Descending (UMN) Tracts Flashcards
Signs of damage?
spastic paresis/paralysis
normo-hypertonia
normo-hyperreflexia
disuse atrophy
Where in the spinal cord?
lateral and ventral funicului
Lateral corticospinal tract
Pyramidal system
Cell bodies in cortex of frontal lobe
100% crossover in medulla
Excitatory to LMNs of flexors on opposite side
Unimportant in domestic animals on flat surface
Rubrospinal tract
Extrapyramidal system
Cell bodies in red nucleus of midbrain
Excitatory to LMNs of flexors on opposite side
Initiate and regulate voluntary mvmt
Tectospinal tract
Extrapyramidal system
Cell bodies in rostral colliculus of tectum of midbrain
Excitatory to LMNs of flexors in neck on opposite side
Sight avoidance reflex and sight tracking
Tectotegmental tract
Extrapyramidal system
Cell bodies in tectum (rostral colliculus) and tegmentum of midbrain
Sympathetic control of eye and pupillary dilation
Control GVE LMNs in intermediolateral grey horn T1-T4
Damage –> Horner’s Syndrome
Horner’s Syndrome
4 clinical signs
lack of sympathetic innervation to eye
- constricted pupil / miosis
- enophthalmus (eye sunken into socket)
- 3rd eyelid protrusion - bc of enophthalmus
- ptosis - bc of enophthalmus
Pontine reticulospinal tract
Extrapyramidal system
Cell bodies in tegmentum of pons
Excitatory to LMNs of extensors
Controls posture and locomotion
Medullary reticulospinal tract
Extrapyramidal system
Cell bodies in tegmentum of medulla
Inhibitory to LMNs of extensors
Regulates posture and locomotion, GVE LMNs, and muscle spindles
Lateral vestibulospinal tract
Extrapyramidal system
Cell bodies in vestibular nuclei of vestibular trigone in medulla
Excitatory to LMNS of extensors on same side,
Inhibitory to LMNs of flexors on same side,
Inhibitory to LMNs of extensors on opposite side
Adjusts posture in relation to head mvmts,
Regulates balance and equilibrium,
Controls normal standing posture
Medial longitudinal fasciculus
Extrapyramidal system
Cell bodies in vestibular nuclei of vestibular trigone of medulla
Controls LMNs of CNs III, IV, VI
Adjusts posture in relation to head mvmts