11/29

Question 1

Sarcoplasmic Reticulum

Answer 1

Skeletal: triad, T tubule at A/I band junction

Cardiac: diad, T tubules at Z disc and larger than skeletal, anastamosing network near T tubule rather than cisterns like skeletal

Question 2

Smooth Muscle

Answer 2

Thin filaments have tropomyosin, caldesmon and calponin

No troponin associated with tropomyosin

Thick filaments are myosin II that are side polar that maximizes thin and thick filament interaction

Ca-calmodulin Complex binds to Myosoin Light Chain kinase to initiate contraction, phosphorylates two of the regulatory light chains of myosin

Contraction depends on mechanical impulses, electrical depolarization, and chemical stimuli like IP3 or vasopressin