2.0 neuro - spinal cord Flashcards
Origin of the spinal nerves?
Spinal cord
Essential functions of the spinal cord
- Relays sensory information from periphery to brain, somatic and viseral
- Contains motor neurons, somatic and viseral
- Local connections between motor and sensory information; reflexes
- Relays motor information from brain to muscles, somatic and viseral
Organization of gray and white matter in the spinal cord
Outer layer = white matter; columns = funiculi
Inner layer = gray matter; two dorsal two ventral horns
What are funiculi
Columns of white matter in the spinal cord
What do ascending tracts in the spinal cord relay
Sensory afferent information
What do descending tracts in the spinal cord relay
Motor efferent information
What is the purpose of epidural adipose tissue in the spinal cord
Found between the dura mater and bones of the vertebral canal to prevent dura from adhering to spinal column; allows spinal movement
What is found surrounding the dura mater in the spinal cord
Epidural adipose tissue
What meningeal layers surround the spinal cord along its entire length
Pia mater, arachnoid mater, dura mater (all)
The spinal cord ends at what vertebra
L1-2
What is the name of the termination of the spinal cord
Conus medullaris
The dura mater ends at what vertebra
S1
What is the cauda equina
Bundle of spinal nerves below the termination of the spinal cord traveling to their exit points
What meninges specializations exist in the spinal cord
Filum terminale internum; Filum terminal externum
What is the filum terminale internum
Thread-like extension of the pia mater from the conus medullaris of the spinal cord; anchors the spinal cord to the inside of the dural sac
What is the filum terminale externum
Thread-like extension of the dura mater below the end of the dura sac, attaches to the coccyx; anchors the dural sac to the vertebral column
5 regions of the spinal cord
Cervical, thoracic, lumbar, sacral, coccygeal
2 enlargements of the spinal cord
Cervical, lumbar
Why does the ratio of gray to white matter change along the length of the spinal cord
Most superior spinal cord has more white matter because it contains everything coming from the brain and added from the periphery. Most inferior spinal cord has more gray matter because many myelinated fibers have already made synapses higher up in the spinal cord
Two divisions of the gray matter of the spinal cord
Dorsal horn, ventral horn
What type of information is relayed by the dorsal horn of the spinal column
Sensory
What type of information is relayed by the intermediate zone of the spinal column
Visceral motor and sensory
What type of information is relayed by the ventral horn of the spinal column
Somatic motor
Which nuclei / cell columns travel in the dorsal horn
Substantia gelatinosa, nucleus proprious, dorsal nucleus
Which nuclei / cell columns travel in the intermediate zone
Intermediolateral cell column, visceral sensory relay
Which nuclei / cell columns travel in the ventral horn
Motor neuron pool; medial and lateral
Which nuclei / cell columns are continuous along the entire length of the spinal column
Ventral horn medial, substantia gelatinosa, nucleus proprius
Explain the somatotopic map within the ventral horn of the spinal cord
- Medial motor neurons innervate proximal muscles
- Lateral motor neurons innervate distal muscles
- Dorsal motor neurons innervate flexor muscles
- Ventral motor neurons innervate extensor muscles
How is the dura different in the vertebral canal compared to that of the cranium
Dura only has one layer in the vertebral canal instead of two layer to create specializations in the cranium
What branches of the vertebral artery exist to supply the spinal cord
1 ventral (anterior) branch, 2 dorsal (posterior) branches
What is the aorta’s role in spinal cord blood supply
Aortic branches supplement the ventral and dorsal branches
How does venous drainage run relatively along the spinal cord
Parallels arterial supply
