Published: 10/02/2014 - Updated: 01/07/2018
Author: MSc. Miriam Reyes
The body is full of wonders, and one of them is the hypothalamus, an endocrine gland that has truly interesting functions. Not only does our equilibrium and the harmony of several bodily functions depend on it, but we can use them to develop mental abilities. These abilities aren’t unknown, but lie as hidden potential in every human being.
The word hypothalamus comes from the Greek word hipo-thalamos, which means underneath (Hipo) the chamber or house (Talamo). It is situated under the thalamus and one of its primary functions is to secrete hormones that act as inhibitors or stimulants for hormone secretions in the adenohypophysis. You could even say they work together in this.
This hormone is considered to be the integrating center of the vegetative nervous system which is also known as the autonomic nervous system, within the peripheral nervous system. This gland is also in charge of completing somatic-vegetative integrative functions. Together with the pituitary gland the hypothalamus creates bodily homeostasis by use of a negative feedback system.
Within its functions, the hypothalamus:
- Regulates vital rhythm and constants in the internal environment.
- Regulates appetite: this takes care of the hypothalamus Tuberal nuclei. When they are stimulated, we feel hunger. On the other hand, the ventral nuclei (of the Medial Posterio Hypothalamus area) inhibits appetite. When these nuclei are balanced between one another, we have a normal appetite. However, when one is damaged or when the ventral nuclei is not balanced in its functions, one will suffer from an increase in appetite which could end up as what is known as hypothalamic obesity. When the Tuberal nucleus does not function properly and is not balanced, a lack of appetite, or anorexia, is produced. We should point out that anorexia and obesity could stem from bad hypothalamic functioning, but this is not always the cause.
- Regulates body temperature which protects us from hypothermia or low body temperature from vasodilation. It increases sweating and decreases cardiac activity. It also protects us from hyperthermia or excessive body heat, by general vasoconstriction by secreting sweat and chills. If the first is injured, we are prone to hyperthermia. When the part of the hypothalamus that regulates this last function becomes injured, the individual will them frequently absorbe temperature from the environment, and will suffer from what is known as poikilothermism.
- Produces oxytocin: a hormone in men whose function is unknown, athough it is related to the external genitals and with the receptors in the seminal vesicle. In women, it is a hormone that contributes durin birth by provoking and accelerating the number of contactions. Afterwards it also influences the uterus to reposition itself after birth. Oxytocin also provoke the muscle fibers that surround the milk secretion cells in the mammary glands to secrete milk as a response to breastfeeding the child.
- Regulates water metabolism: in the hypothalamus, in the supraoptic nucleus, the antiduretic hormone is secreted which promotes the re-absorption of water on the level of distal portions of the renal tubules. When this part of the hypothalamus is damaged, it causes what is known as “insipid diabetes”. The secretion of this hormone is regulated according to the body’s water needs. The water needs are perceived by the hypothalamus thanks to its numerous capilaries contained in its nuclei, called osmoreceptors.
- Regulation of the respiratory functions: is in charge of regulating respiratory functions and vasodilation or vasoconstriction, cardiac and digestive functions, etc. For these functions, the hypothalamus is divided into the trophotropic hypothalamus which corresponds to the anterior hypothalamus. This part of the hypothalamus decreases vegetative activities and save unnecessary waste for the individual. The ergotrophic hypothalamus, which corresponds to the posterior hypothalamus, activates vegetative functions.
- Hormone regulator: in charge of releasing factors, either already released or suppressed, in the blood. It also produces neurohormones, ready for secretion.
- Regulates sleep: sleep and wake are two mechanisms that regulate the hypothalamus. When this is balanced, sleep is normally produced in the dark and during certain hours when the body needs rest.
- Regulates emotional mechanisms: neuronal discharges are received in the hypothalamus that cause emotional symptoms. Today, it is said that fear and primitive human instincts are regulated by this gland.
- Regulates the hypophysis: the hypothalamus regulates both the anterior lobe as well as the posterior lobe of the hypophosis. These two glands for a very important functional unity in the body.
Where is the hypothalamus located?
Under the thalamus, precisely in the middle of the brain between the two brain hemispheres (the left and the right).
Revised by: Dra. Loredana Lunadei on 01/07/2018
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