Hypothalamus: what it is, characteristics and functions in the organism

Is there anything as fascinating as the human mind? Probably not. Neuroscience is the science that studies the nervous system and the human brain.

It covers all sorts of things, such as human behavior, neurodegenerative diseases, and even brain evolution.

However, neuroscience is a relatively new science, and therefore, there is still much to learn about our brains.

Anyway, scientists have revealed many secrets about various parts of our brain, such as the hypothalamus.

Therefore, we invite you to know a little more about the hypothalamus, what it is, what it is for and much more, in the following article.

What is the hypothalamus?

The hypothalamus is located on the lower surface of the brain. It is located just below the thalamus and above the pituitary gland, to which it is attached by a stalk.

It is an extremely complex part of the brain that contains many regions with highly specialized functions.

In humans, the hypothalamus is about the size of a pea and accounts for less than 1% of the brain’s weight.

One of the main functions of the hypothalamus is to maintain homeostasis, that is, to keep the human body in a stable and constant condition.

Similarly, the hypothalamus responds to a variety of signals from the internal and external environment, including body temperature, hunger, feeling full. After eating, blood pressure and hormone levels in the circulation.

It also responds to stress and controls our daily bodily rhythms, such as the nightly secretion of melatonin from the pineal gland and changes in cortisol (the stress hormone) and body temperature over a 24-hour period.

Additionally, the hypothalamus collects and combines this information and makes changes to correct any imbalances.

Main structures of the hypothalamus

In a studypublished in IntechOpen, the main parts of the hypothalamus were analyzed, which is made up of structures called the nucleus, and each of them has a different function. In this sense we tell you part by part:

Arched nucleus

This section of the brain, known as the arcuate nucleus, is a collection of neurons found in the hypothalamus. Some neurons contain dopamine that inhibits the release of the hormone prolactin by the pituitary gland.

When activated, these neurons can produce marked increases in appetite that result in obesity. These neurons may be regulated by glucose, insulin, and leptin.

Previous hypothalamic nucleus

This region is responsible for heat loss through sweating. The main function of this region is thermoregulation, which is the ability of the organism to modify its temperature within certain limits, even when the temperature is quite close to the target.

Posterior hypothalamic nucleus

This region works in conjunction with the anterior hypothalamic nucleus, only instead of taking care of heat loss to regulate temperature, it takes care of maintaining heat when it’s cold.

Side Cores

The hypothalamus is mainly composed of different nuclei. According to Science Direct , it plays a central role in the control of energy balance and in the regulation of eating behaviors.

It also receives multiple sensory regions that affect taste and other olfactory areas.

Nipple Core

The mammillary nuclei are a pair of small round bodies, located on the lower surface of the brain that are part of the limbic system.

According to Stat Pearls, the main function of the mammillary bodies is memory recollection, which begins within the hippocampus. Theta waves activate neurons in the hippocampus and thus information is transmitted to the mammillary bodies.

Features of the hypothalamus

Despite its minuscule size, the hypothalamus plays an essential role in many important functions of the body. Its name comes from the ancient Greek ὑπό: which means “below” and θάλαμος: which means “chamber”.

The hypothalamus is a part of the brain filled with small nuclei with a variety of functions. One of the most important is to communicate the nervous system with the endocrine system through the pituitary gland.

Here we point out the most notable characteristics of this brain organ:

It is part of the limbic system

The forebrain is the most anterior division of the brain and contains the most complex networks of the central nervous system.

The forebrain has two main divisions: the diencephalon and the telencephalon. The diencephalon is lower and contains the thalamus and hypothalamus (which together make up the limbic system).

Handles core processes

The hypothalamus has a variety of fundamental functions. Many of the important functions of the hypothalamus are known as the two H’s: homeostasis and hormones.

Since the hypothalamus is responsible for regulating homeostasis in the body, that is, maintaining the stability of the body. And on the other hand, it is responsible for regulating hormones.

Located near the brainstem

The hypothalamus is located on the lower surface of the brain. It is located just below the thalamus and above the pituitary gland and brain stem.

It is an extremely complex part of the brain containing many regions with highly important functions.

Acts as a bridge between the brain and the endocrine system

It could be said that the hypothalamus is the intermediary of the brain and the endocrine system, since it is the link between the endocrine and nervous systems.

The endocrine system is a network of glands throughout the body that regulate certain bodily functions, such as body temperature, metabolism, growth, and sexual development.

Responsible for homeostasis

The hypothalamus also plays an important role in the endocrine system. It is responsible for maintaining the internal balance of your body, which is known as homeostasis.

To do this, the hypothalamus helps stimulate or inhibit many of your body’s key processes like heart rate and blood pressure.

