Spinal reflex, spinal cord injuries

Question 1

Spinal Reflex Arcs

Answer 1

Neural pathways that produce a rapid, predictable,
involuntary somatic or autonomic reflex response to a stimulus
1. receptor 2. sensory neuron 3. integration centre 4. motor neuron 5. effector

Question 2

Somatic Reflexes

Answer 2

are mediated by reflex integration centres within the spinal cord
- stimulate skeletal muscle contractions
- involve lower motor
neurons (LMN)
- conduct motor output
from the spinal cord
to a skeletal muscle
- can be modified by the primary motor cortex

Question 3

Spinal Cord Injuries

Answer 3

Result in sensory and/or motor losses at or below the level of the injury
- damage to the posterior gray horns or ascending spinal cord tracts = loss of sensation
- damage to the anterior gray horns or corticospinal tracts = spastic or flaccid paralysis

Question 4

spastic paralysis

Answer 4

Damage to upper motor neurons
- loss of voluntary movement
- reflex activity intact, but
abnormal

Question 5

flaccid paralysis

Answer 5

Damage to lower motor neurons
- loss of voluntary movement & reflex activity