Smooth Muscle

Smooth Muscle

1. classified

   • Circular Layers
     • Blood vessels and Bronchiolos
   • Longitudinal and circular
   • Peristaltic Waves

2. Muscle cells

   • No sarcomere
     • More actin and less myosin
       • thin filaments
         • Ca2 + calmodulin
           • Activates the MLCK chain
             • Enzyme that catalyzes the phosphorylation
               • phosphorylation : Key for contraction
   • Lack of Troponin

3. Relaxation

   • Ca2 channels closes
     • Glamodulina dissociates from MLCK
       • Also
         • Power punch is inhibited by bridge

4. Contraction

   • Ca2 high concentration
     • sustained contraction
       • high despolarization+more Ca2
         • highest concentration

5. Two categories

   • Only Unit and Multiple Unit
     • Only UnIt: Only some cells receive innervation
       • Multiple unit: requires nerve stimulation