HTHSCI 1H06 Lecture Notes - Lecture 6: Sliding Filament Theory, Intercalated Disc, Skeletal Muscle
10 Feb 2018
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Document Summary
Smooth vs cardiac vs skeletal (morphology, location, function, activation) describe in general terms. Skeletal muscle: msk system, very large, striated, multinucleated, no gap junctions, no auto-rhythmicity, fast contractions, regulated by somatic nervous system, cardiac muscle: In the heart: large, striated, 1-2 nuclei, branched, gap junctions (intercalated disks, auto-rhythmicity, moderate speed, regulated by ans, pacemaker cells and hormones. Smooth muscle: hollow organs, small, no striations, single nucleus, spindle shaped, gap junctions present, auto-rhythmicity, slow contractions, regulated by ans, pacemaker cells, hormones and stretching. Skeletal muscle organization (muscle, fascicle, myocyte - muscle fiber, myofibril, sarcomere, thick. Striation patterns (i vs a band, m vs z line: a band contains the entire myosin fibril, part of actin is in connection with myosin. I band is opposite of the a band, contains only actin, no myosin, and lies between sarcomeres. Structural proteins (z-disk: contractile proteins (myosin & actin, regulatory proteins (troponin, tropomyosin) Factors affecting muscle size (hypertrophy vs atrophy: hypertrophy: enlargement of the muscles.
