Interthalamic adhesion

Brain: Interthalamic adhesion
Dissection showing the ventricles of the brain. (Interthalamic adhesion labeled as Massa Intermedia at center right.)
Coronal section of brain through intermediate mass of third ventricle.
Latin	adhesio interthalamica
Part of	thalamus
NeuroNames	hier-284

The medial surface of the thalamus constitutes the upper part of the lateral wall of the third ventricle, and is connected to the corresponding surface of the opposite thalamus by a flattened gray band, the Interthalamic adhesion (massa intermedia, middle commissure, gray commissure).

In non-human mammals it is a large structure. In humans this mass averages about 1 cm in length in its antero-posterior diameter. It sometimes consists of two parts and occasionally is absent. The interthalamic adhesion is found in 70-80% of humans. It is present more often in females and larger than in males by an average of 53 percent. [1].When absent in development, no noticeable deficit has been observed.

It contains nerve cells and nerve fibers; a few of the latter may cross the middle line, but most of them pass toward the middle line and then curve lateralward on the same side.

Additional images

Thalamus

Human brain left dissected midsagittal view

External links

• Atlas of anatomy at UMich n1a8p6
• Image at Harvard University
• Diagram at csuchico.edu (labeled as Massa intermedia)
• Roche Lexicon - illustrated navigator, at Elsevier 13048.000-3

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.

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