Organ
Insula
Cortex concealed beneath the opercula
High-yield
The insula forms the deep cortical surface of the lateral sulcus. Most of its arteries arise from MCA M2 branches on that surface, with variable contributions from adjacent MCA segments.
Overview
The insula becomes visible when the frontal, parietal and temporal opercula are separated along the lateral sulcus. A surrounding sulcus marks much of its perimeter, and the central insular sulcus divides its short anterior gyri from the longer posterior gyri. Its connections link bodily sensation with emotional, autonomic and cognitive processing.
Reference facts
- Location
- Deep to the frontal, parietal and temporal opercula in the lateral sulcus
- Parts
- Usually three short anterior and two long posterior gyri, with additional variation; the limen insulae lies at the anteroinferior transition toward the basal region
- Blood supply
- Insular branches of the MCA, predominantly M2; some arise from M1 or M3. Small penetrating branches supply the cortex and adjacent white matter
- Relations
- From lateral to medial: insular cortex, extreme capsule, claustrum, external capsule and putamen
- Function
- Participates in taste, interoception, pain, autonomic responses, vestibular and auditory processing, and the integration of emotion with decisions
Clinical correlation
Loss of the normally distinct insular gray–white boundary on CT can be an early sign of MCA-territory ischemia. The sign reflects ischemic tissue change; it is not present in every early stroke and should be interpreted with the rest of the scan and clinical findings.
Frequently asked questions
Where is the insula located?
Deep to the frontal, parietal and temporal opercula in the lateral sulcus.
What does the insula do?
Participates in taste, interoception, pain, autonomic responses, vestibular and auditory processing, and the integration of emotion with decisions.
What are the parts of the insula?
Usually three short anterior and two long posterior gyri, with additional variation; the limen insulae lies at the anteroinferior transition toward the basal region.
What is the blood supply of the insula?
Insular branches of the MCA, predominantly M2; some arise from M1 or M3. Small penetrating branches supply the cortex and adjacent white matter.