What is the dural sac? What meningeal layer is it composed of?
A long tubular sheath within the vertebral canal; formed by the dura mater
What ligament of the pia mater suspends the spinal cord in the dural sac?
The denticulate ligament (looks like sawtooth)
Identify the structural components and functional parts of the nervous system
Structure: CNS (brain and spinal cord) and PNS (cranial and spinal nerves);
Functional: Somatic nervous (embryonic somites and branchial arches) and visceral nervous (both have motor and sensory); Motor (efferent) and sensory (afferent)
What is the cauda equina?
The dorsal and ventral roots of the lower lumbar, sacral, and coccygeal spinal nerves that need to descend within the vertebral canal to reach their intervertebral foramina (since their intervetebral disks exit superior to L1/L2)
Define a somatic nerve plexus
A network of nerve fibers: formed by the ventral ramus (always) of certain spinal nerves. E.g. cervical plexus, brachial plexus, lumbar plexus, sacral plexus.
Describe where each of the spinal nerves exit the spinal cord in relation to the vertebrae
C1 exits between occipital bone and atlas; C2-C7 exit immediately above corresponding vertebrae; C8 exits between C7 and T1; all others exit below their respective vertebrae
Describe the basic features of the neuron
Cell body, dendrites, and axon (aka fibers); communicate via synapses using neurotransmitters
At what vertebral level does the dural sac end?
S2 (where it is attached)
What is the filum terminale internum? What is the filum terminale externum (aka...?)
At the apex of the cord, pia mater continues down with the cauda equina to end of the dural sac, pierces it, and attaches to the tip of the coccyx.
What are the meninges?
The protective barrier between bone and soft tissue of the CNS; they include the Dura mater, the arachnoid mater, and the pia mater
