Lower Motor Neuron Pathology

Question 1

What kind of paralysis does lower motor neuron damage produce?

Answer 1

Flaccid paralysis

Question 2

Name 5 problems that lower motor neuron damage can produce

Answer 2

flaccid

paralysis, muscle wasting (atrophy), hypoflexia (e.g., absence of stretch reflex), and fibrillation

Question 3

Name 4 diseases caused by lower motor neuron damage

Answer 3

Amyotrophic lateral sclerosis (ALS), Myasthenia gravis, Polio virus, Spinal muscular atrophy

Question 4

Describe amyotropic lateral sclerosis

Answer 4

motor neurons die, leads to muscle wasting, spreads to cortical motor neurons
-respiratory neurons eventually affected, which leads to death

Question 5

Describe myasthenia gravis

Answer 5

autoimmune disorder where antibodies attack nicotinic receptors-leads to acetylcholine receptor loss, so acetylcholine no longer effective
-treated with acetylcholinesterase inhibitors, like neostigmine, to prolong acetylcholine’s action

Question 6

Describe polio virus

Answer 6

causes paralysis and pain after axonal transport in motor and sensory nerves

Question 7

Describe spinal muscular atrophy

Answer 7

incurable genetic disease caused by a defect in the SMN protein necessary for survival
of motor neurons (SMN = “survival motor neuron protein”)
-widespread cell death of motor neurons and subsequent muscle wasting