Question

1.)

Neurotransmitters released from a presynaptic neuron, which bind to receptors of a       postsynaptic neuron, results in depolarization in the following way:

a.)voltage-gated channels opening, Na+ in

b.) ligand-gated channels opening, Na+ in

c.)simple diffusion

d.) leakage

The sciatic nerve:

a.) originates in the lumbar plexus

b.) branches to become two separate peripheral nerves

c.) is part of the CNS

d.) is only sensory

The somatic reflex arc has the following components:

a.) somatic receptors in the viscera

b.) afferent fibers to dorsal horn to the spinal cord

c.) efferent fibers to the viscera

d.) a & c above

The muscle spindle is:

a.) a sensory organ for proprioception

b.) composed of extrafusal fibers

c.) monitors the length of tendons

d.) all the above

A polysynaptic and ipsilateral reflex arc means:

a.) one synapse, same side

b.) one synapse, opposite side

c.) two/more synapses, same side

d.) two/more synapses, opposite side

Thanks!!!!

Answer 1

1. ANSWER: A. Voltage gated channels opening sodium in.

Reason: Depolarisation happens by opening of voltage gated sodium channels which lets the sodium ions in.

2. ANSWER: b. Branches to become two peripheral nerve.

Reason: sciatic nerve branches at its terminal end to form two seperate peripheral nerves.

3. ANSWER: b. Afferent fibres to the dorsal horn of thespinal cord.

Reason: Receptors are present on the muscles tendon and not on the viscera.

4. ANSWER: c. Monitors the length of the tendon.

Reason: muscle spindle are stretch receptors whcih monitors the length of the muscle fibres.

5. ANSWER: two/ more synapses, same side.

Reason: polaysynaptic means many synapses and ipsilateral means same side.