BIOL 2160 Study Guide - Final Guide: Neuromuscular Junction, Endoplasmic Reticulum, Myocyte
1 May 2018
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Chapter 11
Muscle Physiology
Types of Muscle
• Skeletal Muscle
• Voluntary
• Cardiac Muscle
• ^ both striated
• Smooth Muscle
Skeletal Muscle Structure
Muscle fiber is a cell. A muscle cell is a muscle fiber. Muscle cells are multinucleated.
A membrane defines a cell. This is all a single membrane, so it’s a single cell.
Skeletal Muscle Structure
• One muscle fiber = one cell
• Proteins make a cell larger
• Someone who works out a lot drinks protein shake to make muscles
bigger
• One muscle fiber has many nuclei—multinucleated
• Muscle fibers contain myofibrils – rod-like elements that contain contractile
machinery
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Skeletal Muscle Fiber Structure
• Acetyl choline gets released from the motor neuron and binds to nicotinic
receptors on muscle fiber
• The synapse is called Neuromuscular junction
• Light blue- sarcoplasmic reticulum
o Same thing as ER but in a muscle cell
o Full of calcium
• All muscle contraction requires two things:
o Calcium
o Atp
• T tubules
o Membrane deep into the tissue
o Penetrate deep into the muscle cell to allow all microfibers to contract
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find more resources at oneclass.com
• Dark orange part: motor end plate
o Part of the muscle cell **
o It is different because the motor end plate is where all acetyl choline
receptors are found
Neuromuscular Junction
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Types of muscle: skeletal muscle, voluntary, cardiac muscle, ^ both (cid:498)striated(cid:499, smooth muscle. Skeletal muscle structure bigger: one muscle fiber = one cell. Neuromuscular junction: end plate potential (epp, action potential on the muscle cell, when the muscle cell has received the signal to make an ap and contract. Sarcomere components: allows contraction to occur, sarcomere, thick, myosin, thin, actin, z line is the boundary of sarcomere, when relaxed, myosin is not touching actin. Sarcomere components myosin: myosin, actin binding site, this is where myosin makes contact with actin, atpase site, where it physically breaks down atp. Steps in muscle contraction (excitation-contraction coupling: motor neuron ap, end plate potential (excitation, increase in muscle cell calcium levels, troponin and tropomyosin conformational changes, crossbridge cycling sliding filaments (contraction) Muscle contraction epps: ach is released and binds to the motor end plate, action potential propagates down the t tubules.
