Lecture 1: Intro to the Nervous System Flashcards
Where are the somas of lower motor neurons?
Brainstem or spinal cord
What types of muscles need to be innervated by many motor units?
Small muscles that need rapid and precise control
What are the lower motor neuron signs?
Atrophy, fasciculations, hypotonia, hyporeflexia
Myopathy
Symmetric bilateral proximal limb weakness.
Proximal muscles lift more weight; will be noticed there first.
Polyneuropathy
Symmetric weakness Lower motor neuron signs Somatosensory abnormalities Distal parts of longest nerves affected most Muscle stretch reflex diminished Stocking and glove pattern
Mononeuropathy
Dysfunction of a single nerve.
Common: median nerve- carpal tunnel syndrome
Radiculopathy
Dysfunction of spinal nerve roots
Shooting pain
Somatosensory and LMN abnormalities
Common: L5
What are the corticobulbar tracts?
Upper motor neurons descend from the cerebral hemispheres to LMNs in the brainstem.
Corticalspinal Tracts
UMNs descending from the cerebral hemispheres to LMNs in the spinal cord
Upper Motor Neuron Signs
Hyperreflexia
Hypertonia
Abnormal extensor plantar response (Babinski)
Myelopathy
Dysfunction of spinal cord
UMN signs below lesion
LMN signs at level of lesion
Cerebellar Syndrome
Incoordinated movements
Slurred speech
Middle cerebellum: Walking trouble
Lateral cerebellum: Ipsilateral limb trouble
Sulci
Small grooves in the cerebrum
Most common excitatory neurotransmitter in brain
Glutamate
Most common inhibitory neurotransmitters in brain
GABA and glycine
