Physiology 2130 Lecture 5: Module 5 - Muscles
24 Jan 2016
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Document Summary
Muscles biological machines that use chemical energy from breakdown/metabolism of food to perform useful work. Three kinds of muscle cells: skeletal (primarily for voluntary motion), smooth (within the walls of blood vessels, airways, ducts, urinary bladder, uterus, digestive tract), cardiac (in the heart) The body contains >600 different muscles that perform 2 principal functions: movement 2) heat production and 3) body support and posture. Whole muscles are made up of bundles of fasciculi. Each fascicle is made up of groups of muscles cells or fibers. Each muscle cell contains many bundles of myofibrils. Each myofibril contains thin and thick myofilaments. Thin myofilaments contain mostly the protein actin along with troponin and tropomyosin. The interaction of thin and thick myofilaments results in muscle contraction (thick and thin sliding past one another) Whole muscles fasciculi fascicle muscle cells myofibrils myofilaments thin/thick thin: actin, troponin, tropomyosin thick: myosin thin & thick=muscle contraction.
