Channels
This is a type of channel that when a protein is bound to it it will open. Provide the example of this in the NMJ.
What is ligand or chemically gated. Na+ ligand gated channels
The first step of a muscle contraction is?
The AP travels along the neuron
This type of muscle tissue has a different micro anatomy compared to the others?
Smooth muscle tissue
If the VG NA+ channels in a muscle fiber are blocked, what happens to the action potential?
the AP is not generated
What channels open after the depolarization stage occurs in a muscle cell?
K+ VG channels
How is ACh released from the axon terminals?
released from vesicles via exocytosis
What is the name of the complex protein structure that is contained in the myofibrils?
sarcomeres
If the Ca2+ pump works too slowly, how is muscle movement affected?
slower relaxation or poor control of movement
What is the channel that is responsible for the re-uptake of Ca2+ into the SR during the period of muscle relaxation?
Ca2+ pump
What is the purpose of the t-tubules in the NMJ?
allows the depolarization charge to reach deeper within the cells and reach all the myofibrils.
What is the order of fiber recruitment in skeletal muscles?
slow oxidative, fast oxidative, fast glycolytic
Too much calcium leaks from the SR into the cytoplasm? What do you expect to occur?
Continuous or involuntary contraction
The Na+/K+ pump requires oxygen to result in what amount of Na+ and K+ where in relation to the cell? (Hint: where do Na+ and K+ end up, and how many?)
3 Na+ outside and 2 K+ inside
Typically the inside of a muscle fiber has a ______ charge and the outside has _______ charge. When the EPP is generated, what is the new charge of the inside and outside of the cell?
Negative charge inside and positive outside. EPP makes it so it is + inside and - outside.
fast glycolytic fibers
If there is no ACh enzyme present in the synaptic cleft what do you expect to occur?
continuous muscle contraction
Leakage gated channels allow K+ to flow in and out of the cell generating a membrane potential that is unique to muscle cells. When K+ flows out of a muscle cell, what drives that? When K+ flows back into the muscle cell, what drives that?
1st K+ flows out due to concentration (diffuses out), then K+ flows back in because it is attracted to the slightly negative charge
Name the different channels that are present and necessary for muscle contraction to occur until relaxation? (Hint... I thought of 6 I think that is all of them)
Na+/K+ pump
K+ leakage channels
Ligand gated Na+ ion channel
VG Na+
VG K+
Ca2+ pump
What is the reasoning behind why there are not many mitochondria in fast glycolytic fibers?
The generation of ATP for glycolysis occurs in the cytoplasm and not in the mitochondria.
If the neuron releases too little ACh what is the clinical sign that will probably present?
muscle weakness or paralysis.