Lecture 16: Spinal Cord Flashcards
CNS Consists Of
Brain
Spinal Cord
PNS Consists Of
Cranial Nerves
Spinal Nerves
Nerve
Bundles of neurons and neuralgia cells
Cranial Nerves Location
Connected directly to brain/brain stem
Spinal Nerves Location
Branch off of spinal cord and have others branching off of them
How Long Is The Spinal Cord?
About 18 inches
Intervertebral Foramen
Where spinal nerves exit,
When vertebral bones are stacked together
Conus Medullaris
Tapered end of the spinal cord
Cauda Equina
Spinal nerve roots continue inferiorly
How Many Pairs of Spinal Nerves Are There?
31 pairs
How Many Cervical Nerves Are There?
8 pairs
How Many Thoracic Nerves Are There?
12 pairs
How Many Lumbar Nerves Are There?
5 pairs
How Many Sacral Nerves Are There?
5 pairs
How Many Coccygeal Nerves Are There?
1 pair
Spinal Nerve Consists Of
A joining of 2 nerve roots
Ventral Root
Anterior Side,
Contains axons of motor neurons,
OUT
Dorsal Root
Posterior Side,
Contains axons of sensory neurons,
IN
Dorsal Root Ganglia
Contain cell bodies of sensory neurons,
In PNS,
Combo of ventral and dorsal root
Denticulate Ligaments
Extend from pia mater to dura mater,
Stabilize side-to-side movement (horizontal)
Main Functions of Spinal Meninges (4)
- Specialized membranes that isolate spinal cord from surroundings
- Protect spinal cord
- Carry blood supply
- Continuous with cranial meninges
Dura Mater
Outermost layer of spinal cord,
Fuses with periosteum of occipital bone at foreman magnum,
Joins filum terminale in coccygeal ligament
Arachnoid Mater
Middle meningeal layer
Pia Mater
Inner meningeal layer,
Bound to underlying neural tissue by astrocytes