Adenohypophysis and neurohypophysis: features and functions

The pituitary gland is a small gland, located in the Turkish silla, which is considered among the main ones in our body, since it is responsible for collecting messages that are directed towards the brain for the emission of signals and stimuli.

In addition, it produces and secretes differenthormonesthat are responsible for intervening in the biological functions of our body. The pituitary gland has two elements that are responsible for specific hormones in their functionality and they are adenohypophysis and neurohypophysis.

In the following article we will talk about the adenohypophysis and neurohypophysis, covering their main characteristics and functions.

What are the adenohypophysis and neurohypophysis?

They are elements belonging to the pituitary gland, which are responsible for regulating the segregation of certain hormones essential for the proper functionality of our body. They are the anterior and posterior lobes of the pituitary gland and are synthesis and secretion of hormones through nerve cells.

Adenohypophysis

It is an element of difficult access due to its location and is responsible for secreting six types of hormones, which are relevant for proper physiological functioning and are supplied through five different cells. In the adenohypophysis, there is the responsibility of gigantism produced in infants and acromegaly in adult individuals.

It plays an important endocrine regulating role and is under hypothalamic regulation through the nerves. It is worth mentioning that the adenohypophysis has pars tuberalis, pars distalis and pars intermedia (structures filled with colloidal material and constituted by cell layers).

Neurohypophysis

The neurohypophysis is located in the posteriorlobeand secretes two hormones responsible for synthesizing hypothalamic neurons. It is not responsible for producing but for segregating and storing them.

The hormones found in the neurohypophysis are oxytocin and vasopressin and are released through electrical stimulation by the hypothalamus.

Characteristics of the previous pituitary

The functionality of the adenohypophysis is evoked to certain characteristics, which will be mentioned below for the understanding of it and the recognition of its importance in our body.

It is known as the master gland.

Actually this denomination refers to the pituitary gland, but the anterior pituitary gland is the one that covers the importance of the hormones it secretes. Through them they manage to regulate many essential and vital functions in our body, which is why, together with its intrinsic relationship with thehypothalamus , it is a gland of great relevance.

It has an ovoid shape

Its structure is ovoid and it is located in the anterior part of the pituitary lobe, formed by epithelial cords and surrounded by what could be considered as a network of sinusoids, which are channels through which blood flows.

It is located below the hypothalamus

The pituitary gland is located at the base of the skull and is closely linked to the hypothalamus in orientation towards anatomical and functional activities. As we mentioned previously, the anterior pituitary gland is located in the anterior part of the lobe of the pituitary gland, which means that it is located below the hypothalamus.

Has glandular cells

The cells responsible for the secretion of hormones are of epithelial origin. Initially they were organized and differentiated through staining characteristics, but through the development of immunohistochemical techniques the following were identified:

• Somatotroph cells.
• lactotroph cells.
• corticotroph cells.
• Gonadotroph cells.
• thyrotroph cells.

Produces and releases trophic hormones

Among the hormones released by the adenohypophysis are trophic hormones or also recognized as stimulants, which within their functionalities highlights the ability they have to alter the functioning of glands such as endocrine ones.

They are also responsible for producing physiological responses through specific receptors in certain organs, and it produces a release of hormones to maintain feedback control of endocrine function.

It is regulated by the hypothalamus

In a scientific article on the Adenohypophysis , they mention the regulatory function through trophic hormones as its central function and that it is under hypothalamic regulation through neuropeptides.

Your injury or loss causes different disorders

Among the problems that can be unleashed in our organism, from the lesion of the adenohypophysis, growth arrest, atrophy of the testicles and ovaries, atrophy of the thyroid and failures or disorders in the metabolism of both lipids, carbohydrates and carbohydrates stand out. proteins.

Functions of the anterior pituitary

The adenohypophysis within its cells and hormones, is responsible for fulfilling functions in the body of great importance. They will be mentioned and described below.

Regulate endocrine function

With the previously mentioned regulation and secretion of trophic hormones, main endocrine functions are fulfilled by regulating them. In fact, the pituitary and adenohypophysis belong to this system, regulating glandularly.

Produce physiological responses

In the scientific article on Hypothalamus and adenohypophysis , it is quite clearly exposed how, being a gland that goes hand in hand with the activity of the hypothalamus, it regulates the coordination of physiological responses from different organs in our body, also integrating the signals received and stimulating appropriate responses.

Stimulate growth and physical development

Among the hormones present in those produced and secreted by the adenohypophysis is Growth hormone , that is, growth hormone, so that the regulation of growth and correct physical development of individuals is controlled by this functionality.

