Muscular Action Potential & Cross Bridging

What ends the stimulation of the muscle fiber at the neuromuscular junction?

acetylcholine

What is the final “trigger” for muscle contraction?

Calcium

Generally speaking, what leads to the action potential that allows for contraction to occur along the entirety of the muscle fiber?

the opening of specific channels allowing for sodium in and potassium out

What constitutes cross bridge formation?

the linking of myosin heads to actin

What must rush into a muscle cell to promote it's depolarization?

Sodium ions

Which of the following components blocks myosin binding sites on actin?

Tropomyosin

When ___ binds to troponin it causes tropomyosin to uncover the ___ binding sites on actin.

Calcium, myosin

Order the steps of the cross bridge cycle

1. Cross bridge formation

2. Power stroke

3. Cross bridge detachment

4. Reactivation of the myosin head

Which of the following structures allows for the distribution of calcium/needed components to every myofibril inside a muscle fiber?

T-tubules

According to the sliding filament theory, how does muscle contraction occur?

myosin heads form cross bridges and pull thin filaments, causing them to slide

What is found in the synaptic cleft that prevents continued contraction of the muscle fiber?

Acetylcholinesteease

Which of the following components causes the myosin head to detach from actin?

ATP