Anatomical
planes
The brain can be dissected for study in several
ways:
A medial cut or section divides the brain into right and left halves of equal size, separating the right and left hemispheres from one another.
A sagittal cut runs parallel to the medial cut, but divides the brain into right and left portions of unequal size. A medial section may be considered to be a type of sagittal cut. However, a sagittal section may not be a type of medial cut.
A coronal cut runs from ear to ear, separating the brain into front and back portions.
Horizontal (equal halves) or transverse cuts are perpendicular to coronal, medial, and sagittal cuts. They divide the brain into upper and lower sections.
When describing the nervous system, anatomists use the terms anterior and posterior to indicate front and back.
Superior and inferior can be used to refer to the upper and lower parts of the nervous system.
Cranial and cephalic can be used as synonyms for superior.
Rostral, which means "toward the beak," is also sometimes substituted for superior.
The antonym for rostral is caudal, a term that means "toward the tail," and may be used to replace inferior in descriptions of the brain and spinal cord.
Ventral means "toward the belly" and dorsal means "toward the back." Structures in the lower part of the brain may be described as ventral.
Medial is toward the center and lateral toward the sides.
The neuraxis or central nervous system consists of the brain and spinal cord
The brain is made up of the cerebral cortex , sub cortical structures, brain stem, and cerebellum.
.
The spinal cord consists of grey and white matter surrounded by meninges in which cerebro-spinal fluid circulates. It runs from just below the medulla to the small of the back. Below that the cauda equina (projections) from the spinal cord goes down to the coccygeal area.
Peripheral Nervous System Includes the Somatic and Autonomic Divisions
Cranial and Spinal Nerves are Part of the Somatic Division
There are twelve pairs of cranial nerves. Their motor components are called lower motor neurons
Ten of them have their cell bodies in the brain stem.
Some are motor; some are sensory, and some are both motor and sensory.
Six of them are involved in speech and swallowing.
They connect the central nervous system to the body.
There are thirty-one pairs each of which is both sensory and motor.
Autonomic Nervous System
Although controlled by the hypothalamus the hypothalamus is not part of it. It is involved in all glandular functions.
It works with the the endocrine system for control of hormonal secretions.
Sympathetic and Parasympathetic Divisions
The sympathetic prepares the body for flight or fight.
The parasympathetic helps, among other things, to bring the body back to normal.