EQN 3050 Lecture Notes - Lecture 3: Myostatin, Anaerobic Respiration, Skeletal Muscle

• School: University of Guelph
• Department: Equine
• Course: EQN 3050
• Professor: Wendy Pearson

Document Summary

Muscle fibre types (~different types w. in skeletal muscle) Classified according to their contractile properties speed of contraction/relaxation. Regulated by myostatin gene inhibits muscle growth and proliferation. Depends on type of myosin and myosin atpase present. Fast fibres rely primarily on anaerobic pathways (~rely on less o, more powerful contractions) ~ distribution of these types of muscle fibers does not depend on genetics but relies on a lot of other things. Type 1 (slow twitch) ie. slow oxidative endurance. ~ not very powerful contraction but they can last a long time. ~ stain very red bc oxidative metabolism occurs in the mitochondria & they have high amounts of mitochondria. ~ occur on ongoing basis, difficult to fatigue. Ie. small motor unit ~ not just muscle but also nerve supplies that muscle. Precise but less powerful contractions ~ allows small but precise movements, not possible w. more powerful muscle fibers. High myosin atpase activity ~ bc rely primarily on oxidative metabolism.