Editing Brainstem (section)

{{short description|Posterior part of the brain, adjoining and structurally continuous}}
{{more citations needed|date=January 2013}}
{{Infobox brain
| Name            = Brainstem
| Latin           = truncus encephali
| Image           = 1311 Brain Stem.jpg
| Caption         = The three distinct parts of the brainstem are colored in this sagittal section of a human brain.
| IsPartOf        = [[Brain]]
| Components      = [[Medulla oblongata|Medulla]], [[pons]], [[midbrain]]
| Artery          =
| Vein            =
}}
[[File:3D Medical Animation Mid-Brain Different Parts.jpg|alt=3D Medical Animation Still Shot Showing Different Parts of Mid-Brain|thumb|261x261px|A 3D medical animation still shot showing different parts of the midbrain.]]
The '''brainstem''' (or '''brain stem''') is the posterior stalk-like part of the [[brain]] that connects the [[cerebrum]] with the [[spinal cord]].<ref name="Singh">{{cite book |last1=Singh |first1=Vishram |title=Textbook of Anatomy Head, Neck, and Brain; Volume III |date=2014 |isbn=9788131237274 |page=363 |publisher=Elsevier India |edition=2nd}}</ref> In the [[human brain]] the brainstem is composed of the [[midbrain]], the [[pons]], and the [[medulla oblongata]].<ref name="Singh"/> The midbrain is continuous with the [[thalamus]] of the [[diencephalon]] through the [[tentorial notch]], and sometimes the diencephalon is included in the brainstem.<ref name="Haines">{{cite book |last1=Haines |first1=D |last2=Mihailoff |first2=G |title=Fundamental Neuroscience for Basic and Clinical Applications |date=2018 |isbn=9780323396325 |page=152|publisher=Elsevier |edition=5th}}</ref>

The brainstem is very small, making up around only 2.6 percent of the brain's total weight.<ref name="Haines1">{{cite book |last1=Haines |first1=D |last2=Mihailoff |first2=G |title=Fundamental Neuroscience for Basic and Clinical Applications |date=2018 |isbn=9780323396325 |page=195|publisher=Elsevier |edition=5th}}</ref> It has the critical roles of regulating [[heart]] and [[respiratory system|respiratory]] function, helping to control [[heart rate]] and [[breathing rate]].<ref name="Encyclopedia Britannica">{{Cite web|title=Brainstem {{!}} Definition, Structure, & Function|url=https://www.britannica.com/science/brainstem|website=Encyclopedia Britannica|language=en|access-date=2020-05-13}}</ref> It also provides the main motor and sensory nerve supply to the [[face]] and [[neck]] via the [[cranial nerves]]. Ten pairs of cranial nerves come from the brainstem.<ref>{{Cite web|title=Cranial Nerve Nuclei and Brain Stem Circulation|url=https://nba.uth.tmc.edu/neuroanatomy/L10/Lab10p01_index.html|website=Neuroanatomy Online|access-date=2020-05-13}}</ref> Other roles include the regulation of the [[central nervous system]] and the body's [[sleep cycle]].<ref name="Encyclopedia Britannica" /> It is also of prime importance in the conveyance of motor and sensory pathways from the rest of the brain to the body, and from the body back to the brain.<ref name="Encyclopedia Britannica" /> These pathways include the [[corticospinal tract]] (motor function), the [[dorsal column-medial lemniscus pathway]] ([[Fine touch#Fine touch and crude touch|fine touch]], [[Cutaneous receptor#Modalities|vibration sensation]], and [[proprioception]]), and the [[spinothalamic tract]] ([[pain]], temperature, itch, and [[Somatosensory system#Fine touch and crude touch|crude touch]]).<ref>Kolb, B. & Whishaw, I. Q. (2009). ''Fundamentals of human neuropsychology'': 6th ed., New York: Worth Publishers.{{ISBN?}}</ref>