11 - Motor Cortex and Motor Pathways Flashcards
what is the function of the lateral corticospinal tract pathway?
motor functions
what is the function of the posterior column pathway?
sensory (vibration, joint position, fine touch)
what is the function of the anterolateral pathway?
sensory (pain, temp, crude touch)
major relay for sensory information ascending upwards?
thalamus
what does the anterior view of the spinal cord look like?
butterfly shaped central gray matter surrounded by ascending and descending white matter columns
in the spinal cord, which horn is used for sensory processing?
dorsal horn
in the spinal cord, which horn is used for motor neurons?
ventral horn
what does the intermediate horn of the spinal cord contain?
Intermediate zone contains interneurons & specialized nuclei
what is Rexed’s Laminae?
numbering system from dorsal to anterior, becoming more nuclei
where is the white matter the thickest?
cervical levels, most ascending fibers have already entered the cord, and most descending fibers have not yet terminated on their targets
which cord is mostly gray matter?
the sacral cord
where are the enlargements found along the spine?
cervical and lumbosacral areas and these give rise to the nerve plexi for the arms and legs
what is the blood supply to the spinal cord?
vertebral arteries and spinal radicular arteries
what do the anterior and posterior spinal arteries form?
spinal arterial plexus
how much of the anterior spinal artery supplies the spine?
2/3 of the cord, including the anterior horns & anterior and lateral white mater columns; only one of these
how much of the posterior spinal artery supplies the spine?
(either from the vertebral artery or from the posterior inferior cerebellar arteries) supply the posterior columns and part of the posterior horns; two of these
how many segmental arterial branches arise from the aorta? how many of these reach the spinal cord and as what?
31; 6-10 of these reach the spinal cord as radicular arteries
what is the major blood supply of the lumbar and sacral cord?
Great radicular artery of Adamkiewicz
this is also known as the vulnerable zone of relatively decreased perfusion?
Mid-thorasic region (~ T4-T8)
venous return from the spinal cord drain where?
Plexus of veins drain initially into the epidural space
Epidural veins “Batson’s plexus” do not contain valves: as a result ↑↑ intra-abdominal pressure can cause reflux of pelvic infections, or metastasis of tumor cells
where do all motor signals originate from?
cerebral cortex
T/F, Basal ganglia & cerebellum do not directly project to lower motor neurons? so which ones can?
T; Upper motor neurons project to lower motor neurons located in the spinal cord and brainstem
what are the descending motor pathways?
Lateral motor systems
Medial motor systems
where does the coritcospinal tract lie?
posterior limb
