HK 3100 Study Guide - Midterm Guide: Intrafusal Muscle Fiber, Alpha Motor Neuron, Muscle Spindle

• School: University of Guelph
• Department: Human Kinetics
• Course: HK 3100
• Professor: leahbent

Document Summary

Motor units: morphology (an amn and all the muscle fibres it innervates) Muscle -> muscle fascicle -> muscle fibre -> myofibril -> myofilaments. Ap goes down sarcolemma and down the t tubule, then open calcium voltage gated channels releases calcium from sarcoplasmic reticulum. calcium reconfigures protein (troponin and tropomyosin) and allows myosin to combine and contract. We use ca2+ (released from sarcolemma) to bind to troponin (cause it to change shape), tropomysoin moves away from the myosin binding sites on actin. This allows the mysosin head to bind actin and form a cross bridge. (the myosin head is activated when atp binds it and hydrolyses to adp and pi (the energy from hydrolysis activates myosin head. A signal is sent from the spinal cord. An amn is depolarized causing it to send an ap to the mu. Motor neurons - ( cervical c4-t1 and lumbar t11-l1 enlargements)