lateral orbital sulcus

lateral orbital sulcus (los)

The term lateral orbital sulcus refers to a superficial feature identified by dissection on the ventral surface of the frontal lobe. In the human it constitutes the lateral leg of the H-shaped orbital sulci. It separates the lateral orbital gyrus from the (more medial) posterior orbital gyrus, which lies caudal to the transverse orbital sulcus. Rostral to the transverse orbital sulcus, it separates the lateral orbital gyrus from the (more lateral) orbital part of the inferior frontal gyrus ( Mai-1997 ). In the macaque it separates the lateral orbital gyrus from the fronto-orbital gyrus ( Martin-2000 ). Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).

Also known as: Sulcus orbitalis externus, lateral orbital sulcus, Sulcus orbitalis lateralis

NeuroNames ID: 81

All Names & Sources

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English

lateral orbital sulcus

Krieg-1975

Illustrations

Showing 5 illustration(s)

labeled line drawings of
sagittal section in
Macaca fascicularis

surface view of
all aspects in
macaque

drawing of
all aspects in
macaque

drawing of
lateral aspect in
macaque

diagrams of medial and
orbital prefrontal cortex in
human and macaque

Species With The Structure

Equivalent By	Human	Macaque	Rat	Mouse
Topology	Has The Structure	Has The Structure	Does Not Have The Structure	Does Not Have The Structure

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Basis

Has Equivalent

Organism

Their Name

Source

Topology

Yes

Homo sapiens (human)

Sulcus orbitalis lateralis

Mai-1997

Topology

Yes

Macaca mulatta (Macaca mulatta)

lateral orbital sulcus

Krieg-1975

Topology

Yes

Macaca mulatta (Macaca mulatta)

Sulcus orbitalis externus

Topology

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Topology

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Models Where It Appears

Structural CNS Model - Macaque

Brain structures of the macaque are illustrated in BrainInfo’s NeuroMaps macaque brain atlas. Structures are grouped by proximity in a hierarchy corresponding to the central nervous system hierarchy of NeuroNames ( Bowden-1995 Martin-2000 ). Structures in the NeuroMaps atlas are based on the segmentation of an MRI of the brain of a 3-year old male rhesus macaque (Macaca mulatta). The atlas is most useful for targeting structures for implantating electrodes and chemtrodes. Updated 29 Oct 2025.

brain

forebrain

cerebrum (endbrain)

cerebral cortex (cortical plate)