| Orbital part of inferior frontal gyrus | |
|---|---|
 Orbital part of inferior frontal gyrus labelled 3. | |
 Lateral surface of cerebral cortex | |
| Details | |
| Identifiers | |
| Latin | pars orbitalis gyri frontalis inferioris |
| NeuroNames | 2410 |
| NeuroLex ID | birnlex_1207 |
| TA | A14.1.09.114 |
| FMA | 61982 |
| Anatomical terms of neuroanatomy | |
The orbital part of inferior frontal gyrus also known as the pars orbitalis is the orbital part of the inferior frontal gyrus. [1]
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. Anatomical term created by Gerard of Cremona. “Orbit” can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 millilitres, of which the eye occupies 6.5 ml. The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and nasolacrimal duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.
The inferior frontal gyrus(IFG), (gyrus frontalis inferior), is the lowest positioned gyrus of the frontal gyri, of the frontal lobe, and is part of the prefrontal cortex.
Contents
In humans, this region is bordered by the triangular part of the inferior frontal gyrus (pars triangularis) and, surrounding the anterior horizontal limb of the lateral sulcus, a portion of the opercular part of inferior frontal gyrus (pars opercularis). Bounded caudally by the anterior ascending limb of the lateral sulcus, it borders on the insula in the depth of the lateral sulcus. It is bordered anteriorly/inferiorly by the lateral orbital sulcus. [2] [3]
The lateral sulcus is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe. The insular cortex lies deep within the lateral sulcus.
Cytoarchitectonically it is most closely represented by Brodmann area 47 (BA47). [4] However, BA47 and pars orbitalis are not synonymous, as pars orbitalis specifically refers to a grossly visible gyral region and BA47 refers to the cytoarchitectonic features of brain tissue. In vivo neuroscience research almost exclusively discusses the gyral region, although the gyral and cytoarchitectonic terms are frequently used synonymously.
Cytoarchitecture, also known as cytoarchitectonics, is the study of the cellular composition of the central nervous system's tissues under the microscope. Cytoarchitectonics is one of the ways to parse the brain, by obtaining sections of the brain using a microtome and staining them with chemical agents which reveal where different neurons are located.
Brodmann area 47, or BA47, is part of the frontal cortex in the human brain. Curving from the lateral surface of the frontal lobe into the ventral (orbital) frontal cortex. It is below areas BA10 and BA45, and beside BA11. This cytoarchitectonic region most closely corresponds to the gyral region the orbital part of inferior frontal gyrus, although these regions are not equivalent. Pars orbitalis is not based on cytoarchitectonic distinctions, and rather is defined according to gross anatomical landmarks. Despite a clear distinction, these two terms are often used liberally in peer-reviewed research journals.
In neuroanatomy, a gyrus is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci. Gyri and sulci create the folded appearance of the brain in humans and other mammals.
