C13 12-13-19-20 Flashcards
Endoneurium
Covers a single axon
Perineurium
Covers a bundle (fascicle) of axons
Epineurium
Surrounds a group of fascicles and blood vessels
Spinal cord function?
- Relay station (sensory/motor) 2. Processing center (spinal reflexes
Gross anatomy features of spinal cord?
Cervical/lumbar enlargements, conis medullaris, cauda equina, filum terminale, spinal nerves (31) named after vertebrae protecting them.
Spinal cord stops at lumbar two. 1/2” wide
Cervical/lumbar enlargements?
3/4” enlargements where the nerves serving the upper and lower limbs arise.
Conus Medularis
Spinal cord Tapers into cone-shaped structure after the spinal cord terminates.
Cauda Equina
Collection of nerve roots at the inferior end of the vertebral canal. Horse tail
Filum Terminale
A fibrous extension of the conus, covered by pia mater, anchors the spinal cord to the coccyx (end of cauda equina)
Are the dura, arachnoid and pia mater continuous into the spine?
Yes, with a minor difference - no periosteal layer in the dura mater.
What is in the grey matter of the spinal cord?
Commisure - links “butterfly” sides of grey matter. Horns - Dorsal, ventral and lateral. Nerve cell bodies! Interior of spinal cord
How is the grey matter of the spinal cord organized?
Into areas of sensory and motor nuclei - dorsal, ventral and lateral horns.
What do the Lateral horns consist of?
VM Cell bodies (autonomic motor neurons that serve visceral organs)
What do the Ventral horns consist of?
SM Cell bodies (skeletal muscle)
What do the Dorsal horns consist of?
SS and VS nuclei
What are the two grooves on the spinal cord?
Ventral median fissure, dorsal median sulcus
How to tell posterior from anterior on spinal cord?
Dorsal horns connect to outer edge and are thinner than anterior
What is the white matter of the spinal cord?
Axons –> bundles/fascicles/tracts –> columns/funiculi.
Funiculus
A column of axons - dorsal, ventral, anterior “white ropes”
What do spinal nerves contain?
mixed nerves (two-way highway)
What do the Dorsal roots consist of?
Sensory neurons (SS, VS) (one way highway)
What do the Ventral roots consist of?
Motor neurons (VM, SM) (one way highway)
Names of axon on unipolar neuron?
Peripheral process (receptive endings) - central process
Spinal puncture?
where cfs is flowing, under arachnoid space, below lumbar 2 (sample or anaesthesia)
How is white matter organized?
dorsal, lateral, and anterior ventral funiculi.
A column/funiculi is then broken down into tracts (banks of elevators).
(lateral spinothalamic tract, lateral corticospinal tract)
Where are the cell bodies of third order neurons?
thalamus
Ganglion
collection of cell bodies in the PNS
Dorsal root ganglion contain? (sensory pathway)
Cell bodies of first order neurons
Dorsal horn contains? (sensory pathway)
Cell bodies of second order neurons
Thalamus contains? (sensory pathway)
Cell bodies of third order neurons
Terminal ganglia location/contents?
next to organ or in organ, postganglionic cell bodies
Sympathetic chain ganglia location/contents?
sympathetic trunk, postganglionic cell bodies
Prevertebral ganglia location/contents?
close to abdominal arteries, postganglionic cell bodies
- List the major spinal cord tracts, and classify each as a motor or sensory tract.
Sensory:
- –Dorsal column medial lemniscal pathway - touch/conscious proprioception
- –Spinothalmic (lateral and ventral) - pain/temp
- –Spinocerebellar (ventral/dorsal) - proprioceptor input from golgi tendon/muscle spindle/joint capsules.
Motor: Lateral Corticospinal tract - voluntary control of skeletal muscle.
