Endocrinology. Hormones. Nervous system. Learn about endocrinology and hormones in this article.
Nervous and endocrine system
When endocrinology only began to take shape as a separate branch of knowledge, the science of the nervous system was already well-developed. We thought that the central nervous system dominates the entire body, and controls hormones and endocrine reactions. But it is not the case. Nowadays, we know the nervous and endocrine systems are both responsible for transmitting information about changes in the external and internal environment, however, they do it differently.
The nervous and endocrine systems work together each other so that the body responds correctly to external influences. The high rate of nervous regulation is combined with a fast action of the nerve stimulus. Endocrine regulation on the other hand is more inertial: the system reacts slowly to changes in the external and internal environment, but these reactions last longer.
What are hormones?
Hormones are signalling compounds that enter the bloodstream and transmit information from organ to organ. If hormones are rapidly destroyed and act only within the tissue or organ in which they are formed, they are called paracrine. Such signalling compounds support the stable functioning of a tissue or organ: they regulate the number of cells, blood supply, and the ratio of pro-inflammatory and anti-inflammatory reactions.
There are fewer signal compounds in the body than other substances: to transmit information, many resources are not required. Hormones circulate in the blood at deficient concentrations. For each signalling compound, there are specific receptors that recognize individual hormones. Therefore, the specificity of recognition and the specificity of the reaction is very high.
Hormones in the fetus are involved in irreversible changes in the structure of various tissues. For example, androgens ensure the differentiation of the genital organs in embryos according to the male type. Without them, a pregnant woman will always have a girl. And in adulthood, all life processes – growth, development, reproduction and pregnancy – are also under the control of hormones.
Where are hormones produced?
Hormones are produced in the endocrine glands and “executive organs” (e.g the liver or heart).
The endocrine gland is a specialized organ. It consists of several types of cells, each of which produces its own hormone. The hormones of the endocrine glands react in a complex way to changes in the body. If the concentration of one changes, then the concentration of the other also changes.
Hormones that are produced in a certain organ regulate the processes associated with such organs. For example, hormones produced in adipose tissue regulate energy metabolism.
Endocrinology today
The notion that endocrinology is the science of the endocrine glands is long gone. Today it is generally accepted that endocrinology is the science of signalling compounds that are produced in various tissues and regulate important processes in the body. This is a strong support for the nervous system, the signals of which fade very quickly.
Citations:
“What Is Endocrinology? | Society for Endocrinology.” Endocrinology.org, 2019, www.endocrinology.org/about-us/what-is-endocrinology/.
“Endocrinology - Overview.” Mayo Clinic, 2019, www.mayoclinic.org/departments-centers/endocrinology/sections/overview/ovc-20392506.
Singla, Rajiv, and Sweta Singla. “Interventional Endocrinology: A Futuristic Perspective.” Indian Journal of Endocrinology and Metabolism, vol. 18, no. 3, 2014, p. 422, https://doi.org/10.4103/2230-8210.131221.
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