Spinal Cord Anatomy Flashcards
Where is the spinal cord?
Vertebral canal (vertebral foramina of the spine)
Where does the spinal cord end?
Around L1/L2 in a full grown adult
What are the two enlargements on the spinal cord?
Cervical enlargement, lumbar enlargement; created by larger amounts of cell bodies/synapses
What is the end of the spinal cord?
Conus medullaris
What encases the spinal cord?
The meninges
What connects the end of the spinal cord to the sacrum?
Filum terminale
What nerves come off of the spinal cord?
Spinal nerves
What nerves come off of the brainstem?
Cranial nerves
What is the connection between spinal nerve neruons and the spinal cord?
Nerve root
What is the collective name for the nerve roots that extend from the conus medullaris?
Cauda equina
True or false: nerve roots insert underneath all three layers of meninges on the spinal cord
False. They insert between the arachnoid mater and pia mater
Why would a spinal tap be performed between lumbar vertebrae?
The cauda equina is a safer spot to draw than the spinal cord because the nerve roots will move out of the way of the needle, and if one gets damaged it’s less devastating than the spinal cord as a whole
True or false: grey matter is deep to the white matter in the spinal cord
True. Arrangement of grey and white matter in the spinal cord is opposite that of the brain
What is the enlargement of the dorsal root?
Dorsal root ganglion
What is found in the dorsal root ganglion?
Unipolar sensory neuron cell bodies
How can you recognize a cross-section of the cervical spinal cord?
About equal proportions of white/grey matter
How can you recognize a cross-section of the lumbar spinal cord?
About equal grey/white matter or more grey than white
How can you recognize a cross-section of the thoracic spine?
Less grey than white matter
Why is there so little grey matter in the thoracic spine?
Fewer cell bodies because there are no nerves serving the limbs
Why is there more white matter in the cervical spinal cord?
More axons carrying information from the lower regions; no need for axons from more superior regions to travel through the thoracic/lumbar spine
What functions are the posterior/dorsal grey horns associated with?
Somatic and visceral sensory
What functions are the lateral grey horns associated with?
Visceral motor
What functions are the anterior/ventral grey horns associated with?
Somatic motor
Ascending tracts of the white matter carry what?
Sensory information
Descending tracts of the white matter carry what?
Motor information
The dorsal root carries what kind of information?
Sensory
What can be found at the dorsal nerve roots?
Axon terminals of sensory nerves
Where are sensory neurons synapsing with the spinal cord?
Dorsal/posterior grey horn
What can be found at the ventral nerve roots?
Many dendrites of motor neurons
Where are motor neurons synapsing with the spinal cord?
Anterior/ventral grey horn, lateral grey horn for visceral motor
What are the branches off the spinal nerves that can contain both motor and sensory nerve axons?
Rami (singular ramus)
