NETTER - Neuroscience Flash Cards

S3 Spinal Cord Cross Section
1. Fasciculus gracilis
2. Lateral corticospinal tract
3. Rubrospinal tract
4. Anterolateral system
5. Marginal zone
6. Substantia gelatinosa
7. Nucleus proprius
8. Sacral parasympathetic nucleus (intermediomedial cell column)
9. Lower motor neurons in anterior horn
10. Anterior white commissure
Comment: In an adult, the sacral segments of the spinal cord
are located at the level of the T1 vertebral body. Trauma or a
tumor at this level can cause conus medullaris syndrome, which
involves (1) flaccid paralysis of the muscles of the pelvic floor
(lower motor neuron damage); (2) a flaccid bladder with overflow
incontinence (loss of parasympathetic preganglionic neurons); (3)
constipation and diminished bowel function (loss of parasympathetic
preganglionic neurons); (4) loss of erectile function in males (loss
of parasympathetic preganglionic neurons); (5) “saddle” anesthesia
(loss of sensory processing); and (6) a possible sensation of pain
experienced in the gluteal or perineal region.
Regional Neuroscience See book 10.5