Anatomical terms of neuroanatomy

Terms are often derived from Latin and Greek, and like other areas of anatomy are generally standardised based on internationally accepted lexicons such as Terminologia Anatomica.

To help with consistency, humans and other species are assumed when described to be in standard anatomical position, with the body standing erect and facing observer, arms at sides, palms forward.

In humans and many other primates the axis of the central nervous system is not straight, but bent to allow for forward vision when the body is vertical.

For example, to describe the human brain, "rostral" still means "towards the beak or snout (Latin rostrum)", or at any rate, the interior of the cranial cavity just behind the face.

"Caudal" means "towards the tail (Latin cauda"), but not "towards the back of the cranial cavity", which is "posterior" (behind, in ordinary motion).

The rostro-caudal axis of the human central nervous system (magenta in the diagram) makes a near 90° bend at the level of the midbrain and continues through the brain-stem and spinal cord.

"Superior" and "inferior" are adjectives from human anatomy, respectively meaning towards to top of the head or the soles of the feet when standing.

A decussation (from Latin decussis 'ten', written as a capital X) refers to nerve fibers that cross the sagittal plane from one side of the central nervous system to the other, and connect different brain regions.

The second type is thought to be due to an axial twist, such that each hemisphere of the forebrain represents predominantly the contralateral side of the body.

The anatomical axes of orientation of the human brain are at odds with the anatomical axes of the human body in the standard anatomical position.
Red axis shows how the head bent forward as the back pointed upwards:
c: Caudal
r: Rostral
Yellow axes show the conventions for naming directions in the brain itself:
c: Caudal (though not tail direction),
d: Dorsal
r: Rostral (effectively unchanged)
v: Ventral (though not belly direction)
Anatomical axes, planes and localisations in the human brain. Three axes:
  • d: Axial, Superior-inferior or Dorsoventral axis (yellow)
  • l: Left-right, or Lateral axis (cyan, blue-green)
  • m: Median, Antero-posterior or Rostral-to-caudal axis (magenta)
Three major planes:
  • A: Axial (blue), containing the lateral axis and also the Medial axis
  • C: Coronal plane (green), containing the axial axis and the lateral axis
  • S: Sagittal plane (red), containing the axial axis and the medial axis
Also:
  • e: The eye at the anterior end of the brain
  • P: A Parasagittal plane (yellow) through one eye; parasagittal planes comprise the class of planes parallel to (and therefore lateral to) the sagittal plane.
Image of the human brain showing sulci , gyri , and fundi shown in a Coronal section .