The Endocrine System

The Endocrine System

The endocrine system that is responsible for hormones production, transportation and organs regulation consists of glands that have specific functions. The hypothalamus and pituitary gland are an important part of hormones regulation controlled by a neural input. Hypothalamus links the nervous and endocrine systems through the pituitary gland (hypophysis).

The Hypothalamus

The hypothalamus is a small part of the brain located below the thalamus that consists of nuclei. It produces hormones that help to manage physiologic functions such as sleep, mood, hunger, temperature regulation, thirst, sex drive, mood and also a release of other hormones. It takes an important role in homeostasis maintenance (internal balance of the body). The hypothalamus activity influences on psychological behavior, growth, development and metabolism (Morgane, & Panksepp, 2015). Once cerebrum receives sings from different parts of the body about an unbalanced state, the hypothalamus releases the correct hormones into the circulatory system to stabilize the situation. Specialized neuron clusters that hypothalamus consists of produce Antidiuretic Hormone (ADH) and Oxytocin (OXT) that are transported to the pituitary gland where they are stored for later release. As recent research shows, the hypothalamus also controls many aspects of aging. It also gives hope that aging processes can be slowed down and longevity increased by changing signaling within the hypothalamus.

The Pituitary Gland

The pituitary gland (hypophysis) is an endocrine gland located at the base of the brain that has a size of a pea (0.018 oz.). It is composed of anterior, intermediate, and posterior lobes. The main function of the pituitary gland is to produce various hormones that regulate different aspects of human body and behavior. It has the direct influence on regulation and maintenance of body growth, blood pressure, temperature, water balance, metabolism, pain relief, thyroid gland function. The hypophysis also regulates sex organs functions (in both males and females), breast milk production in females and some aspects of pregnancy and childbirth. It is also important in mediating stress response (Melmet, 2011). All the functions of the hypophysis can be affected by under- or overproduction of specific hormones. The hypothalamus as part of the brain has neuroendocrine function and controls the pituitary gland by discharging or hindering hormones. It regulates hormones output of the anterior pituitary and also creates two hormones that are being transported to the posterior pituitary for storage and release.

Hormones Produced by the Pituitary Gland

Each part of pituitary gland produces different hormones. The anterior pituitary produces six hormones, four of them are tropic: Thyroid-stimulating hormone (TSH or thyrotropin; has an impact on thyroid gland and thyroid hormone production), Adrenocorticotropic hormone (ACTH or corticotrophin; has an impact on adrenal cortex and glucocorticoids production), Luteinizing hormone (LH; regulates steroid hormones production in gonads) and Follicle-stimulating hormone (FSH; regulates sperm production). Other two are Growth hormone (GH) that is an anabolic hormone responsible for skeletal and bones growth, fat mobilization, protein synthesis and Prolactin (PRL) that is responsible for milk production in females, pregnancy regulation and has an impact on sex hormones.

Other Hormones Produced by the Pituitary Gland

The intermediate pituitary produces Melanocyte–stimulating hormone (MSH), peptide hormone that regulates the release of melanin and influence on skin color and tan. The posterior pituitary stores and secretes 2 hormones: Antidiuretic hormone (ADH, or vasopressin) that regulates the tonicity of body fluids and causes the kidneys to reabsorb solute-free water, and Oxytocin that can create a positive feedback loop.

Hormones Produced by Other Endocrine Glands

There are various hormones produced by other endocrine glands that regulate human body processes. Thyroxine (T4) and some amount of Triiodothyronine (T3) are produced in the thyroid gland. They regulate the body’s metabolic rate, muscle control, bone density, brain development and digestive function. Calcitonin is also produced by the thyroid, but its functions are not yet known, most likely this hormone regulates calcium level in the body. Another hormone that controls calcium level in the blood and its transformation to bones is Parathyroid hormone that is being produced in Parathyroid glands. Insulin and glucagon are produced in the pancreas that are located in the upper abdomen and regulate the body’s blood sugar under control. Sex hormones such as estrogen and progesterone that help to facilitate conception and fertility are produced in ovaries; testosterone that is produced in testes regulates sperm production, muscle growth, secondary sexual characteristics development at puberty. Sex hormones are also produced in adrenal glands. Stress hormone cortisol is produced there as well (Rosenfeld, 2016).

Effects of Hypothalamus Dysfunction on the Pituitary Gland

When the hypothalamus stops to function properly, this effects on the pituitary gland functioning. But pituitary gland also controls adrenal glands, ovaries, testes and thyroid gland. That is why when hypothalamus is not working the right way, there are a lot of other body’s functions affected that are all vital to good health and mood.

Conclusion

Endocrine system has a key role in body processes and human behavior regulation. The collection of glands that endocrine system consists of produces various hormones that have a different impact on other body’s organs and systems. The hypothalamus links the endocrine and nervous systems by way of the pituitary gland and they have a significant influence on other body’s activities and states.

References

Melmed, Shlomo (2011). The Pituitary - (Third Edition). San Diego, CA 92101-4495, USA: Academic Press is an imprint of Elsevier. pp. 23–25. ISBN 978-0-12-380926-1.

Morgane, P. J., & Panksepp, J. (2015). Physiology of the hypothalamus. New York: M. Dekker.

Rosenfeld J. (2016). 7 Facts About Human Hormones and Their Functions. MentalFloss. Retrieved from http://mentalfloss.com/article/79588/7-facts-about-human-hormones-and-their-functions