A)is responding to a nerve control that inhibits heartbeat.
B)is dying since nerves can only stimulate muscle action.
C)is unaffected by the nerve but responding to some unknown chemical factor.
D)is normal as all nerve stimulation results in decreased muscle activity.
E)None of the choices is correct.

A)receptor,efferent nerve,nerve center,afferent nerve,effector.
B)effector,afferent nerve,nerve center,efferent nerve,receptor.
C)receptor,afferent nerve,nerve center,efferent nerve,effector.
D)effector,efferent nerve,nerve center,afferent nerve,receptor.
E)All of the choices are correct.

A)always involves acetylcholine.
B)always involves some neurotransmitter that stimulates the next neuron.
C)is a point at which ionic currents flow directly across a narrow gap junction.
D)involves either an inhibitory or stimulating neurotransmitter chemical.
E)None of the choices is correct.