Format

Send to

Choose Destination
Adv Physiol Educ. 2003 Dec;27(1-4):201-6.

Smooth muscle contraction and relaxation.

Author information

1
Department of Physiology, Medical College of Georgia, Augusta, Georgia 30912, USA. cwebb@mcg.edu

Abstract

This brief review serves as a refresher on smooth muscle physiology for those educators who teach in medical and graduate courses of physiology. Additionally, those professionals who are in need of an update on smooth muscle physiology may find this review to be useful. Smooth muscle lacks the striations characteristic of cardiac and skeletal muscle. Layers of smooth muscle cells line the walls of various organs and tubes in the body, and the contractile function of smooth muscle is not under voluntary control. Contractile activity in smooth muscle is initiated by a Ca(2+)-calmodulin interaction to stimulate phosphorylation of the light chain of myosin. Ca(2+) sensitization of the contractile proteins is signaled by the RhoA/Rho kinase pathway to inhibit the dephosphorylation of the light chain by myosin phosphatase, thereby maintaining force generation. Removal of Ca(2+) from the cytosol and stimulation of myosin phosphatase initiate the process of smooth muscle relaxation.

PMID:
14627618
DOI:
10.1152/advan.00025.2003
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center