Editing Central nervous system (section)

===Brain===
{{main article|Brain}}
At the anterior end of the spinal cord lies the brain.<ref name="Kandel" /> The brain makes up the largest portion of the CNS. It is often the main structure referred to when speaking of the nervous system in general. The brain is the major functional unit of the CNS. While the spinal cord has certain processing ability such as that of [[spinal locomotion]] and can process [[reflex]]es, the brain is the major processing unit of the nervous system.<ref>{{cite web | vauthors = Thau L, Reddy V, Singh P | title = Anatomy, Central Nervous System | publisher = StatPearls | date=January 2020 | url = https://www.ncbi.nlm.nih.gov/books/NBK542179/ | access-date = 13 May 2020 | pmid = 31194336}}</ref><ref>{{cite web|url=http://www.cancer.ca/en/cancer-information/cancer-type/brain-spinal/brain-and-spinal-tumours/the-brain-and-spinal-cord/?region=on|title=The brain and spinal cord – Canadian Cancer Society|website=www.cancer.ca|language=en|access-date=2019-03-19}}</ref>

====Brainstem====
{{main article|Brainstem}}
The brainstem consists of the [[medulla oblongata|medulla]], the [[pons]] and the [[midbrain]]. The medulla can be referred to as an extension of the spinal cord, which both have similar organization and functional properties.<ref name="Kandel" /> The tracts passing from the spinal cord to the brain pass through here.<ref name="Kandel" />

Regulatory functions of the medulla nuclei include control of [[blood pressure]] and [[breathing]]. Other nuclei are involved in [[balance (ability)|balance]], [[taste]], [[hearing]], and control of muscles of the [[face]] and [[neck]].<ref name="Kandel" />

The next structure rostral to the medulla is the pons, which lies on the ventral anterior side of the brainstem. Nuclei in the pons include [[pontine nuclei]] which work with the [[cerebellum]] and transmit information between the cerebellum and the [[cerebral cortex]].<ref name="Kandel" />
In the dorsal posterior pons lie nuclei that are involved in the functions of breathing, sleep, and taste.<ref name="Kandel" />

The midbrain, or mesencephalon, is situated above and rostral to the pons. It includes nuclei linking distinct parts of the motor system, including the cerebellum, the [[basal ganglia]] and both [[cerebral hemisphere]]s, among others. Additionally, parts of the visual and auditory systems are located in the midbrain, including control of automatic eye movements.<ref name="Kandel" />

The brainstem at large provides entry and exit to the brain for a number of pathways for motor and autonomic control of the face and neck through cranial nerves,<ref name="Kandel" /> Autonomic control of the organs is mediated by the [[Vagus nerve|tenth cranial nerve]].<ref name="Fitzgerald" /><!-- page 98-199 --> A large portion of the brainstem is involved in such autonomic control of the body. Such functions may engage the [[heart]], [[blood vessels]], and [[pupil]]s, among others.<ref name="Kandel" />

The brainstem also holds the [[reticular formation]], a group of nuclei involved in both [[arousal]] and [[alertness]].<ref name="Kandel" />

====Cerebellum====
{{main article|Cerebellum}}
The cerebellum lies behind the pons. The cerebellum is composed of several dividing fissures and lobes. Its function includes the control of posture and the coordination of movements of parts of the body, including the eyes and head, as well as the limbs. Further, it is involved in motion that has been learned and perfected through practice, and it will adapt to new learned movements.<ref name="Kandel" />
Despite its previous classification as a motor structure, the cerebellum also displays connections to areas of the cerebral cortex involved in language and [[cognition]]. These connections have been shown by the use of [[medical imaging]] techniques, such as [[fMRI|functional MRI]] and [[Positron emission tomography]].<ref name="Kandel" />

The body of the cerebellum holds more neurons than any other structure of the brain, including that of the larger [[cerebrum]], but is also more extensively understood than other structures of the brain, as it includes fewer types of different neurons.<ref name="Kandel" /> It handles and processes sensory stimuli, motor information, as well as balance information from the [[vestibular organ]].<ref name="Kandel" />

====Diencephalon====
{{main article|Diencephalon|Thalamus|Hypothalamus}}
The two structures of the diencephalon worth noting are the thalamus and the hypothalamus. The thalamus acts as a linkage between incoming pathways from the peripheral nervous system as well as the optical nerve (though it does not receive input from the olfactory nerve) to the cerebral hemispheres. Previously it was considered only a "relay station", but it is engaged in the sorting of information that will reach cerebral hemispheres ([[neocortex]]).<ref name="Kandel" />

Apart from its function of sorting information from the periphery, the thalamus also connects the cerebellum and basal ganglia with the cerebrum. In common with the aforementioned reticular system the thalamus is involved in wakefulness and consciousness, such as though the [[Suprachiasmatic nucleus|SCN]].<ref name="Kandel" />

The hypothalamus engages in functions of a number of primitive emotions or feelings such as [[hunger]], [[thirst]] and [[maternal bond]]ing. This is regulated partly through control of secretion of [[hormone]]s from the [[pituitary gland]]. Additionally the hypothalamus plays a role in [[motivation]] and many other behaviors of the individual.<ref name="Kandel" />

====Cerebrum====
{{main article|Cerebrum|Cerebral cortex|Basal ganglia|Amygdala|Hippocampus}}
The cerebrum of cerebral hemispheres make up the largest visual portion of the human brain. Various structures combine to form the cerebral hemispheres, among others: the cortex, basal ganglia, amygdala and hippocampus. The hemispheres together control a large portion of the functions of the human brain such as emotion, memory, perception and motor functions. Apart from this the cerebral hemispheres stand for the cognitive capabilities of the brain.<ref name="Kandel" />

Connecting each of the hemispheres is the [[corpus callosum]] as well as several additional commissures.<ref name="Kandel" />
One of the most important parts of the cerebral hemispheres is the [[Cortex (anatomy)|cortex]], made up of gray matter covering the surface of the brain. Functionally, the [[cerebral cortex]] is involved in planning and carrying out of everyday tasks.<ref name="Kandel" />

The hippocampus is involved in storage of memories, the amygdala plays a role in perception and communication of emotion, while the basal ganglia play a major role in the coordination of voluntary movement.<ref name="Kandel" />