Physiology 2130 Lecture Notes - Lecture 5: Sliding Filament Theory, Endoplasmic Reticulum, Neuromuscular Junction

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: Anita Woods

Document Summary

Whole muscle fascicles (muscle fibers) myofibrils myofilaments contain a myosin binding site sites until calcium arrives during contraction. (thin and thick) The muscle cells/ fibers are multinucleated with lots of mitochondria because we need atp to have contraction. Skeletal muscle is striated and this comes from the thick and thin myofilaments. The number of muscle cells in the whole muscle depends on size of the whole muscle (1mm-12cm). Cell membrane of the muscle cell is called the sarcolemma. Transverse tubules are continuations of the sarcolemma and wrap around each myofibril; they allow the ap to travel the surface of the sarcolemma down inside the muscle cell where the contractile proteins are. Sarcoplasmic reticulum warps around myofibrils; it is a hallow structure storing calcium. The portion of the sr directly around the t tubules are called lateral sacs, here the calcium is released for contraction. Thin myofilaments (actin) are made of three contractile proteins: G-actin two stranded alpha-helical chain; they each.