Occupies only 1% of brain's volume.
Its lumen is diocoel or III ventricle.
Roof is epithalamus.
On it pineal body is present.
Floor is hypothelamus. It has optic chiasma.
Here on it infundibulum, pituitary gland & corpus mammary are present.
Diocoel is attached to 4th ventricle by Iter or aqua duct of sylvius.
1. Help to cerebrum to control voluntary actions.
2. To control feeling of cold, hot & pain.
3. Hunger centre.
4. Thermoregulatory centre.
5. To control sweatening, thrusting, sleeping & fatigueness.
6. Emotions as love / hate/ revange.
7. Water balance & blood pressure.
8. To control sexual desire.