Diencephalon and Thalamic Structures

Part of the brain responsible for regulating vital functions like body temperature, hunger, thirst, sleep, and emotion. It is located below and in front of the thalamus.

The largest part of the diencephalon, it acts as a relay station for sensory information, connecting various regions of the brain to the cerebral cortex.

A part of the thalamus that receives auditory (sound) information from the lower brainstem and relays it to the auditory cortex.

A part of the thalamus that receives visual information from the optic tract and projects it to the visual cortex.

A group of thalamic nuclei involved in relaying sensory information from the body to the somatosensory cortex.

A group of thalamic nuclei involved in relaying motor information from the basal ganglia to the motor cortex.

A group of thalamic nuclei involved in relaying information from the mamillary bodies to the cingulate cortex.

A group of thalamic nuclei involved in relaying information to the frontal cortex.

The diencephalon is the part of the brain located above the brainstem and below the cerebrum.

A part of the thalamus that extends over the medial and lateral geniculate bodies, involved in complex sensory and motor processing.

The supraoptic, suprachiasmatic, and paraventricular nuclei are located in the supraoptic portion of the hypothalamus. The tuberal portion contains the infundibular nucleus, which connects to the pituitary gland. The mammillary portion contains the mammillary nuclei, which are important for memory.

The fornix carries fibers from the hippocampus to the mamillary bodies. The prefrontal cortex sends emotional inputs. Visceral information, such as heart rate and digestion, is relayed from the vagal sensory nuclei. Information from the genitalia and nipples also reaches the hypothalamus.

The hypothalamohypophyseal tract connects the supraoptic and paraventricular nuclei to the posterior pituitary. This tract releases hormones like oxytocin and vasopressin. The portal hypophyseal system carries hormones from the hypothalamus to the anterior pituitary, which controls the release of other hormones throughout the body.

The hypothalamospinal tract originates in the hypothalamus and projects down the spinal cord. The posterolateral and dorsomedial areas of the hypothalamus control sympathetic activity, which involves fight-or-flight responses. The anterior area controls parasympathetic activity, which manages rest-and-digest functions.

The subthalamus is located between the dorsal thalamus and the tegmentum of the midbrain. It receives fibers from the globus pallidus, a part of the basal ganglia that helps regulate movement.

The subthalamus plays a crucial role in controlling movement and is involved in Parkinson's disease, a neurological disorder that affects movement.

The habenula is a pair of small structures located on each side of the third ventricle, in front of the superior colliculus. It plays a role in reward and aversion, and its dysfunction might be linked to addiction.

The pineal gland, also called the pineal body, is located behind the habenula. It secretes melatonin, a hormone that regulates sleep-wake cycles.

The habenular trigones are two small structures located on each side of the third ventricle. They are involved in processing sensory information and communicating with the limbic system. The habenular trigones work alongside the pineal gland and are thought to influence emotional responses.

The epithalamus is comprised of the habenular trigones and the pineal gland. The epithalamus controls the release of melatonin and also plays a role in regulating emotional responses.