Neuroendocrine system: parts, functions and characteristics

Our body is a complex organism, which is made up of various systems of organs, tissues, enzymes and fluids which allow us to fulfill certain biological functions which allow us to survive.

However, the correct operation of all these systems requires the existence of others that allow managing and coordinating them. The first and most relevant is the nervous system, in charge of precisely such management and control. But it is also necessary that elements are generated that allow the systems to be activated or inhibited by the orders of the nervous system. The latter would be the case of the endocrine system.

And since the emission of these substances requires some control at the neural level, we can also speak of a neuroendocrine system that allows to control the emission of substances such as hormones, necessary for the proper functioning of various body systems. And it is about the latter that we are going to talk throughout this article.

• Related article: "Parts of the Nervous System: anatomical structures and functions"

Neuroendocrine system: what is it?

We can consider the neuroendocrine system to be set of structures that make up the endocrine system and part of the brain dedicated to the emission, control and transmission of the substances they generate.

It is a vital system for the human being, which is responsible for the emission and management of hormones and which as such influences the generation of changes in the operation or even the structure of our Body. These hormones travel primarily through the cardiovascular system towards the organs and tissues on which they must act.

In general, we can consider that this system originates in the hypothalamus and from it, passing through the pituitary, it can generate different circuits or pathways.

Among them, three stand out: the hypothalamus-pituitary-adrenal (which regulates especially the body's response to the environment as well as stress and activation), hypothalamus-pituitary-gonadal (focused on maturation and sexual development) and hypothalamus-pituitary-thyroid (more linked to body regulation and increase).

Features

Although at a general level the function of this system is to generate and manage production and transmission of hormones, this fact actually causes the neuroendocrine system to have a large amount of subfunctions.

In this sense, among many other elements, it allows us to contribute to manage our immune system, regulate our sexual response, generate hunger or thirst in order to act when our body needs nutrients, experience emotions and feelings towards elements of the environment or towards other people, regulate digestion, control biological rhythms, maintain the electrolyte balance of our Body. or even cause our growth and development during the life cycle.

Main parts of the neuroendocrine system

The endocrine system is made up of a large number of various hormone-producing glands, which are managed by the nervous system, jointly configuring the system neuroendocrine. Among the main components of this last system we can find the following elements.

1. Hypothalamus

The main nucleus of the nervous system that is responsible for regulating the entire neuroendocrine system, the part of the system with the greatest role in controlling and coordinating its functioning and the release of hormones, is the hypothalamus.

This part of the brain initiates the production of different hormones that in turn activate the pituitary, another of the main elements of the system. Different circuits also arise from it, which include the pituitary gland and are aimed at regulating different systems.

The hypothalamus produces different hormones, among which the oxytocin and vasopressin, as well as hormones that release other substances that allow them to be synthesized in the hypothalamus

2. Hypophysis

The pituitary o pituitary gland is another of the main elements of the neuroendocrine system, and it is in it specifically that the Most of the hormones that from the brain and through the blood are going to be sent to other areas and organs of the organism. It is connected and attached to the hypothalamus by neurons and blood vessels, in fact hanging from it.

Although the hypothalamus is rather part of the nervous system, the pituitary is halfway between it and the endocrine system, acting as the main nucleus that allows orders from the nervous system to be sent to the rest of the endocrine glands of the body.

Likewise, it is configured by the anterior pituitary or adenohypophysis and posterior pituitary or neurohypophysis. In the adenohypophysis, important hormones such as growth hormones, ACTH, luteinizing, beta-endorphins, prolactin or thyroid stimulating hormone are generated. It is responsible for the release of trophic hormones, which are those that will activate other endocrine glands in the body.

The neurohypophysis, despite being linked to hormones such as oxytocin or vasopressin, does not actually synthesize hormones: its main function is to store and later release these substances into the blood, which the hypothalamus produces.

3. Epiphysis

Sometimes forgotten and sometimes confused with the pituitary, epiphysis or pineal gland is a gland located in the brain which is of great relevance to us, since it participates in the emission of substances such as melatonin and therefore in the maintenance of biological rhythms (such as sleep / wakefulness).

It is also linked to the production of endorphins and has relevance at the level of helping to manage our emotional sphere, or the production of melatonin.

4. Thyroid

The thyroid gland is one of the main glands of the endocrine system. Located in the throat, specifically over the trachea and under the pharynx, the thyroid is the organ that generates, among others, thyroid hormone and thyroxine, which are essential in metabolism and participate in the growth of the body.

It also affects the body's temperature, the functioning of the nervous and cardiovascular systems, and the management of body energy.

5. Parathyroid glands

Generally little known, this grouping of four glands is located behind the thyroid and its main function is that of maintain a balance or homeostasis in the calcium levels present in our body (both at the blood and bone levels, for example).

6. Scam

The thymus is a part of the endocrine system that is often unfairly forgotten, but it has a fundamental role for our survival: it is responsible for producing T lymphocytes, an essential part of our system immune. It is located just behind the breastbone.

7. Kidney glands

Located above the kidneys and divisible into cortex and medulla, these glands are a fundamental part of the generation of hormones such as corticosteroids or in the production of substances essential for growth (including part of the sexual characteristics), the management of carbohydrates, the regulation of elements such as sodium or potassium, the activation of the body or the preparation for the fight-flight.

In them, for example, adrenaline, cortisol or angiotensin are generated.

• You may be interested: "Adrenaline, the hormone that activates us"

8. Pancreas

Part of the digestive system, it is the main producer of insulin and glucagon, fundamental elements for the management, use and storage of glucose extracted from food. A) Yes, is essential for blood glucose management and therefore a relevant element in metabolism.

It also secretes somatostatin, which helps slow growth by stopping the secretion of growth hormone from the pituitary gland.

9. Testicles / Ovaries

The testes and ovaries are also part of the endocrine and neuroendocrine systems, and they involve one of the main sources of sex hormones in our body. The testes primarily produce testosterone, while the ovaries produce progesterone and the ovaries. estrogens.

These hormones affect sexual behavior, contribute to the formation of secondary sexual characteristics specific to each sex and have to do with aspects such as desire, preparation for childbirth, strengthening and growth of bones and muscles or even socio-emotional elements (in both sexes) beyond what reproductive.

Some diseases that affect it

As with other systems, the neuroendocrine system or some of its components can be affected by some type of condition.

Examples of this can be found for example in the Mellitus diabetes (the most common of all diseases linked to the endocrine system, which has even potential fatal if not controlled), in which the cells of the pancreas that secrete insulin are altered, or hyper or hypothyroidism, in which the production of hormones by the thyroid is excessively increased or decreased in such a way that it generates various problems.

Also different neoplasms or tumors can cause problems in the different pathways that make up the neuroendocrine system. Other problems that Cushing's syndrome or Addison's syndrome may appear, linked to excess / deficit of cortisol, gigantism or dwarfism, hirsutism, growth arrest or alterations of the physical development.

In short, there are many problems that can derive from a malfunction of the neuroendocrine system and that can have physical, mental or behavioral consequences, to the point of being able to suppose a risk for the survival. It is essential to further investigate this system in order to be able to solve problems that may already exist or prevent them from appearing.

Bibliographic references:

• Gómez, M.; Espejo-Saavedra, J.M. and Travillo, B. (2012). Psychobiology. CEDE PIR Preparation Manual, 12. CEDE: Madrid
• Kandel, E.R.; Schwartz, J.H. & Jessell, T.M. (2001). Principles of neuroscience. Fourth edition. McGraw-Hill Interamericana. Madrid.