What Are Hormones?

Hormones are secreted by specialized cells of the internal secretion glands, also called endocrine glands, and have the function of modifying, slowing down or accelerating the functions of other cells, as well as stimulating or slowing down the production of other hormones.

They are chemical messengers that circulate through the blood or tissues; they can act in the whole organism, in a certain organ or within the same organ that secretes them.

There are two ways of receiving hormones. The first is through the cell membrane, mainly peptide or amino acid hormones, which are made up of protein chains. The second is intracellularly, which is the mechanism of the steroid or lipid hormones that cross the cell membrane by diffusion, and act on the internal organs of the cell.

Peptide hormones include:

Melatonin, which is responsible for inducing sleep.

Adrenaline (EPI), responsible for activating the fight or flight mechanisms: acceleration of the heart, increased supply of glucose to the brain and muscles, arrest of digestion.

Erythropoietin (EPO), which is responsible for regulating the production of red blood cells.

Insulin (INS), secreted in the pancreas by the Islets of Langerhans, ensures that the amount of glucose in the blood that circulates in the blood vessels, is constant and responds to the needs necessary to do any activity.

Oxytocin (OXT), which is responsible for stimulating the production of breast milk, confidence towards other human beings and regulates circadian rhythms.

Among the steroid hormones, the following stand out:

Testosterone: Responsible for increasing muscle mass, deepening the voice and developing masculine characters.

Estradiol: In charge of preparing the uterus for the implantation of the fetus; as well as the development of female secondary sexual characteristics.

Progesterone: Responsible for regulating and maintaining the changes produced in pregnancy.