With so many major and minor endocrine glands, it is not surprising that several dozen different hormones are produced in the body every day. Some glands produce only one or two hormones, while others can make over a dozen.
There are two major types of hormones, those made from amino acids (like proteins) and those made from cholesterol. Some hormones are made by modifying a single amino-acid, for example serotonin, melatonin, epinephrine, and thyroid.
Cholesterol-based hormones are also known as steroid hormones. These include sex hormones (testosterone, estrogen, and progesterone), cortisol, aldosterone and many others. The name ‘steroid’ comes from the unique chemical structure of a cholesterol molecule, which contains four rings (sterol of cholesterol) and a side chain.
The pituitary regulates and controls most of the other endocrine glands. Some pituitary hormones increase or decrease the activity of the thyroid, adrenals, testes, and ovaries. Others have a direct effect on certain tissues of the body.
The thyroid gland is located in the front of the neck. Thyroid gland produces thyroxin, also known as thyroid hormone. Thyroid hormone controls the overall metabolism of the cells, energy production, cellular growth and development.
The parathyroid gland is actually a group of four glands located in the neck, near the thyroid gland. They produce parathyroid hormones, which regulates calcium concentration in the blood, promoting calcium release from the bones, increasing absorption of dietary calcium in the intestine, and promoting calcium conservation in the kidneys.
The pancreas is primarily known as the organ that produces a digestive enzyme that participates in the breakdown of food. However, it also functions as an endocrine gland that makes two hormones- insulin and glucagon. Both of them participate in the regulation of the glucose (sugar) level in the blood.
Both males and females have two adrenal glands located on top of the kidneys. Despite their small size, the adrenals manage to produce many different hormones that have a profound effect on a number of body functions. Aldosterone, which regulates water balance by affecting the amount of water excreted and reabsorbed by the kidneys, is one of the main hormones produced by the adrenal glands. Known as the ‘stress’ hormone, cortisol supports the utilization of nutrients by the cells during stress and reduces inflammation. Epinephrine and norepinephrine increase heart and pulse rate, heart output, blood pressure, respiratory rate, and overall metabolic rate. Dehydroepiandrosterone (DHEA) improves utilization of glucose, immune system function, and cardiovascular performance. In addition, adrenals produce progesterone, pregnenolone, androstenedione, and many other hormones.
The pineal gland makes melatonin, a hormone that tells the organs to switch to a night-time mode of activity. It is also a potent anti-oxidant. Melatonin is used as a supplement to help improve sleep quality and to minimize the effects of jet lag.
Testis are male endocrine organs that produce testosterone, which is responsible for the development of sexual characteristics, libido, muscle mass, bone strength, immune system, and other functions. Even though testosterone is called a ‘male sex hormone’ it is also present in small amounts in women and supports the same functions as in men.
Ovaries are not necessary a gland, but they are responsible for the release of hormones into the female body. Aside from releasing storing eggs, they produce progesterone and estrogens, which are responsible for maintaining a normal menstrual cycle and a number of other functions. All of the glands have an important part in keeping the body healthy by producing hormones that help the body function properly. Some are more susceptible to malfunctioning or under producing hormones than others. Occasionally, hormones are the culprits behind certain unexplained changes in our bodies that affect weight, libido, or sleep patterns. If you are concerned about your health, you should seek medical advice from your physician.