AH 2330 Lecture Notes - Lecture 26: Endothelium, Hypothalamus, Theca Interna
Document Summary
Structure: very different than that of arterioles + veins because their jobs is to i. walls have to be permeable to blood and things found in blood so that transport and. Transport blood capillaries designed to exchange ii. capillaries are very small actually just larger than the diameter of the rbc"s since so narrow rbc"s have to line up and travel through the capillary in a single file. Cells )ncreases surface area for exchange to happen i. fenestrated: more spaces btw them allow some things to move paracellularly make up the tunica interna. continuous: very few gaps in between them, very high number of tight junction proteins. Important for getting hormones out of the brain and into the general circulation. Capillary exchange: main function: continuous capillaries: ions/ small polar molecules may pass, nutrients/oxygen/metabolic products transported by i. most important transport mechanisms for all capillaries: diffusion. process of moving nutrients across a capillary wall and into the tissues or vice versa diffusion .
