smoothmuscle

smoothmuscle - Lecture Outline March 3, 2008 Smooth Muscle...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture Outline March 3, 2008 Smooth Muscle Functions 1. tonic contraction maintains organ dimensions against imposed load 2. force development propels the luminal contents of the organ mixing varies the diamet er of a tube to regulate the flow of its contents Structural anatomy one nucleus; can undergo mitosis and hyperplasia lacks sarcomeres dense bodies are equivalent of z lines, anchor actin no t-tubules SR not as extensive Contraction myosin-linked regulation 1. cytosolic Ca 2+  binds with calmodulin (Ca 2+ •CM) 2.  Ca 2+ •CM activates myosin kinase which phosphorylates myosin 3.  P i  activates myosin and enables myosin to bind with actin 4. power and recovery strokes same as skeletal 5. termination requires phosphatase enzymes to remove phosphate from myosin--deactivates myosin Biology 141: Physiology 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lecture Outline In general, contraction is associated with increased intracellular Ca 2+  concentrations and/or decreased cAMP activity
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

smoothmuscle - Lecture Outline March 3, 2008 Smooth Muscle...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online