The hypothalamus

Hypothalamus:
It is the inferiormost division of the diencephalon, subserves functions of three systems:
1. The autonomic nervous system,
2. The endocrine system, and
3. The limbic system.
The hypothalamus helps to maintain homeostasis.
Major Hypothalamic Nuclei and Their Functions
1. The suprachiasmatic nucleus receives direct input from the retina. It plays a role in the regulation of
circadian rhythms.
2. The anterior nucleus plays a role in temperature regulation. It stimulates the parasympathetic
nervous system. Destruction results in hyperthermia.
3. The paraventricular nucleus synthesizes antidiuretic hormone (ADH), oxytocin, and corticotropinreleasing
hormone. It gives rise to the supraopticohypophyseal tract, which projects to the
neurohypophysis. It regulates water balance (conservation) and projects directly to the autonomic
nuclei of the brain stem and all levels of the spinal cord. Destruction results in diabetes insipidus.
4. The supraoptic nucleus synthesizes ADH and oxytocin (similar to the paraventricular nucleus).
5. The dorsomedial nucleus, when stimulated in animals, results in savage behavior.
6. The ventromedial nucleus is considered a satiety center. When stimulated, it inhibits the urge to eat.
Bilateral destruction results in hyperphagia, obesity, and savage behavior.
7. The posterior hypothalamic nucleus plays a role in thermal regulation (i.e., conservation and
increased production of heat). Lesions result in poikilothermia (i.e., inability to thermoregulate).
8. The lateral hypothalamic nucleus induces eating when stimulated. Lesions cause anorexia and
starvation.
Thalamus
It is the largest division of the diencephalon. It plays an important role in the integration of the sensory
and motor systems.
Major Thalamic Nuclei and Their Connections

Regards,
Vivek Shivani