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Muscles - Anatomy & Physiology (view source)
Revision as of 14:22, 21 July 2008
, 14:22, 21 July 2008→Skeletal Muscle
***High '''glycolytic''' activity
***High '''glycolytic''' activity
***Function - exercise, bursts of activity
***Function - exercise, bursts of activity
*Muscle activation is initiated by a nervous impulse crossing the Neuromuscular Junction
**The neurotransmitter, Acetylcholine (Ach), binds receptors in the muscle fiber to open Na+ channels
**This causes a wave of depolarization along the sarcoplasmic membrane, further opening voltage-gated Na+ channels, which propagates the signal along the sarcolemma
**Depolarization of the sarcoplasmic reticulum causes Calcium to be released, which activates muscle contraction
***Muscle contraction occurs when (thin) Actin filaments slide past (thick) Myosin filaments
***Myosin heads bind Actin subunits, forming cross-bridges, hydrolyzing ATP and providing energy for contraction
***Myosin heads undergo power stroke, displacing Actin and releasing ADP and Pi
***Calcium regulates muscle contraction by binding troponin-C, which is attached to the thin filament
***This causes inhibition of the steric block keeping Actin and Myosin from interacting
**Increased Calcium causes a negative feedback inhibition of Ca release, and it is pumped back into the sarcoplasmic reticulum by the Ca/ATPase pump
==Tendon==
==Tendon==