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Neuroanatomical Structures




Thenervous system categorized into PNSand CNS.The PNS&nbspconsist of sensoryneurons&nbspwhichrun from receptors&nbspinformingCNS of the stimuli and the motorneurons&nbspwhichrun from CNS to&nbsptoeffectors&nbspwhichtake action. The&nbspCNS&nbspiscomposed of the brain and spinalcord.The&nbspPNSisalso divided to sensoryand the autonomicnervous systems (Domburg,1990).

Neuroanatomicalstructures are the (CNS)and PNS as shown in the diagram below.

Diagram1: diagram indicating the CNS in pink as well as peripheral inyellow.

CNSis part of brain mainly composed of spinal cord and brain. Thefunction of the CNS is to integrate the information received,harmonizing and impacting the activity, and body parts. As noted fromEdelson(1991), CNSis located in dorsal cavity where brain is in cranial cavity whilstthe spinal cord is in spinal cavity. It is worth noting that, thebrain is shield by skull while spinal cord is shield by vertebrae.

Thereare spinal nerves in spinal cord which connect it to the skin,muscles and skin. These nerves enable transfer of afferent andefferent sensory motors allowing involuntary and voluntary movementsof muscles in addition to senses perception (Edelson,1991).Each nerve carries the motor and sensory signals to and fro the CNSor brain mainly thalamus to provide the information. The followingdiagram shows the sensory and motor tracks to the brain.

Diagram2: a diagram showing the sensory tracks and motor tracks or neuronsto the brain

Thebrain is the largest part of CNS and is the main structure referredin the nervous structure (Domburg,1990).Brain is a processing unit or source of information in nervoussystem. Its parts are shown below.

Diagram3: a diagram showing parts of brain

Thebrain has four parts namely brain stem, cerebellum and Diencephalonand cerebrum. Thebrain stem gives the entry and exit of information to brain from theneck and face and thus involved in controls of blood vessels andheart. It is made up of medulla, pons and the midbrain as shown abovein diagram 3.

Themedulla is the additional room of the spinal cord, since it performsthe same function like the spinal cord and sensory and motor trackspasses here. Medulla nuclei regulate and controls&nbspbloodpressureand breathing. There are other medulla nuclei dealing withimbalance, taste and hearing and neck and facial muscles control.Pons which is located in anterior part of brain stem helps transmitsinformation to and fro cerebellum and cerebral cortex as shown in thediagram. It also affects the taste, sleep and breathing.

Themidbrain is located above pons, and has nuclei which link variousparts of motor system. It also controls the automatic eye movements.Cerebellum is slocated posteriorly as well as rostrally to the pons. It has manyholes and lobes and functions to coordinate the posture and movementof limbs, eyes and head and motion perfected through practice(Edelson,1991).

Diencephalonsarethalamus and the hypothalamus. Thalamus links incoming tracks fromPNS and optic nerve to cerebrum. It also sorts information. Inaddition, thalamus is engaged in consciousness and wakefulness.Hypothalamus functions in minor emotions like thirst, bonding andhunger through hormones. It also gets involved in behaviors changeslike motivations.

Cerebrumislocated in cerebral hemisphere or top part of brain is made up ofcombination of cortex, hippocampus, basal ganglia and amygdale(Titus, Revest &amp Shortland, 2007). They control many functions ofbrain such as memory, emotions, perceptions and motor function.Each is connected by corpus callosum. It has also cerebral cortexinvolved in planning and task performance. Hippocampus storesinformation while amygdale is involved in perception andcommunication while a ganglion is involved in voluntary movementcoordination (Domburg,1990).

Inother part peripheralnervous system&nbspispart of nervous system made up of ganglia and brain and situatedoutside brain and spinal cord. Its main function is to link CNS tolegs and other organs acting as a relay of communication to and frothe brain. It is not protected hence exposed to injuries and toxins.They are categorized into autonomic and somatic nervous system asshown below and are composed of eleven cranial axons (Maximino,2012).

Diagram3: a diagram showing the type of PNS and the type of neurons involvedin their function.

Thesomatic nervous system has twelve pairs of cranial nerves and 31pairs of spinal nerves as illustrated in the table below.




I Olfactory nerve



II Optic nerve



III Oculomotor nerve


Eyelid and eyeball muscle movement

IV Trochlear nerve


Eyeball muscle movement

V Trigeminal nerve


Facial and mouth sensation&nbsps and motor sensation e.g. chewing

VI Abducens nerve


Eyeballs movement

VII Facial nerve


Sensory:&nbsptastingMotor: facial muscle and&nbspsalivary gland

VIII Auditory nerve


Balance and hearing

IX Gloss pharyngeal


Sensory: tastingMotor: swallowing

X Vagus nerve


The main nerve of parasympathetic nervous systems

XI Accessory nerve


Swallowing and movement of head and shoulder

XII Hypoglossal nerve


Muscles of the tongue

Tableof the Cranial Nerves

TheSpinal Nervesare all mixed or are both sensory and motor neurons

TheAutonomic Nervous System consists of neurons in the CNS and otherbody parts or organs like lungs. Its role is to monitor conditionsinside the body and make necessary changes to them and its functionis always involuntary (Maximino, 2012). It is divided intosympatheticand parasympathetic nervous systems as shown in the table below:

Diagram4: a diagram on the functions of sympatheticand parasympathetic nervous systems

TheSympathetic Nervous System has preganglionic&nbspmotorneurons (shown in black) which originates from spinal cord intoganglia organized into two and runs parallel to and on both sides ofspinal cord (Titus, Revest &amp Shortland, 2007). Postganglionicreleases the noradrenalin neurons which stimulates the actions shownon the left site of the diagram.

TheParasympathetic Nervous System has vagusnerves which originate from the&nbspmedullaoblongata.Acetylcholine is a transmits produced by Postganglionicand the stimulation of The Parasympathetic Nervous System leads tochanges in the organs as in the right of the diagram above.


Thenervous system has several parts and each part needs to be knownincluding their function. Due to numerous parts, the patients cannotbe able to understand about hoe each part works and the effect of itwhen tampered with. This paper has simplified the interpretation ofthe nervous system and can be easily interpreted to affected patientsin a layman’s language.


Domburg,P. v. (1990). Humanbrainstem monoaminergic structures in Parkinson`s disease andAlzheimer`s disease: a neuroanatomical and morphometric analysis.Ermelo: [Drucker] Sonneheerdt.

Edelson,E. (1991). Thenervous system.New York: Chelsea House Publishers.

Maximino,C. (2012). Serotoninand anxiety neuroanatomical, pharmacological, and functional aspects.New York, NY: Springer.

Titus,A., Revest, P., &amp Shortland, P. (2007). Thenervous system.Edinburgh: Churchill Livingstone.