Nervous system

Midbrain

The midbrain (mesencephalon), unlike other parts of the brain, is less complex. It has a roof and legs. The cavity of the midbrain is the cerebral aqueduct.

The diencephalon is not visible on a whole brain preparation, as it is entirely hidden under the cerebral hemispheres. Only on the base of the cerebrum can the central part of the diencephalon, the hypothalamus, be seen.

Third (III) ventricle

The third (III) ventricle (ventriculus tertius) occupies a central position in the diencephalon. The ventricular cavity has the appearance of a sagittally located narrow slit, limited by 6 walls: two lateral, superior, inferior, anterior and posterior.

Hypothalamus

The hypothalamus forms the lower sections of the diencephalon and participates in the formation of the floor of the third ventricle. The hypothalamus includes the optic chiasm, the optic tract, the gray tubercle with the funnel, and the mammillary bodies.

Thalamus, metathalamus and epithalamus

The thalamus (thalamus dorsalis; syn.: posterior thalamus, thalamus) is a paired formation, having a shape close to ovoid, located on both sides of the third ventricle.

Frontal lobes of the brain

In the anterior part of each hemisphere of the brain is the frontal lobe (lobus frontalis). It ends in front with the frontal pole and is bounded below by the lateral groove (sulcus lateralis; Sylvian groove), and behind by the deep central groove.

The parietal lobe of the brain

Behind the central sulcus is the parietal lobe (lobus parietalis). The posterior border of this lobe is the parieto-occipital sulcus (sulcus parietooccipitalis). This sulcus is located on the medial surface of the cerebral hemisphere, deeply dissects the upper edge of the hemisphere and passes to its upper lateral surface.

Occipital lobe of the brain

The occipital lobe (lobus occipitalis) is located behind the parieto-occipital groove and its conditional continuation on the upper lateral surface of the hemisphere. Compared to other lobes, it is small in size.

Temporal lobe of the brain

The temporal lobe (lobus temporalis) occupies the lower lateral parts of the hemisphere and is separated from the frontal and parietal lobes by a deep lateral groove. The edge of the temporal lobe, covering the insular lobe, is called the temporal operculum (operculum temporale).

Lateral ventricle

The lateral ventricle (ventriculus lateralis) is located in the thickness of the cerebral hemisphere. There are two lateral ventricles: the left (first), corresponding to the left hemisphere, and the right (second), located in the right hemisphere of the cerebrum.

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