A drug that inactivates acetylcholinesterase A.inhibits the release of ACh from

the number of fibres that are contracting. Muscles that move the fingers. please rate, thanks

ID: 3510736 • Letter: A

Question

A drug that inactivates acetylcholinesterase

A.inhibits the release of ACh from presynaptic endings.

B.inhibits the attachment of ACh to its receptor protein.

C.increases the ability of ACh to stimulate muscle contraction.

D.does all of these.

Postsynaptic inhibition is produced by

A.depolarization of the postsynaptic membrane.

B.hyperpolarization of the postsynaptic membrane.

C.axoaxonic synapses.

D.long-term potentiation.

The summation of EPSPs from numerous presynaptic nerve fibers converging onto one postsynaptic neuron is called

A.spatial summation.

B.long-term potentiation.

C.temporal summation.

D.synaptic plasticity

A graded whole muscle contraction is produced in vivo primarily by variations in

A.the strength of the fiber's contraction.

B.the number of fibers that are contracting.

C.both of these.

D.neither of these.

Which of these muscles have motor units with the highest innervation ratio?

A.Leg muscles

B.Arm muscles

C.Muscles that move the fingers

D.Muscles of the trunk

Electrical excitation of a muscle fiber most directly causes

A.movement of tropomyosin.

B.attachment of the cross bridges to action.

C.release of Ca2+ from the sarcoplasmic reticulum.

D.splitting of ATP.

the number of fibres that are contracting.

Muscles that move the fingers.

please rate, thanks

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