Too Big to pass through

Forces Transport of Substances

• Blood Pressure - active force pushing fluid outward.

• Osmotic Pressure - active force pulling fluid inward

(* [solute] in blood ).