BIOL 2420 Lecture Notes - Lecture 8: Oncotic Pressure, Vascular Permeability, Starling Equation

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2420
• Professor: W.G.Anderson

Document Summary

Smallest, thinnest and most numerous blood vessels in body. 5 to 10 um in diameter, thus huge surface area (~600 m2) for exchange. Wall thickness is less than one micron (1um) Contain ~ 5% of total circulating blood volume at rest. Composed of a single layer of endothelial cells (a) encased by a thin glycoprotein/collagen matrix (basement membrane) (o2 & co2 (b), plus fatty acids, steroid hormones, anaesthetics) Pericytes sit on top of capillaries and monitor isf exchange. Cells have smaller water- lled intracellular channels (c) with narrow intracellular pores (d) between adjacent cells: I) exchange sites for small water- soluble substances. H20, na+, k+, glucose, amino acids (e) Plasma proteins (ex. albumin) remain in capillary(f) through colloid or oncotic pressure - large proteins that are stuck inside. Loose tting cells with large intracellular spaces. D in rbc gure would be much bigger if it was of this type of capillary.