If any failure or alteration occurs in the pituitary gland, or directly in the adenohypophysis, problems of dwarfism, gigantism and altered development may occur in the individual with respect to their physical characteristics.

Regulate metabolism

Among the human physiology of the adenohypophysis we find the mediation of reactions in metabolismtag. regulating its development and also balances in the body such assodium and water, as well as inflammation and neuroendocrine reactions to stress.

Control the sensation of pain and pleasure

These functionalities are the responsibility of beta-endorphins, which are one of the hormones released through the adenohypophysis and they are associated with responses of moderation, inhibition of sensations of both pleasure and pain.

Generate milk production in the mammary glands

Prolactin is another of the hormones produced and regulated in the anterior pituitary gland, and closely related to the name given to them, they are responsible for generating milk production in the mammary glands after pregnancy, although regular levels are beginning to be seen. altered during the gestation process.

Intervene in the process of reproduction and sexual maturation

The correct physical development, growth and reproductive capacity has a lot to do with growth hormone. Although follicle-stimulating hormone and luteinizing hormone also have important roles in the correct sexual development of women and men, respectively.

They stimulate the production of testosterone and progesterone, as well as the formation of oocytes and sperm, which is why they are key to the reproductive processes.

Characteristics of the neurohypophysis

The hormones produced in the neurohypophysis through the capillary plexus lead to the identification of differences in functionality with the adenohypophysis.

It produces characteristic elements that structure it. These features will be mentioned below.

Makes up the posterior part of the pituitary gland

The location of the neurohypophysis takes place in the posterior lobe or neurohypophysis fabrica, which is also known as the pituitary gland.

Originates in the central nervous system

The location or embryological origin occurs in the Central Nervous System (CNS), due to its particular functions from the hormones that regulate and store. It has a close relationship due to the connection with the hypothalamus and its synthesis of nerve cells.

It is divided into three sectors

It is divided into three sectors or parts: median eminence, pars nervosa, and infundibulum. The pars nervosa is considered the most essential and functional.

The median eminence is responsible for the release of hypothalamic hormones and a probable sensory role. The pars nervosa is the major part of the neurohypophysis and is the storage site for the hormones oxytocin and vasopressin. Finally, the infundibulum, in charge of releasing them into the blood.

It is made up of pituitary cells.

The pituitary cells are located in the posterior lobe of the pituitary gland and their functionality is based on the secretion of oxytocin and vasopressin, so they clearly have a link in the structure of the neurohypophysis, who has this function as initial conceptualization. The pituitary cells are responsible for its correct functionality.

Stores substances in the hypothalamus

As we mentioned previously in the article, the neurohypophysis does not produce hormones, it is responsible for storing and later supplying them through the infundibulum.

The substances to which we refer, these being vasopressin and oxytocin, are synthesized in hypothalamic neurons and sent by the neurosecretory cells to the neurohypophysis for storage.

Stores and releases two important hormones

Those two are the ones that we have previously mentioned, which have quite key capacities for the proper functioning of our body. Oxytocin for its part is key to sexual reproduction, social life and postpartum.

Vasopressin allows the increase in vascular resistance and increase in blood pressure, in addition to being linked to the individual’s capacity for social behavior, their sexual life and relationships with other people.

Alterations in its functioning produce different disorders

The alteration of the production of neurohypophysis, be it excess or defect, has the risk of developing certain disorders in the individual. Among them, for example, the excessive secretion of vasopressin, or also known as diuretic hormone, would generate gastrointestinal, respiratory and even neurological effects.

Functions of the neurohypophysis

Although they have been previously mentioned, we now emphasize more on the functions that the neurohypophysis covers in our organism and where its activity is directed.

release oxytocin and vasopressin

The neurohypophysis is not a producer, but a storage, regulating and releasing substance such as oxytocin and vasopressin in our body.

Intervene in sexual reproduction

Mainly oxytocin, it is the one that has a fundamental role in the intervention of reproduction, since it influences erections and induces sensations of the need for physical contact.

stimulate lactation

The Breastfeeding process begins with the nervous stimulus, the message is processed by the hypothalamus and the response is sent to the neurohypophysis, where the signal proceeds to produce galactogenesis and oxytocin, the secretion of milk with prolactin.

Stimulate uterine contraction

Oxytocin is also responsible for this functionality, due to its ability to produce rhythmic contractions at normal levels. That is why we previously mentioned its importance in the birth process, since it is essential for cervical dilation.

Intervene in behavior and social relationships

As we have been mentioning both hormones, both oxytocin and vasopressin have effects in the body that allow us to improve the sensation of pleasure when having interpersonal relationships, they even produce stimuli through neurotransmitters and also work as enhancers in the creation of bonds.