Hypothalamus is a small cone-shaped structure in the brain that lies below the thalamus and above the pituitary gland, to which a stalk attaches it. It is approximately the size of a pea and accounts for less than 1% of the brain’s weight.
The brain receives signals from different systems and parts of the body, and they alert the Hypothalamus to any imbalances that need to be addressed. The Hypothalamus then responds by releasing the appropriate hormones into the circulation to balance the body.
It also coordinates the non-endocrine functions such as temperature regulation, regulation of the autonomic nervous system, and the control of appetite.
Parts of the Hypothalamus
The Hypothalamus is divided into three regions: anterior, middle and posterior. The nuclei of each part are distinct from the other. Nuclei are merely a group of neurons with vital functions.
The three regions are as follows:
01. Anterior region
Alternative name: The Supraoptic Region
Nuclei present in the region: The Supraoptic, Paraventricular nuclei, and other small nuclei.
Functions of Nuclei: Secretion of various hormones, regulating body temperature through sweat, and maintaining circadian rhythms (sleep-wake cycle).
02. Middle region
Alternative name: The Tuberal Region
Nuclei present in the region: The Arcuate and Ventromedial nucleus and a part of the Paraventricular nucleus.
Functions of Nuclei: It is associated with appetite, releasing growth hormone-releasing hormone (GHRH), which helps regulate growth.
03. Posterior region
Alternative name: The Mammillary Region
Nuclei present in the region: The Posterior Hypothalamus nuclei and The Mammillary nuclei.
Functions of Nuclei: To regulate the body temperature the posterior hypothalamic nucleus makes you shiver and inhibits sweat production. On the other hand, the mammillary nucleus controls the memory function.
Functions of Hypothalamus
The primary role of the Hypothalamus is to maintain homeostasis (balanced bodily state) at all times. The body always strives to achieve this balance, where the Hypothalamus works as a bridge between the nervous systems and endocrine system to achieve this state.
Hypothalamus also plays its part in many essential functions, such as:
- Maintaining the body temperature
- The urge of thirst
- Feeling hunger
- It also controls many emotions and sleep cycles
- Management of the sex drive
- Controlling blood pressure (BP) and also heart rate
- Production of some of the major digestive juices
- Also plays an important role in balancing the body fluids
Hormones of Hypothalamus
Hypothalamus produces many hormones, and most of these hormones are made in the anterior region.
Hormones produced by the anterior-hypothalamus:
- Corticotropin-releasing hormone (CRH): CRH and the pituitary gland and adrenal gland aids in metabolic and immune activity. In addition, it produces a hormone called adrenocorticotropic hormone (ACTH), which helps in both physical and emotional stress.
- Gonadotropin-releasing hormone (GnRH): The production of GnRH triggers the pituitary to produce many hormones associated with reproduction, such as follicle-stimulating hormone (FSH) and luteinising hormone (LH).
- Thyrotropin-releasing hormone (TRH): TRH stimulates the pituitary gland to generate thyroid-stimulating hormone (TSH), which is essential for the proper functioning of various body components, including the muscles, heart, and gastrointestinal tract.
- Somatostatin: This inhibitory hormone inhibits the pituitary gland from releasing some hormones like TSH.
- Oxytocin: This hormone regulates several essential behaviours and emotions, including sexual desire, recognition, and also trust, and it is also implicated in various reproductive system activities, such as birthing and breastfeeding.
- Vasopressin: This hormone is responsible for maintaining fluid balance. It’s also known as the antidiuretic hormone (ADH). It controls bodily water levels by directing the kidneys to absorb water.
Hormones produced by the middle region of the Hypothalamus:
- Growth Hormone Releasing Hormone (GHRH): It stimulates the pituitary gland to create growth hormones responsible for the body’s growth and development.
Hypothalamic Dysfunction
Hypothalamic dysfunction is a disorder with the hypothalamus. This condition can be a result of the following:
Common Causes of Hypothalamic Dysfunction:
- Surgery: Mainly brain surgeries that are performed near the midbrain.
- Radiation treatment to the brain.
- Brain injury or tumours may result in blood clots or stroke.
Some Other Causes:
- Anorexia: Emotional disorder, where appetite is lost.
- Rapid weight loss
- Pituitary apoplexy: Bleeding inside the gland.
- Aneurysm: Swelling of an artery.
- Subarachnoid haemorrhage
- Some immunological diseases
- Genetic disorders
The following measures can prevent dysfunction of the Hypothalamus:
- Eat a balanced diet: To reduce your risk of a hypothalamus condition, make sure you eat a balanced diet. For example, note the number of fats and sugars you consume.
- Get enough sleep: Researchers suggested that lack of sleep may increase the risk of neurological disease. Consider natural remedies for falling asleep and keeping your Hypothalamus healthy.
- Exercise regularly: If you can follow a proper diet, try doing exercise; even a mild amount of regular exercise is proven to reduce hypothalamic inflammation.
The Hypothalamus is the principal part of the brain, and usually, symptoms are unnoticed until it stops working. Following these tips can help to keep the Hypothalamus healthy.
Conclusion
The Hypothalamus maintains homeostasis by creating or controlling many hormones in the body. In addition, the Hypothalamus with the pituitary gland produces and transports other important hormones around the body. The hypothalamus and pituitary gland coordinate with other glands in the body’s endocrine system that creates different hormones. The hormone system works in a feedback loop that signals the Hypothalamus to stop releasing them. If that does not happen, the stimulating signals keep releasing the hormones, leading to excessive production of hormones and imbalance in the associated function.