Question

Describe briefly the diencephalon of humans.

Answer 1

Hint: The human brain is subdivided by many classification systems. One particular nomenclature refers to the duality of the brain is diencephalon. It's the caudal part of the forebrain (prosencephalon) that occupies the central region of the brain.

Complete answer:
The diencephalon is comprised of the:
1.Epithalamus
2.Thalamus
3.Subthalamus
4.Metathalamus
5.Hypothalamus

Each of the components of the diencephalon has specialized functions that are integral to life. The diencephalon acts as a primary relay and processing center for sensory information and autonomic control. The communicating pathways between these structures and other parts of the body makes the diencephalon a functionally diverse area. A number of these connections include pathways to the limbic brain (seat of memory and emotion), basal ganglia (motor coordination), also as primary sensory areas, like auditory or visual.

Forebrain (prosencephalon) region of the developing vertebrate brain includes telencephalon, which contains the cerebral hemispheres, and, under these, the diencephalon that consists of thalamus, hypothalamus, epithalamus, subthalamus. The forebrain plays a central role within the processing of data associated with complex cognitive activities, sensory and associative functions, and voluntary motor activities. It represents one among the three major developmental divisions of the brain; the opposite two are the midbrain and hindbrain.

The cerebral hemispheres conjure the uppermost portion of the brain and are involved in sensory integration, control of voluntary movement, and better intellectual functions, like speech and logical thinking. The thalamus is that the main relay centre between the neural structure and also the cerebrum; the hypothalamus is a vital control centre for drive, pleasure, pain, hunger, thirst, force per unit area, blood heat, and other visceral functions. The hypothalamus produces hormones that control the secretions of the ductless gland gland, and it also produces oxytocin and hormone, which are stored in and released by the posterior pituitary gland gland.

Functions of primary diencephalon structures: The thalamus could be a quite switchboard of data, believed to act as a relay between a spread of subcortical areas and therefore the pallium. Thalamus also plays a crucial role in regulating states of sleep and wakefulness. Thalamic nuclei have strong reciprocal connections with the cortex, forming thalamo-cortico-thalamic circuits that are believed to be committed consciousness. The thalamus plays a serious role in regulating arousal, awareness level, and activity. Damage to the thalamus can cause permanent coma.

The subthalamus connects to the basal ganglia, a basal nucleus of the telencephalon. It receives afferent connections from the neural structure and striatum and regulates muscle movements.
Hypothalamus performs numerous functions most of which relate directly or indirectly to the regulation of visceral activities by way of other brain regions. It synthesizes and secretes neurohormones called hypothalamic-releasing hormones which stimulate or inhibit secretion of pituitary hormones. Hypothalamus controls temperature, hunger, thirst, fatigue, sleep, and circadian cycles.

The epithalamus functions as a connection between the visceral brain and other parts of the brain. Some functions of its components include the secretion of melatonin by the epiphysis cerebri (involved in circadian rhythms) and regulation of motor pathways and emotions.

Note: Diencephalic (Russell’s) syndrome: It should be noted that a lesion (vascular or neoplastic) of any a part of the diencephalon may lead to a deficit within the function related to that component. For instance, the supraoptic nucleus of the hypothalamus can impair the assembly and subsequent release of vasopressin. Diencephalic (Russell’s) syndrome is characterized by:
1.Severe emaciation with normal caloric intake
2.Euphoria
3.Locomotor hyperactivity
4.Non-anaemic pallor
5.Hypotension
6.Hypoglycaemia