Made Ridiculously Simple Flashcards
Cluster of neuron cell bodies
gray matter
Myelinated axon pathways
white matter
Which cells provide myelin in the PERIPHERY?
Schwann cells
Which cells myelinate the CNS?
Oligodendrocytes
Which cranial nerve communicates between the brain and thoracic abdominal viscera?
Vagus Nerve (CN X)
corticospinal tract is the main _____ pathway
motor
Where do upper motor neurons (UMNs) cross/dessucate?
medullary pyramids (in the lower medulla)
The upper motor neurons (UMNs) synapse on what part of the spinal cord?
Anterior horn
The anterior horn cells and their axonal projections in peripheral nerves
Lower motor neurons (LMNs)
Where do lower motor neurons (LMNs) synapse?
on the muscles
The right motor cortex controls which part of the body?
the left side!
*bc UMNs cross in the medulla, so the R motor cortex controls the L side of the body (and vice versa)
Injury of anterior horn cells and/or peripheral nerves
Lower motor neuron (LMN) lesion
Injury to internal capsule, brainstem or spinal cord
Upper motor neuron (UMN) lesion
Spastic paralysis, tonic contractions
Increased/hyperactive reflexes
Babinski’s sign (big toe goes up rather than curling down)
Clonus (repetitive rhythmic contraction of a muscle when it is stretched)
Upper motor neuron lesion (UMN)
Reflex of big toe going up rather than curling down
**seen with UPPER MOTOR NEURON lesion
Babinski’s reflex