Functions of the hypothalamus

The hypothalamus is responsible for carrying out many functions necessary to keep our body healthy and stable.

Here are some of the most important functions carried out by the hypothalamus in our body.

Regulates blood pressure

According to a study published by the NHS, the UK’s national health service, the hypothalamus regulates blood pressure, as well as heart rate.

This is because one of the main functions is to maintain homeostasis in the body, so one of the tasks to maintain balance in our body is to control blood pressure depending on the situation and when and where we need more or less pressure.

Body temperature control

According to a study published by InfoMed Health, the internal temperature of our body is regulated by the hypothalamus.

The hypothalamus makes sure that our temperature stays at about 37°C. If our temperature is too low, the hypothalamus will make sure that the body generates and maintains heat.

In the same way, if our temperature is very high, send the signal so that we sweat, which will help us regulate the temperature and lower it.

Controls muscle tension

The hypothalamus, among other organs, influences the nervous system, which involves involuntary activities of the organs.

It also mediates activity in the pituitary gland, which releases hormones into the bloodstream. This means that under stress, muscles tighten, breathing becomes faster and deeper.

Control hunger

In a study published by the Endocrinology and Metabolism Clinics of North America, it was discovered that hunger, cravings, and hedonic sensations are also controlled by homeostatic processes, generated by the hypothalamus.

In this way, the hypothalamus controls cravings and hunger by sending signals to the brain to produce certain hormones that cause hunger and cravings, such as ghrelin, leptin, and insulin.

Regulates sleep

For the same reasons that we mentioned above, the hypothalamus is in charge of regulating absolutely all the necessary functions for the organism.

Among them is sleep. In the same way that the hypothalamus sends the signal to the brain to secrete hormones of all kinds, it is also responsible for generating hormones that induce sleep, such as serotonin.

Regulates thirst and urine production

Early on, they discovered that the body’s main “thirst center” in the brain is the hypothalamus.

Special sensors in the hypothalamus constantly monitor the concentration of sodium and other substances in the blood. And that’s why it also has the task of regulating urine to regulate sodium levels in the body.

In addition, there are two sets of nerve cells in the hypothalamus that produce hormones.

A set sends the hormones they produce through the pituitary stem to the posterior lobe of the pituitary gland, where these hormones are released directly into the bloodstream. One of them is antidiuretic hormone that stimulates the reabsorption of water in the kidneys.

Control emotions and moods

A study published by IBRO Reports found that the hypothalamus is also in charge of our emotions and mood, which it regulates by sending signals to secrete certain mood-regulating hormones, such as dopamine.

In addition to controlling emotional responses, the hypothalamus is also involved in sexual responses, the release of hormones, and the regulation of body temperature.

Controls the release of hormones

There is a set of hormones that are produced through the pituitary gland, where these hormones are released into the bloodstream, such as oxytocin, the love hormone, which rather fulfills the function of stimulating the contraction of the uterus during childbirth and is important during lactation.

On the other hand, the hypothalamus works as the central computer that sends the orders of what hormones are needed.

In this sense, the hypothalamus releases stimulating and inhibitory hormones such as those of the thyroid gland and the adrenal cortex, as well as growth hormone and prolactin, for milk production.

Therefore, the hormones produced in the hypothalamus are corticotropin-releasing hormone, dopamine, and growth hormone.

Controls uterine contractions

As we have seen before, the hypothalamus plays an essential role during childbirth.

Since it is in charge of secreting the oxytocin hormone, which although it is a hormone known as the love hormone, since it secretes after sex and serves to form affective bonds.

This hormone is also secreted during childbirth, as it helps with uterine contractions that help carry out a delivery.

Contributes to memory regulation

The hypothalamus plays a fundamental role in both short-term and long-term memory formation. This is because the hypothalamus is responsible for producing the happiness hormone, dopamine.

Although the dopamine hormone is referred to as the happiness hormone because it makes us happy and puts us in a good mood, it is also important to mention that dopamine is a necessary hormone to keep us motivated.

This is why when it comes to forming new memories or learning a new topic it is necessary to maintain curiosity and motivation along the way, and for that we need the help of dopamine.

Controls sexual arousal

The hypothalamus influences sexual behavior. Stimulates the pituitary gland to release sex hormones.

When the levels of these hormones drop, so does the sexual desire. Thus, feedback control of gonadal hormone production occurs.

Regulates available energy levels

The hypothalamus is one of the best-studied and most important brain regions involved in the central control of eating and energy expenditure.

In fact, the arcuate nucleus within the hypothalamus is considered to be critical for the regulation of eating and metabolism.