Editing Brainstem (section)

==Function==
The brainstem plays important functions in [[breathing]], [[heart rate]], [[arousal]] / [[consciousness]], [[sleep]] / [[wakefulness|wake]] functions and [[attention]] / concentration.<ref>{{citation | title=Simplified Brain Behavior Relationships | publisher=Brain Injury Association of Virginia | location=Alexandria, Virginia, US |year= 2005}}</ref>

There are three main functions of the brainstem:
# The brainstem plays a role in conduction. That is, all information relayed from the body to the cerebrum and cerebellum and vice versa must traverse the brainstem. The ascending pathways coming from the body to the brain are the sensory pathways and include the [[spinothalamic tract]] for pain and temperature sensation and the [[dorsal column-medial lemniscus pathway]] (DCML) including the [[gracile fasciculus]] and the [[cuneate fasciculus]] for touch, [[proprioception]], and pressure sensation. The facial sensations have similar pathways and will travel in the spinothalamic tract and the DCML.  Descending tracts are the axons of upper motor neurons destined to synapse on lower motor neurons in the [[Anterior horn of spinal cord|ventral horn]] and [[posterior horn of spinal cord|posterior horn]].  In addition, there are upper motor neurons that originate in the brainstem's vestibular, red, tectal, and reticular nuclei, which also descend and synapse in the spinal cord.
# The cranial nerves III-XII emerge from the brainstem.<ref>{{cite web |url=http://vanat.cvm.umn.edu/NeuroLectPDFs/CranialN-Lect.pdf |title=Lecture 6: Cranial Nerves |access-date=2012-11-10 |url-status=live |archive-url=https://web.archive.org/web/20130418031405/http://vanat.cvm.umn.edu/NeuroLectPDFs/CranialN-Lect.pdf |archive-date=2013-04-18 }}</ref> These cranial nerves supply the face, head, and viscera. (The first two pairs of cranial nerves arise from the cerebrum).
# The brainstem has integrative functions being involved in cardiovascular system control, respiratory control, pain sensitivity control, alertness, awareness, and consciousness.  Thus, brainstem damage is a very serious and often life-threatening problem.

===Cranial nerves===
[[File:Brain stem sagittal section.svg|thumb|A cross-section of the brainstem showing the multiple [[cranial nerve nucleus|nuclei]] of the ten pairs of [[cranial nerves]] that emerge from it]]
{{expand section|date=October 2016}}{{Main|Cranial nerves}}

Ten of the twelve pairs of cranial nerves either target or are sourced from the brainstem nuclei.<ref name="Purves">{{cite book|last1=Purves|first1=Dale|title=Neuroscience|date=2011|publisher=Sinauer|location=Sunderland, Mass.|isbn=978-0-87893-695-3|edition=5th.}}</ref>{{rp|725}} The nuclei of the oculomotor nerve (III) and trochlear nerve (IV) are located in the midbrain. The nuclei of the trigeminal nerve (V), abducens nerve (VI), facial nerve (VII) and vestibulocochlear nerve (VIII) are located in the pons. The nuclei of the glossopharyngeal nerve (IX), vagus nerve (X), accessory nerve (XI) and hypoglossal nerve (XII) are located in the medulla. The fibers of these cranial nerves exit the brainstem from these nuclei.<ref name="Vilensky">{{cite book|title=The Clinical Anatomy of the Cranial Nerves: The Nerves of 'On Olympus Towering Top'|last1=Vilensky|first1=Joel|last2=Robertson|first2=Wendy|last3=Suarez-Quian|first3=Carlos|publisher=Wiley-Blackwell|year=2015|isbn=978-1-118-49201-7|location=Ames, Iowa}}</ref>