PHY3111 Study Guide - Myostatin, Muscle Hypertrophy, Skeletal Muscle
Document Summary
Splanchnic -> cardiac muscle (heart) and smooth muscle (blood vessel and gut muscle) Myostatin - a protein that regulates development+growth of skeletal muscle. Loss of myostatin = myostatin-related muscle hypertrophy (high skeletal muscle levels) = more muscly. Duchenne muscular dystrophy - absence of dystrophin = muscle fibres more susceptible to damaged when physically stressed. Generate less tension than the other muscle types. Eg. back muscles - a long, slow contraction is required to maintain erect posture. A high percentage of these fibres are found in muscles of high-endurance athletes, eg. marathon runners. Larger than type i / slow twitch fibres. Two types: type ii-a = fast oxidative, and type ii-b = fast glycolytic. Smooth muscle develops from the differentiation of individual mesodermal cells. They also may arise from myofibroblasts and myoepithelial cells. Smooth muscle retains the ability to regenerate and multiply: multiunit, visceral. They are often innervated by one nerve terminal. When stretched beyond a certain limit, they contract simultaneously.
