00:00 / 00:00
Anatomy of the brainstem
0 / 1 complete
Our central nervous system is made up of the cerebrum, the cerebellum, the brainstem and the spinal cord. The brainstem is a trunk-like part that sits in the posterior cranial fossa and connects the spinal cord inferiorly with the forebrain superiorly.
The brainstem is made up of white and gray matter. The white matter contains many ascending and descending fibers that act like a highway, allowing information to travel to and from the spinal cord and the higher parts of the central nervous system.
Some of these collections of nuclei serve as centers for life sustaining reflexes, like those involved with breathing and our heartbeat, others coordinate states of alertness or arousal, while others mediate motor activities and relay sensory information.
On either side of it, there are two bumps called the pyramids, which contain axons of the corticospinal, or pyramidal, tract.
Before entering the spinal cord, these fibers cross over to the opposite side, forming the decussation of the pyramids.
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.