Question

Explain the functions of the major hormones of the endocrine system. (Please name all of them) ?

Answer 1

The Hypothalamus Essentials

The portion of the brain that maintains the body’s internal balance (homeostasis).

The hypothalamus is the link between the endocrine and nervous systems.

The hypothalamus produces releasing and inhibiting hormones, which stop and start the production of other hormones throughout the body.

The hypothalamus plays a significant role in the endocrine system. It is responsible for maintaining your body’s internal balance, which is known as homeostasis. To do this, the hypothalamus helps stimulate or inhibit many of your body’s key processes, including:

• Heart rate and blood pressure

• Body temperature

• Fluid and electrolyte balance, including thirst
• Appetite and body weight
• Glandular secretions of the stomach and intestines
• Production of substances that influence the pituitary gland to release hormones
• Sleep cycles

The hypothalamus is involved in many functions of the autonomic nervous system, as it receives information from nearly all parts of the nervous system. As such, it is considered the link between the nervous system and the endocrine system.

Hormones of the Pituitary Gland

The hormones of the pituitary gland send signals to other endocrine glands to stimulate or inhibit their own hormone production. For example, the anterior pituitary lobe will release adrenocorticotropic hormone (ACTH) to stimulate cortisol production in the adrenal glands when you’re stressed.

 

The anterior lobe releases hormones upon receiving releasing or inhibiting hormones from the hypothalamus. These hypothalamic hormones tell the anterior lobe whether to release more of a specific hormone or stop production of the hormone.

Hormones of the Thyroid

The two main hormones the thyroid produces and releases are T3 (tri-iodothyronine) and T4 (thyroxine). A thyroid that is functioning normally produces approximately 80% T4 and about 20% T3, though T3 is the stronger of the pair.

 

To a lesser extent, the thyroid also produces calcitonin, which helps control blood calcium levels.

Parathyroid Hormone

Parathyroid hormone (PTH) has a very powerful influence on the cells of your bones by causing them to release their calcium into the bloodstream.  

• PTH regulates how much calcium is absorbed from your diet, how much calcium is excreted by your kidneys, and how much calcium is stored in your bones.  
• We store many  pounds of calcium in our bones, and it is readily available to the rest of the body at the request of the parathyroid glands.
• PTH increases the formation of active vitamin D, and it is active vitamin D that increases intestinal calcium and phosphorus absorption.

Hormones of the Pancreas

The production of pancreatic hormones, including insulin, somatostatin, gastrin, and glucagon, play an important role in maintaining sugar and salt balance in our bodies.

 

Primary hormones secreted by the pancreas include:

• Gastrin: This hormone aids digestion by stimulating certain cells in the stomach to produce acid.
• Glucagon: Glucagon helps insulin maintain normal blood glucose by working in the opposite way of insulin. It stimulates your cells to release glucose, and this raises your blood glucose levels.
• Insulin: This hormone regulates blood glucose by allowing many of your body’s cells to absorb and use glucose. In turn, this drops blood glucose levels.
• Somatostatin: When levels of other pancreatic hormones, such as insulin and glucagon, get too high, somatostatin is secreted to maintain a balance of glucose and/or salt in the blood.
• Vasoactive intestinal peptide (VIP): This hormone helps control water secretion and absorption from the intestines by stimulating the intestinal cells to release water and salts into the intestines.

Hormones of the Ovaries

Ovaries produce and release two groups of sex hormones—progesterone and estrogen. There are actually three major estrogens, known as estradiol, estrone, and estriol. These substances work together to promote the healthy development of female sex characteristics during puberty and to ensure fertility.

 

Estrogen (estradiol, specifically) is instrumental in breast development, fat distribution in the hips, legs, and breasts, and the development of reproductive organs.

 

To a lesser extent, the ovaries release the hormone relaxin prior to giving birth. Another minor hormone is inhibin, which is important for signaling to the pituitary to inhibit follicle-stimulating hormone secretion.