KINE 1P90 Lecture 15: KINE 1P90 lecture 15 winter 2016
7 Mar 2016
School
Department
Course
Professor
Document Summary
Lecture 15: blood vessels and circulation part ii. Capillaries are ideally suited to enhance di usion and exchange materials between the blood and the tissues of the body: di using molecules have a short distance to travel between the blood and the surrounding tissues. Capillary walls are thin (a single layer of endothelial cells) The lumen of each capillary is very narrow (red blood cells must squeeze through in single le) Extensive capillary branching (no cell is farther than 0. 01cm from a capillary) The di usion of across capillary walls depends on the permeability of the wall to any given material. This permeability will di er from organ to organ, and may be enhanced (ex. histamine) Pores form between adjacent endothelial cells, and allow the passage of small water- soluble substances. Protein hormones may be moved across the capillary was by vesicular transport. Capillaries branch either directly from an arteriole or from a metarteriole.
