The hypothalamus is department of a brain which received the name thanks to the fact that it is located below a thalamus, that is "visual hillocks". It is not outlined not accurately therefore is considered as part of a neural network. Already long time this department weighing only 5 grams is exposed numerous research that is connected with a huge number of the functions which are carried out by it.

It is possible to call a hypothalamus the main center which is responsible for regulation of internal environment.

The hypothalamus is also called a hypothalamus. It is located before brain legs in consists of the following structures: olfactory and visual parts. The hypothalamus including the centers of a vegetative nervous system concerns to the first.

At a hypothalamus there are neurosecretory cages and neurons of usual type. They make mediators and proteinaceous secrets, at the same time in neurosecretory cells there is a process of proteinaceous synthesis, and neurosecretion is allocated in blood and a lymph of an organism. Transformation of nervous impulse in hormonal happens thanking these cells.

Control of activity of endocrine system is made by a hypothalamus thanks to the fact that vasopressin and oxytocin (i.e. neurohormones) cosecretes its neurons. In other words, in spite of the fact that the mass of a hypothalamus does not exceed 5% of mass of a brain, it completely controls endocrine system of an organism. Together with a hypophysis the hypothalamus forms the general complex in which the first plays effector, and the last — regulating a role.

The neurons perceiving everything changes which happen in a spinal cord and blood (content of hormones, structure, temperatures) also lie in a hypothalamus. Bark of a great brain, cardiovascular system, a respiratory center and limbic system are also connected with a hypothalamus.

In a hypothalamus there are following centers:

Centers of hunger and thirst. As a result of damage of kernels of a hypothalamus bulimia – uncontrollable desire to absorb food that can lead to obesity can develop. Activation of neurons creates food motivation.

Dream and wakefulness. The hypothalamus plays an important role in these processes, was established by clinical tests that a lethargical sleep (the motionless disease state similar to a dream) and a narcolepsy (insuperable drowsiness) come at disturbances of this department of a brain. Its back part plays a crucial role in wakefulness, average – for a long dream.

Emotions and behavior. Communication of a hypothalamus with other departments of a brain generalizut excitement. Some departments lead to braking and suppress emotions, some create "imaginary rage", etc.
The reactions of a hypothalamus arising as the response to changes of internal signs are adjusted by bark of a great brain. Many specialists agree in opinion that this part of a brain controls even such reactions of an organism which are considered as instinctive: sexual, food, defensive.

Disturbances of activity of a hypothalamus at the person it is practically always connected with tumoral, and also inflammatory or traumatic damages. Such damages can be the general or limited, for example occupying one of areas (front, intermediate or back). Anyway, disturbance leads activity of a hypothalamus to very serious functional frustration which nature is defined by degree and duration of defeat of a hypothalamus.