Functional and Dysfunctional Neuroanatomy

Lecture 18 and 19

What part of the neuro exam yields our differential list?

neurolocalization

List the functional divisions of the brain.

cerebrum

diencephalon (thalamus, hypothalamus)

brainstem (midbrain, pons, medulla)

cerebellum

vestibular system

UMN or LMN:

• located entirely within CNS

• descend from brain to every segment of spinal cord

• initiate voluntary movement

• both excitatory and inhibitory influence on other neuron to maintain muscle tone and arc reflexes

UMN (upper motor neuron)

UMN or LMN:

• located in CNS and PNS

• involved with reflex arc (sensory and motor)

• carry out motor function

LMN (lower motor neuron)

The upper motor neuron system originates in what two parts of the brain?

pyramidal system (motor cortex) —> corticospinal tracts

extrapyramidal system (basal nuclei) —> rubrospinal tracts

What part of the UMN system is thought to play the biggest role in gait?

red nucleus of the midbrain