Chapter 21 - Spinal Cord and Spinal Nerves
The bundle of nervous tissue that runs from the brain to the first to third lumbar vertebrae and provides a conduction pathway to and from the brain.
The terminal end of the spinal cord.
Occurs near lumbar vertebral levels 1 (L1) and 2 (L2).
Continuation of the conus medullaris and is the thin cord-like structure that extends down to the end of the spinal canal.
The roots of the spinal nerves controlling movement and sensation in the legs. These nerve roots are located in the lower spine.
Cross section of the spinal cord; looks like a butterfly or "H"
Dorsal projections of the gray matter.
Ventral projections of the grey matter.
Lateral outpocketing of grey matter that can be observed in the thoracic and lumbar regions of the spinal cord.
Central area of grey matter connecting the two ventral regions.
Surrounded by the gray commissure, contains CSF.
Point of entry of interneurons and sensory fibers into the spinal cord from the body.
Dorsal Root Ganglion
Peripheral collection of cell bodies of first-order afferent neurons whose central axons enter the spinal cord.
Point of exit for axons of motor neurons of the somatic nervous system, so their signal can be transmitted into adjacent spinal nerves.
Surrounds the gray matter and is bisected by fissures.
Anterior Median Fissure
More open fissure
Posterior Median Sulcus
Posterior Median Septum
A sheet of glial tissue in the midsagittal plane of the spinal cord that extends from the posterior median sulcus toward the gray commissure and that partitions the posterior part of the spinal cord into right and left halves
White Column (Dorsal Funiculus)
Dorsal section of white matter
White Column (Lateral Funiculus)
Lateral section of white matter
White Column (Ventral Funiculus)
Ventral section of white matter
Collection of axons that conduct sensory inpulses to the brain.
Spinal Nerves Mixed
All spinal nerves are mixed nerves (carry signals to and from the spinal cord)
The posterior branches of the spinal nerves. (Smaller than ventral rami.)
The anterior branches of the spinal nerves. (Larger than dorsal rami)
Interlacing nerve networks that occur in the cervical, brachial, lumbar, and sacral regions and primarily serve the limbs.
Sciatic Nerve (Largest)
Common Fibular Nerve
What is A?
What is B?
What is C?
What is D?
What is E?
Dorsal Median Sulcus
What is F?
What is G?
What is H?
What is I?
What is J?
What is K?
What is L?
Ventral Medium Fissure
What is M?
Dorsal Ganglia Root
What is N?
What is O?
What is P?