The Nervous System

Question 1

If a neurotransmitter causes the entry of chloride into the postsynaptic cell is the neurotransmitter excitatory or inhibitory?

Answer 1

Chloride ions are negatively charged. The entry of chloride ions into the cell will make the postsynaptic potential more negative or hyperpolarized so the neurotransmitter is inhibitory.

Question 2

If an inhibitor of acetylcholinesterase is added to a neuromuscular junction then the postsynaptic membrane will:

A) be depolarized by potentials more frequently
B) be depolarize longer with each action potential C: be resistant to depolarization
D) spontaneously depolarize

Answer 2

B.

If acetylcholinesterase is inhibited acetylcholine will remain in the synaptic cleft longer and acetylcholine gated sodium channels will remain open longer with each action potential that reaches the synapse. It is sodium channels are open longer the depolarization of synaptic membrane will last longer.

Question 3

What portion of the CNS would you expect to require input from proprioceptors?

Answer 3

The cerebellum, which is responsible for motor coordination.