Neuroanatomy: Spinal Cord Reflexes

Question 1

Define a reflex

Answer 1

A type of local processing occurring in the spinal cord. Influenced by the brain but does not require the brain’s permission.

Question 2

What are the components of a reflex?

Answer 2

A receptor (in skin, musccle, joint, or viscera), afferent (sensory) fiber (process of a dorsal root ganglia neuron), Interneuron in spinal cord (distinguishes a polysynaptic from a monosynaptic reflex), Efferent (motor) fiber (axon of motor neuron in the ventral horn), effector (muscle (striated or smooth) or gland)

Question 3

What is the difference between a mono and polysynaptic reflex?

Answer 3

Polysynaptic - pain reflex, flexor reflex, uses receptor peripheral processors to signal muscle to contract
Monosynaptic - typically a tendon reflex, muscle spindle detects muscle length and sends out different types of signals to a motor neuron to muscle

Question 4

How is your brain involved in reflexes?

Answer 4

it influences the reflexes and can modify the reflexes