ANS and spine Flashcards
Meninges
Protective coverings for the spinal cord
Layers of meninges
Dura mater
Arachnoid mater
Pia mater
Dura mater
Surrounds the spinal cord, each segment forms the epineurium
Outer layer of meninges that is dense collagenous tissue
Arachnoid mater
Middle layer of meninges
Arachnoid space
Deep to arachnoid mater, contains web like projections and CSF
Pia mater
Loose CT that is connected to the spinal cord and forms dentate ligaments and filum terminale
Epineurium
Surrounds the entire nerve projection
Dentate ligament
Runs along the spinal cord and stabilizes
Filum terminale
Fibrous band that extends from conus medullaris and connects to the coccyx, stabilizes the spinal cord
Vertebral levels of the spinal cord
C-7
T-12
L-5
S-5
Where does the spinal cord end
L1/L2
Why is there a vertebrosegmental discrepancy between spinal cord and vertebral column
Vertebral column grew faster than the spinal cord during development
Spinal cord levels of the spine
C-8
T-12
L-5
S-5
Cervical vertebra and spinal cord level discrepancy
Occipital bone is technically C1, and the C1 spinal nerve exits below that
So the spinal nerves leaving the cervical spine exit above the associated vertebral segment
Vertebrosegmental discrepancies in Cervical
Nerve exits above associated vertebra
Nerve exits horizontally
Vertebrosegmental discrepancies in thoracic
Nerve exits below the associated vertebra
In upper T nerve exits horizontally to assoc. vertebrae
Lower T, nerve is descending more vertically to get to associated vertebrae
Vertebrosegmental discrepancies in lumbar
Spinal nerve goes down vertically to reach the associated vertebrae
Vertebrosegmental discrepancies in sacral
Since in the cauda equina, all spinal nerves come from L1-L2 and descend to associated vertebrae
Gray matter
Synapses of cell bodies
Parts of the gray matter
Ventral horn
Lateral horn
Dorsal horn
Ventral horn
Somatic motor neuron cell body
Lateral horn
Visceral motor neuron
Found in T1-L2
Dorsal horn
Receive sensory info (somatic and visceral)
Why is there swelling in the cervical and lumbar vertebral regions
More synapsing (cell bodies) in the parts of the spine where the limbs are
White matter
Axons surrounded by myelin sheath
Sending and receiving signals
Amount of white matter matter as you go from sacral to cervical
Increases, more neurons entering in to go to the brain
Dorsal column tract
Between posterior horns (dorsal horns)
Ascending ipsilateral sensory, fine touch, vibration, proprioception
Anterolateral tract
Ascending contralateral tract for pain and temperature