The cytoskeleton provides support in a cell. It is a network of protein fibers supporting cell shape and anchoring organelles within the cell. The three main structural components of the cytoskeleton are microtubules (formed by tubulins) , microfilaments (formed be actins) and intermediate filaments.
epinephrine binds to beta 2 receptors to relax airway smooth muscle and relaxes larger arteries to supply more blood to metabolizing tissues What is theophylline? an inhibitor of phosphodiesterase so it will potentiate the effect of epinephrine and inhibit cAMP breakdown to relax smooth muscle
Note: There are more than two types of epinephrine receptors on smooth muscle cells, so epinephrine may affect smooth muscle in other tissues in other ways. (There are subtypes of alpha and subtypes of beta.) * Details of how PLC generates IP3 are on handout 12A. We will go over this later.