Spinal cord anatomy Flashcards
Meninges and spaces
Epidural space - Dura mater-subdural space - arachonoid mater -subarachoid space - pia mater - dentriculate ligaments
Protective structures of spinal cord
meninges - membranes
Vertebrae - bone
Fluid - CSF (cerebrospinal fluid)
Superficial layer of meninges
Dura mater: dense irregular connective tissue, thick and strong
Middle layer meninges
arachoid mater: avascular, delicate collagen fibers and some elastic fibers. Spider web
Innermost layer of meninges
Pia mater, thin and transparent, adheres to surface of spinal cord and brain (saran wraps)
Space between vertebral canal and dura mater
Epidural space (filled with extracellular fluid)
Space between dura mater and arachnoid mater
Subdural space (Extracellular space)
space between arachnoid mater and pia mater
subarachnoid space
extensions of pia mater that suspend the spinal cord in the middle
Denticulate ligaments: protect against sudden displacement
Spinal cord external anatomy shape, length
Oval (flattened anteriorly and posteriorly) from medulla oblongata to L2 (in new borns it goes to L3-L4)
Cervical enlargement
From C4 to T1
Nerves to end and from the arms
Lumber enlargement
from T9 to T12
nerves to and from legs
Tapering end of spinal cord
conus medullaris, ends between L1 and L2
Extension of pia mater
filum terminale, runs from conus medullaris to coccyx, anchors spinal cord to coccyx
Spinal nerves at the end of spinal cord
cauda equina
Paths of communication between spinal cord and specific areas of the body
Spinal nerves. Peripheral nerves system
smaller bundles of axon
rootlet
two bundle of axons called
root
Posterior (dorsal) root and rootlets
contain only SENSORY axons, which conduct nerve impulses from sensory receptors in the skin, muscles and internal organs into the central nervous system. Afferent
Anterior (ventral) root and rootlet
contain axons of MOTOR neurons, which conduct nerve impulses from the CNS to effectors (muscles and glands)
White matter of spinal cord consists
bundles of myelinated axons of neurons
Grey matter
Unmyelinated axons
Dendrites and cell bodies
Neuroglia
Central Canal
entire length of the spinal cord and is filled with cerebrospinal fluid
Gray commisure
forms the crossbar of H
A narrow furrow on the posterior side
Post median sulcus
wide groove on the anterior side
Anterior median fissure/sulcus
Posterior Grey Horns
incoming sensory axons and all bodies and axons of interneurons
Anterior Grey Horns
Outgoing motor axons and all bodies of interneurons
Lateral Grey Horns
Only found in T-spine and upper lumber
Autonomic motor cell bodies
Bundles of Axons in the CNS
Tracts
Bundles of axons in the PNS
Nerves
Clusters of cell bodies in the CNS
Nuclei
Clusters of cell bodies in the PNS
Ganglion
Spinal nerves covering
Endoneurium, Perineurium, Epineurium
Rami
- Posterior Ramus (mm+skin of posterior trunk)
- Anterior Ramus (mm+skin of limbs, skin of lat and ant trunk)
- Meningeal branch ( re-enter vertebral canal to supply vertebra, vertebral ligament, Blood vessels of spinal cords, meninges)
- Rami communicantes (rami communications, ANS)