Anatomy and Cell Biology 3309 Lecture Notes - Skeletal Muscle, Myosin Head, Dict
12 Jul 2019
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Document Summary
Skeletal muscle attached to bones: contraction of the contractile units allows us to move our bodies, has to cross a joint, to get movement. 1 muscle fiber/myofiber = 1 skeletal muscle cell: made up of tons of myofibrils. Perimysium: lct enclosing each fascicle more well developed lct than endomysium: difference: Perineurium formed blood-nerve-barrier, so blood vessels were on the outside. Perimysium actually houses the blood vessels & nerves. Epimysium: dict enclosing the whole muscle: muscle is attached to bone, by a tendon, tendons (drct) are formed by all three layers coming together at edge of the muscle. In cross section, stippled appearance is due to the arrangement of the myofibrils. Skeletal muscle fiber ultrastructure: myofibril: chain of sarcomeres. Lots of mitochondria bc muscle contraction is very energy dependent. Striated appearance due to dark a band and light i band, that alternate: bands are due to overlap or lack of overlap of contractile proteins, w/in the contractile unit.
