Third ventricle

The third ventricle is one of the four CSF-filled cavities that together comprise the ventricular system.

Gross anatomy

The third ventricle is a median cleft between the two thalami and is bounded laterally by them anteriorly and the hypothalamus and subthalamus posteriorly. Its anterior wall is formed by the lamina terminalis, columns of the fornix and the anterior commissure. Posteriorly it is bounded by the pineal gland and the habenular and posterior commissures. The roof is formed by the choroidal fissure and the bodies of the fornix.

There are two small anterior recesses and two small posterior recesses:

The third ventricle contains choroid plexus along its roof along the tela choroidea continuous with the choroid plexus from the lateral ventricles.

It communicates with the:

Variant anatomy

In some patients, the two thalami meet forming the interthalamic adhesion and when casts are made of the ventricular system, a hole is seen through the third ventricle.

Anatomy: Brain

Anatomy: Brain

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Article information

rID: 5780
Section: Anatomy
Tag: refs
Synonyms or Alternate Spellings:
  • 3rd ventricle

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Cases and figures

  • Figure 1: ventricular system
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  • Figure 2: IVH outlining the recesses of the third ventricle
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  • Figure 3: ventricles superimposed on lateral brain
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  • Figure 4: coronal brain through 3rd ventricle
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  • Figure 5: pineal region anatomy
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