Spinal Reflex Arc

Question 1

What is a Spinal reflex arc?

Answer 1

A reflex that is mediated at the SC level.

Question 2

Is there cortical involvement in a spinal reflex?

Answer 2

No cortical involvement - no conscious decision making.

Question 3

What do spinal reflexes allow?

Answer 3

Sensory information to be processed and acted upon quickly, without cortical processing.

Question 4

What is the pathway of a spinal reflex arc?

Answer 4

1. A sensory receptor (PNS) sends a message along an ascending sensory spinal nerve.
2. The sensory spinal nerve travels to the dorsal horn where it synapses on an interneuron.
3. The interneuron synapses on a motor cell body located in the ventral horn.
4. The motor cell body in the ventral horn relays the message to a motor spinal nerve in the PNS.
5. The message travels to a skeletal muscle group for action in response to the initial sensory message.