26 Nervous System (Spinal Cord Anatomy) Flashcards
What are the different sections of the spinal cord?
Cervical: 7 vertebrae
Thoracic: 12 vertebrae
Lumbar: 7 vertebrae
Sacral: 5 vertebrae
How many spinal nerves are there?
31 vertebrae, 31 pairs spinal nerves
Spinal nerves exit the spinal cord at the IV foramen superior to vertebrae, and are named for the vertebral segment immediately below them
What are the 5 layers around the spinal cord?
Epidural space: filled with fat and veins
Dura mater: extension of dura mater in the brain
Arachnoid mater: intermediate membrane, web like extensions extend from arachnoid space across subarachnoid space to anchor to the pia mater
Subarachnoid space: filled with CSF
Pia mater: internal membrane. delicate shelves of pia mater (denticulate ligaments) connect spinal cord to pia mater)
What are the 4 nerve plexuses in the spinal cord?
cervical plexus
brachial plexus
lumbar plexus
sacral plexus
What is the path of the spinal cord from superior to inferior?
Begins superiorly at the foramen magnum of the skull
Cord terminates at approximately the first or second lumbar vertebrae
End of the spinal cord is called the conus medullaris
conus medullaris continues as the filum terminale and anchors the spinal cord to the coccyx
What are the different horns of the spinal cord?
Dorsal horns: cell bodies of interneurons
Ventral horns: cell bodies of somatic motor neurons
Lateral horns: located at the thoracic and superior sacral spine only. cell bodies for autonomic motor nerves innervating the viscera
What are the different horns of the spinal cord?
Dorsal roots: sensory / afferent fibres, carry sensory input from the body to the CNS
ventral roots: all axons of motor / efferent fibres. also carries the axons of autonomic motor fibres from lateral horns in the thoracic and superior lumbar spine
What is the dorsal root ganglion? (DSG)
a cluster of afferent / sensory nerve cells
