Biology 2581B Study Guide - Quiz Guide: Myofibril, Muscle Spindle, Neuromuscular Junction
3 Jun 2020
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Document Summary
Epimysium, perimysium and endomysium consist mostly of type i collagen. Skeletal muscles are striated, and they are multinucleated. 1 muscle cell = 1 muscle fibre. Skeletal muscles would usually be more tightly packed however this is the artefactual nature of looking at muscle fibres. Light band - shortens but the thick and thin filaments do not shorten. Muscle contraction is achieved by actin filaments sliding over the myosin filaments. T-tubules and sarcoplasmic reticulum are related to each other by the triad. T-tubules are really important for the flow of electricity, while the reticulum is very important for the ca2+ release. They are related to continuous weak contraction, e. g. postural muscles. Rich in myoglobin (accounting for the dark red colour), aerobic. Are related to intense sporadic contraction e. g. biceps, triceps, extraocular muscle. Motor neurones are glutamatergic, and they use ach. One cell has a single neuromuscular junction and the t-tubule allows the excitation to be spread across the cell.
