Lec 17: Smooth muscle: contraction and mechanics

Question 1

What is smooth muscle contraction driven by?

Answer 1

changes in cytosolic Ca2+.SR:less significant than in skeletal, less structured, no T tubules. Plasma membran Ca2+ channels: voltage and ligand gates Ca2+ channels

Question 2

Describe how smooth muscle contracts

Answer 2

Ca2+ binds to calmodulin in cytosol, Ca2+ calmodulin complex binds to myosin light chain kinase,myosin light chain kinase uses ATP to phosphorylate myosin cross-bridges, phosphorylated cross-bridges bind to actin filaments, cross bridge cycle produces tension and shortening