The endocrine system is made up of glands that produce hormones. The body has eight major glands that regulate metabolism, growth, sleep, and reproduction. Hormones each have a unique purpose and act as the system’s chemical messengers. Here are five facts about the endocrine system:
1. The term “hormone” is only 100 years old.
In the 19th century, scientists started to realize that the organs in the body have a chemical communication system. They also learned that some disorders could be treated with endocrine tissues.
In 1902, two English physiologists discovered that chemicals in the body controlled pancreas secretions. This discovery sparked more research into the endocrine system throughout the 1900s, and the physiologists who made the first discovery later named the chemicals “hormones.”
2. Not all hormones are part of the endocrine system.
The endocrine system includes eight glands:
- Adrenal gland
- Thyroid gland
- Parathyroid gland
- Pituitary gland
- Pineal gland
- Reproductive glands
The body has some other organs that also secrete hormones, even though they’re not part of the endocrine system. For example, the stomach releases ghrelin, a hunger-related hormone, and gastrin, which causes the gastric gland to secrete gastric acid.
3. Stress has a big impact on the endocrine system.
When your body becomes stressed, the endocrine system will secrete high levels of certain hormones to make your body more energized and adaptable. For example, the pituitary-adrenal axis will release adrenaline, which increases the amount of blood your heart pumps out. During physical stress, the pituitary gland might increase the body’s secretion of growth hormone, which increases your metabolic activity.
Prolonged, intense stress can lead to endocrine disorders, including obesity, Graves’ disease, and gonadal dysfunction.
4. The endocrine system can be responsible for osteoporosis.
Osteoporosis occurs when the bones become less dense, which increases your risk of bone fractures. Almost one in 10 elderly adults in the U.S. have osteoporosis, and the endocrine system is sometimes at fault. Postmenopausal women can develop the condition because they have low levels of estrogen, a hormone that maintains bone mass.
Some other issues with the endocrine system can also cause osteoporosis. People with hyperthyroidism, or an overactive thyroid, sometimes develop the condition.
5. Plants don’t need an endocrine system to produce hormones.
Plants produce hormones that affect their growth, metabolism, cell division, and gene expression. However, they don’t have an endocrine system. Some agriculturalists have been using plant growth regulators, which are chemicals that act like hormones, to improve the growth of crops.