Glossary of anatomical terminology, definitions and abbreviations

This is a glossary of anatomical terminology, definitions and abbreviations pertinent to the description of the Central Nervous System.

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Anatomical localisation

The terms used for anatomical localisation are best understood if we think of an animal with a straight CNS, like a lizard. Here the terms "rostral", "caudal", "ventral" and "dorsal" mean respectively towards the rostrum, towards the tail, towards the belly and towards the back. In humans and other primates, the axis of the CNS is bent, and the face (the rostrum) is no longer at one end of the rostro-caudal axis. So, for the brain, "caudal" means towards the back of the head, "ventral" means towards the body, and "dorsal" means towards the top of the head.

It is common to represent the complex 3-D organisation of the CNS through slices, which is called the stereotactic approach (stereo from solid object and tactic from tactus, touch). The most common orientation for slices are Axial, a horizontal slice, Coronal, a vertical slice that can show both ears, and Parasagittal, a vertical slice that can show from the nose to the back of the head. A Sagittal slice is the slice that divides the head in two equal left and right sides. A Parasagittal slice is then any slice parallel to the Sagittal slice.

A

AC

Anterior Commissure.

Afferent

An afferent fibre is a fibre originating at the present point. For example a striatal afferent is an afferent originating at the striatum. See Efferent.

Anatomy

The determination of the regions in an organism that are to be considered its "parts". From the Latin anatomia, dissection, from the Greek, anatome, where ana means up, and temnein means to cut.

Annectent Gyrus

A small gyrus hidden in the depth of a sulcus. Also known as transition gyrus. See Gyrus, Sulcus.

Axial

A plane orthogonal to the superior-inferior axis. In the brain, it shows left and right, face and back of the head. Equivalent to Horizontal. See Anatomical localisation.

CalcS

Calcarine Sulcus.

Caudal

Towards the tail. See Anatomical localisation.

CC

Corpus Callosum.

CingS

Cingulate Sulcus.

Commissure

A groupe of fibres that cross the sagittal plane.

Contralateral

At the opposite side.

Coronal

A plane orthogonal to the anterior-posterior axis. In the brain, it shows left and right, the top of the head and the neck.

CS

Central Sulcus.

D

Dorsal

Towards the back (dorsum). See Anatomical localisation.

DTI

Diffusion tensor imaging.

DWI

Diffusion weighted imaging.

E

Efferent

An efferent fibre is a fibre that arrives at the present point. For example, a cortical efferent is a fibre coming from somewhere else, and arriving to the cortex. See also Afferent.

EPI

Echo planar imaging.

F

Fissure

A deep groove produced by opercularisation like the Sylvian fissure, or by the differentiation of the telencephalic vesicles like the Medial (Interhemispheric) Fissure.

Fundus

pl Fundi. The bottom of an inward fold. See Sulcal Fundus, Sulcus.

G

Gyral Crown

The top of a Gyrus. See Sulcal Wall, Sulcal Fundus, Gyrus, Sulcus.

Gyrus

pl. Gyri. An outward fold (a hill), as for example the gyri of the cerebellar or cerebral cortex. Important gyri are the precentral and postcentral gyri, for example.

H

Horizontal

A plane orthogonal to the superior-inferior axis. In the brain, it shows left and right, face and back of the head. Equivalent to Axial. See Anatomical localisation.

I

IFG

Inferior Frontal Gyrus.

IFS

Inferior Frontal Sulcus.

IPS

Intraparietal Sulcus.

Ipsilateral

At the same side. See Contralateral.

ITS

Inferior Temporal Sulcus.

J

K

L

Lacrimal Bone

A skull bone

M

Mesencephalic duct

aka Cerebral aqueduct or Aqueduct of Sylvius, is part of the liquidean system of the CNS.

Medial

At the middle. For example, the medial cortex is the cortex near the plane that divides left and right hemispheres;

Mesial

Directed towards the middle.

MRI

Magnetic Resonance Imaging.

N

O

Operculum

pl. Opercula.

oculo- eye

P

Parasagittal

A plane parallel to the sagittal plane (which divides left and right sides). See Sagittal, Anatomical localisation.

PC

Posterior Commissure.

postCS

Postcentral Sulcus.

preCS

Precentral Sulcus.

Pu

Putamen.

Q

R

Rostral

Towards the face. See Anatomical localisation.

S

Sagittal

A plane that divides exactly the left and right sides. See Parasagittal, Anatomical localisation.

SFS

Superior Frontal Sulcus.

STS

Superior Temporal Sulcus.

Sulcal Fundus

pl Sulcal Fundi. The bottom of an inward fold. See Sulcus.

Sulcal Wall

One of the two sides of a sulcus (an inward fold). See Sulcus.

Sulcus

pl. Sulci. An inward fold (a valley), as for example the central and calcarine sulci of the cerebral cortex. Examples of important sulci are the central sulcus (CS) and the calcarine sulcus (CalcS). See also Fissure.

T

Th

Thalamus.

Transition Gyrus

A small gyrus hidden in the depth of a sulcus. Also known as annectent gyrus. See Gyrus, Sulcus.

U

V

Ventral

Towards the belly. See Anatomical localisation.

W

X

Y

Z