Quiz 6 Understanding Skeletal muscle function and disfunction

The binding of the myosin head to actin active sites requires _____.

Correct!

The uncovering of active sites.

Different levels of muscle cell contraction can be accomplished by stimulating different synapses on a single muscle cell.

You Answered

False

If a substance/molecule is introduced to the neuromuscular junction that initiates the complete release of neurotransmitter from vesicles in the presynaptic terminal. Which of the situations listed below would be expected to occur?

cause a "rigid paralysis"

By increasing the frequency of action potentials on a muscle fiber -

The amount of tension/force development in that cell will increase.

Which of the characteristics listed below is not part of slow, oxidative muscle fibers?

Low resistance to fatigue

Put into the correct sequence the following events involved in skeletal muscle cell contraction.

Voltage-gated sodium channels open, allowing sodium to flow in.

Spreading action potential reaches T tubule activating a DHP receptor

Acetylcholine binds to receptors on muscle cell membrane.

Ligand-gated receptors allow small amounts of sodium into the cell changing membrane potential 10 mV(+).

If enough sodium moves in to the muscle cell, an impulse (action potential) develops.

Ca+ binds to troponin complex initiating the exposure of the active sites on Actin.

Myosin head cleaves ATP to ADP and a phosphate, using the energy to pull the Actin filament.

3,4,1,5,2,6,7

The shortening of a skeletal muscle fiber during contraction involves the shortening of the myosin filaments.

False

Adding more Acetylcholinesterase to the neuromuscular junction could cause ___________.

Flaccid paralysis

Released Ca++ from the sarcoplasmic reticulum (intracellular) will bind/link to which protein molecule associated with skeletal muscle filaments?

Troponin

Tetanus occurs when a muscle fiber is stimulated so rapidly that it is not allowed to relax between stimulations', resulting in a maximal, sustained contraction.

True