BIO304H5 Lecture : #22 Muscle 2
Document Summary
Some muscle fibers can generate their own action potentials. Coupling experiment #2. vary the concentration of potassium thus altering membrane potential. The amount of force generated by the muscle increases as the membrane potential becomes more positive. Stimulate near t-tubules and you see contraction of adjoining sarcomeres. Stimualte between to t-tubules and you see no contraction. Plasma membrane that surrounds a certain part of the sarcomere with extensions called transverese tubules. Creates a tube down insde the muscle cell. Membrane depolarization or aps carried deep into the muscle by t-tubles. Depolarization from the motor nerve leads to +ve neurotranmistted entering msucle cell and are then carried by the t-tubules though out all muscle. Initially in the myoplasm (intracellular, where all the msucle structures are) has a negative potential. Striated muscles with an axon (difference in drosophila is they receive information from multiple neurons. The motor unit recrutied thrid (last ) is the one with the most motor neurons.
