The endocrine system has glands that secrete the hormones. They are specific because each hormone elicits a response in a particular target organ or cell group rather than throughout the body.
Exocrine hormones are secreted into the bloodstream by channels. They usually affect distant organs and tissues. Endocrine hormones are secreted into tissues (not tubes). They enter the bloodstream through capillaries.
To understand How Are Hormones Secreted In The Body, let’s discuss them in detail.
Main Types of Hormones
- Amines are simple molecules
- Proteins and peptides made from amino acid chains
- Cholesterol-derived steroids
Glands
Hormones are released by glands directly into the bloodstream. They include a feedback mechanism that maintains the proper balance of hormones. In this way, they prevent the over-secretion of hormones. Low levels of hormones often cause glandular secretions.
When hormone levels in the blood rise, glandular secretion can stop until hormone levels decrease again. This feedback process, which is characteristic of most glands, triggers a cycle of hormone secretion. When hormones perform their function in the target organ/tissue, they are destroyed. They are destroyed by the actual tissue of the liver or target organ. Then they are eliminated by the kidneys.
Different types of Glands and Hormones secreted by them
Pituitary Glands
There are two different glands in the pituitary glands, the anterior lobe, and the posterior lobe. It is the “master gland” because it controls all other glands in the endocrine system. The size of the pituitary gland is no larger than small peas.
The anterior pituitary gland causes the secretion of six essential hormones.
- ACTH (Adrenocorticotropic hormone) stimulates the adrenal glands to secrete hormones.
- HGH (Human Growth Hormone) is involved in the growth.
- TSH (thyroid-stimulating hormone) Stimulates the thyroid glands to secrete thyroid hormones.
- FSH (Follicle Stimulating Hormone) Stimulates the production of female eggs or male sperm.
- PRL (prolactin) Causes the corpus luteum (the area around the adult follicle) to produce estrogen and progesterone.
- LH (Luteinizing Hormone) Works with FSH to induce ovulation and prepare the uterus for pregnancy. In men, cause testicles release testosterone.
The posterior pituitary gland stores and releases hormones. They are secreted by the hypothalamus of the brain, including:
- ADH (antidiuretic hormone) stimulates smooth muscle, blood vessels, and intestines.
- OT (oxytocin) stimulates the smooth muscles of the uterus during pregnancy. It causes the uterus to contract during labor. It also enables the milk (duct) of the breast.
Thyroid Gland
The thyroid gland secretes 3 significant hormones:
Thyroxine(tetraiodothyronine)
Consists of iodine, which is essential for the body’s average growth and metabolism.
Triiodothyronine
It has the same function as thyroxine
Calcitonin
Lowers blood calcium levels.
Parathyroid Glands
Four small, rounded parathyroid glands are usually placed in two pairs, above and below the thyroid gland. Parathyroid hormone raises blood levels of calcium and phosphorus.
Pancreatic Glands
The pancreas is a long, narrow lobular gland behind the abdomen. There are two types of cells in the pancreas: exocrine cells and endocrine cells.
- Exocrine cells secrete pancreatic juice. It is used in the duodenum as an essential part of the digestive system.
- Endocrine cells are grouped throughout the pancreas, known as the islets of Langerhans.
There are three types of endocrine cells:
- Alpha cells that secrete glucagon
- Beta cells that secrete insulin
- Delta cells that block glucagon and insulin secretion:
Adrenal glands
The adrenal gland is a combination of two glands, the adrenal cortex, and the adrenal medulla.
Adrenal Cortex
The anterior pituitary gland controls the adrenal cortex by secreting the hormone ACTH. All secretions in the adrenal cortex are known as steroids. The adrenal cortex is associated with three classes of hormones.
Mineralocorticoids
The most important of which is aldosterone. Produced by the outer layers of the adrenal cortex. Aldosterone promotes sodium (Na) retention and potassium (K) excretion.
Glucocorticoids
The mid cortex produces glucocorticoids. It affects nearly all cells in the body that regulate fats, proteins, and carbohydrates.
Gonadal hormones
They are made by the inner cortex and secrete two hormones, androgen (male) and estrogen (female). The adrenal glands are not the only glands that secrete sex hormones.
Adrenal Medulla
The inner part of the adrenal gland is the adrenal medulla. Secreted hormones affect the structure of the body under the control of the sympathetic nervous system. Release two hormones, i.e., Adrenaline and Non-Adrenaline. Both are related to high Blood Pressure, Increased heart rate, and increased glucose level.
Gonads
It produces hormones that are important for the development and function of the reproductive organs. The gonads are made up of female ovaries and male testes. They are controlled by the pituitary gland and produce secondary sexual characteristics.
- Testosterone is a male hormone. It causes secondary sexual characteristics in men after puberty. Men with low T levels can benefit from natural testosterone supplements to get their testosterone levels to where they should be.
- The adrenal cortex and ovaries secrete estrogen. It is present in the blood of all women from puberty to menopause.
- Progesterone works in the uterus to prepare the fertilized egg for implantation. It causes the development of the breast. It is essential for the full development of the maternal proportion of the placenta.
This was all about the hormones and their secretion. You should consult an Endocrinologist regularly to make sure that your body is working perfectly.
Frequently Asked Questions (FAQs)
How are hormones generated and secreted?
The pituitary gland feels elevated hormone levels and tells other glands to stop producing and releasing hormones. When hormone levels fall below a certain point, the pituitary gland may indicate other glands to make more and release more.
How many hormones are produced by the body?
Over 50 hormones have been identified in humans and other vertebrates.
What’s the reason for Hormonal Imbalances?
The leading causes of hormonal imbalances are thyroid problems, stress, and eating disorders.
What are the significant symptoms of hormonal imbalance?
Symptoms include irregular menstruation, decreased libido, unexplained weight gain, and mood swings.
