# 1. Anatomy Flashcards
Name the meninges and the spaces.
- epidural space
1. dura mater - subdural space
2. arachnoid mater - subarachnoid space
3. pia mater
Describe the dura mater
- most superficial
- dense irregular CT
- tough momma
Describe the arachnoid mater
- middle layer
- avascular
- delicate collagen fibers and some elastic fibers
What is in the subarachnoid space?
cerebral spinal fluid (CSF)
Describe the pia mater
- innermost layer
- thin and transparent (saran wrap)
- adheres to surface of spinal cord & brain
- lots of blood vessels to supply spinal cord
What are denticulate ligaments?
- extensions of pia mater that suspend the spinal cord in the middle
- protect against sudden displacement
What is the length of the spinal cord?
from the medulla oblongata to L2 (more specifically between L1 and L2)
-newborns can extend to L3 or L4.
Where are the enlargements in the spinal cord?
- cervical enlargement - from C4-T1; nerves to and from the arms
- lumbar enlargement - from T9-T12; nerves to and from the legs
What is the conus medullaris?
-end of the spinal cord
What are filum terminale?
- extensions of pia mater that runs from conus medullaris to coccyx
- anchors the spinal cord to the coccyx
What is the cauda equina?
- the spinal nerves at the end of the spinal cord that don’t exit the vertebral column when they exit the cord. (ie. the L5 spinal nerve exits the spinal cord at L2 but stays in the vertebral column until L5)
- looks like a horses tail
What are rootlets?
bundles of axons that come directly off the spinal cord
What are the protective structures of the spinal cord?
- vertebral column
- CSF
- meninges
Which root has sensory axons?
Posterior (dorsal) root
Which root has motor axons?
Anterior (ventral) root
True or False: The posterior root contains efferent axons.
False. The posterior root (sensory axons) is afferent (going towards the spinal cord). The anterior root (motor axons) is efferent (traveling away from the spinal cord)
Where are sensory cell bodies located?
in the posterior (dorsal) root ganglion.
Where are motor cell bodies located?
in the CNS (anterior grey horn or the brain)
Why is white matter white?
because the bundles of axons are myelinated
What makes up the grey matter?
- dendrites and cell bodies of neurons
- unmyelinated axons
- neuroglia
What is the area of grey matter that connects the two sides called?
the grey commissure
What is the central canal?
a canal that runs down the center of the whole spinal cord and is filled with CSF
What is in the posterior grey horn?
incoming sensory axons and cell bodies of interneurons
What is in the anterior grey horn?
motor cell bodies
What is in the lateral grey horn?
autonomic cell bodies
Where is the lateral grey horn located?
only in the thoracic-upper lumbar region
What are bundles of axons in the CNS called?
tracts
What are bundles of axons in the PNS called?
nerves
What are clusters of cell bodies in the CNS called?
nuclei
What are clusters or cell bodies in the PNS called?
ganglion
What the layers of spinal nerves?
endoneurium, perineurium, epineurium
What is the endoneurium?
- the innermost layer of spinal nerves
- wraps individual axons
What is the perineurium?
- the middle layer of spinal nerves
- wraps fascicles
What is the epineurium?
- the outer layer of spinal nerves
- wraps entire nerve
What are names the of Rami?
- posterior (dorsal) ramus
- anterior (ventral) ramus
- meningeal branch
- rami communicantes
Where does the posterior ramus go?
to the posterior. - muscles & skin of posterior trunk
Where does the anterior ramus go?
to the limbs (muscles and skin), anterior and lateral trunk
-looks like a continuation of spinal nerves
Where does the meningeal branch go?
- back to the vertebral canal
- supplies vertebrae, vertebral ligaments, blood vessels of spinal cord & meninges.
Where does the rami communicantes go?
the autonomic nervous system
What are the blood vessels that supply nerves called?
vasa neuvorum
