All the mental processes that take place from the human nervous system do not depend only on the activity of the neurons.

Among the parts of the brain, there are several whose activity depends directly on what is happening in the endocrine system, that is, the set of organs that secrete hormones.

The pituitary gland (or hypophysis) is precisely one of the structures in our brain where bridges the gap between the world of hormones and the world of nerve impulses that run through our neurons. Thanks to the pituitary, what we think and perceive through the senses has an impact on the way we enter one or another emotional state.

What is the pituitary gland?

The pituitary is an endocrine gland that helps us to make all those hormonal responses that occur in the body well coordinated with each other and keep us in a state of harmony in relation to what happens in the environment.

The pituitary gland is one of the areas where orders to produce certain hormones are rapidly transmitted when certain stimuli are detected in the environment . For example, if we see a snake, this visual information, before reaching the areas of the cerebral cortex in charge of converting this signal into something that can be thought of in abstract terms, passes through a region called the thalamus.

The thalamus processes this visual information and, by detecting information patterns that relate this data to the hazard, transmits a signal that will quickly pass to the pituitary gland, located very close, and this will start to secrete hormones related to the use of force, speed of reaction and strength . These hormones will navigate through the bloodstream and activate other glands throughout the body , thus bringing the whole body into a certain activation situation for several minutes.

All this, without waiting for the cerebral cortex to have processed the visual information and the reasoning that the snakes are poisonous.

The pituitary gland and the limbic system

The example we have just seen is a sample of the way in which the pituitary converts nerve signals into hormone production that remain for several seconds floating in the bloodstream. While each “action” of a neuron lasts for thousandths of a second, the hormonal effects of the pituitary gland are longer lasting , although their effects are also less precise.

While the neurons connect only to some, and not all, other nerve cells, the hormones are left to navigate in the blood without control, activating areas of the body far away from each other, and in a wider time frame. That is why, once we have finished running, not only does it cost us more to breathe for the next few seconds or minutes, but our way of thinking is also altered; it is a side effect of the hormones, something that is not useful to us but happens anyway due to the wide temporal range of the endocrine system.

The Pituitary and Descartes

The pituitary gland is one of the most focused parts of the brain. In fact, it’s located just below the hypothalamus, another structure that makes up the limbic system.

It is partly for this reason that the famous philosopher Rene Descartes identified it as the possible place where, according to his dualistic perspective, the soul (res cogitans) interacts with the matter of the human body (res extensa). Of course, this theory is rejected by the scientific community , since it does not really provide an explanation about the functioning of the pituitary gland.


The pituitary gland is an example that psychological processes are totally linked to hormonal processes and therefore also to the emotional side of our personality .

It is important to bear this in mind, as it reminds us to what extent rationality and irrationality are not two watertight compartments, and also that there are certain automatic emotional responses that do not depend on our way of reflecting on what is happening to us.