Hormones Of The Endocrine Glands - Types and There Target Organ and it's Function :

Endocrine glands are special organs in the body that produce and release hormones directly into the bloodstream. These hormones act as chemical messengers, traveling throughout the body to regulate various processes such as growth, metabolism, reproduction, and stress response, helping to maintain overall balance and coordination of body functions.

1. The Hypothalamus

It is a small area of the brain that plays a crucial role in regulating various physiological functions by controlling the release of hormones from the pituitary gland. The hormones produced by the hypothalamus are referred to as "hypothalamic releasing hormones" and "hypothalamic inhibiting hormones." These hormones travel through the bloodstream to the anterior pituitary gland, where they stimulate or inhibit the release of specific hormones. Here are the major hypothalamic hormones and their target organs:

(a). Growth Hormone-Releasing Hormone (GHRH) :

(b). Growth Hormone-Inhibiting Hormone (GHIH) :

(c). Prolactin-Releasing Hormone (PRH)

(d). Prolactin-Inhibiting Hormone (PIH), also known as Dopamine:

(e). Melanocytes Releasing Hormone (MRH) :

(f). Melanocytes Inhibiting Hormone (MIH) :

(g). TSH-Releasing Hormone (TSHRH) :

(h). Corticotropin-Releasing Hormone (CRH) :

(I). Gonadotropin-Releasing Hormone (GnRH) :

(g). Adrenotropic Releasing Hormones (ARH) :

2. The pituitary gland

It also known as the "master gland," is a small, pea-sized gland located at the base of the brain. It is divided into two main parts: the anterior pituitary gland (adenohypophysis) and the posterior pituitary gland (neurohypophysis). Each part of the pituitary gland produces and releases different hormones:

A. Anterior Pituitary Gland :

The hormones produced by the anterior pituitary gland are often regulated by releasing hormones from the hypothalamus. These releasing hormones travel through blood vessels to the anterior pituitary.

(a).Growth Hormone (GH) : Promotes growth and development of tissues and organs, and plays a role in regulating metabolism.

(b). Prolactin (PRL) : Stimulates milk production in the mammary glands after childbirth.

(c). Thyroid-Stimulating Hormone (TSH) : Stimulates the thyroid gland to produce thyroid hormones (T3 and T4), which regulate metabolism, energy production, and growth.

(d). Adrenocorticotropic Hormone (ACTH) : Stimulates the adrenal glands (specifically the adrenal cortex) to produce cortisol, a stress hormone that helps regulate metabolism and the body's response to stress.

(e). Follicle-Stimulating Hormone (FSH) : In females, it stimulates the growth of ovarian follicles and helps regulate the menstrual cycle. In males, it plays a role in sperm production.

(g). Luteinizing Hormone (LH) : In females, it triggers ovulation and promotes the production of progesterone. In males, it stimulates the production of testosterone.

B. Posterior Pituitary Gland :

Unlike the anterior pituitary, the posterior pituitary gland does not produce its own hormones. Instead, it stores and releases hormones that are synthesized in the hypothalamus. These hormones are transported along nerve fibers from the hypothalamus to the posterior pituitary.

(a). Antidiuretic Hormone (ADH), also known as Vasopressin: Regulates water balance by promoting water reabsorption in the kidneys, reducing urine output, and helping to maintain proper blood volume and blood pressure.

(b). Oxytocin, Love Hormones , plays a role in childbirth by stimulating uterine contractions during labor. It also helps with milk ejection during breastfeeding and plays a role in social bonding and emotional behaviors.

3. Pineal Gland (Located in the brain) :

• Hormone : " Melatonin "

• Target Organ : Brain and other tissues

• Function : Regulates the sleep-wake cycle (circadian rhythm) and has antioxidant properties.

4. Thyroid Gland (Located in the neck):

• Hormones : " Thyroid Hormones (T3 and T4) "

• Target Organs : Throughout the body

• Function : Regulates metabolism, energy production, growth, and development.

5. Parathyroid Glands (Located behind the thyroid gland) :

• Hormone : " Parathyroid Hormone (PTH) "

• Target Organs : Bones and Kidneys

• Function : Regulates blood calcium and phosphorus levels, affecting bone health and kidney function.

6. Thymus (Located behind the sternum in the chest) :

• Hormones : " Thymosin and Thymopoietin "

• Target Organ : Immune System (specifically T lymphocytes)

• Function : Plays a vital role in the development and maturation of T cells, which are crucial for immune function.

7.Adrenal Glands (Located on top of each kidney) :

• Hormones : " Cortisol , Aldosterone , Adrenaline and Noradrenaline "

• Target Organs : Various, including muscles, liver, kidneys, and cardiovascular system

• Function : Cortisol helps the body respond to stress and regulates metabolism. Aldosterone regulates electrolyte and fluid balance. Epinephrine and Norepinephrine prepare the body for the "fight or flight" response.

8. Pancreas (Located in the abdomen behind the stomach):

• Hormones : " Insulin , Glucagon "

• Target Organs : Liver, muscles, adipose tissue

• Function : Insulin facilitates glucose uptake into cells, reducing blood sugar levels. Glucagon stimulates the release of glucose into the bloodstream, increasing blood sugar levels.

9. Ovaries (Located in the female pelvis) :

• Hormones : " Estrogen , Progesterone "

• Target Organs : Reproductive system and various tissues

• Function : Regulate the menstrual cycle, support pregnancy, and influence secondary sexual characteristics in females.

10. Testes (Located in the male scrotum) :

• Hormone : Testosterone

• Target Organs : Reproductive system and various tissues

• Function : Regulates sperm production, supports male sexual characteristics, and plays a role in reproductive function and overall health in males.

Endocrine Glands and Hormones

Endocrine Gland	Hormones	Target Organs
Pineal Gland	Melatonin	Brain and other tissues
Hypothalamus	Various hypothalamic hormones	Anterior Pituitary Gland
Anterior Pituitary Gland	TSH, ACTH, GH, PRL, FSH, LH	Various
Posterior Pituitary Gland	ADH (Vasopressin), Oxytocin	Various
Thyroid Gland	T3 and T4 (Thyroid Hormones)	Body cells
Parathyroid Glands	Parathyroid Hormone (PTH)	Bones and Kidneys
Thymus	Thymosin, Thymopoietin	Immune System (specifically T lymphocytes)
Adrenal Glands	Cortisol, Aldosterone, Epinephrine (Adrenaline), Norepinephrine (Noradrenaline)	Various
Pancreas	Insulin, Glucagon	Liver, muscles, adipose tissue
Ovaries (in females)	Estrogen, Progesterone	Reproductive system and other tissues
Testes (in males)	Testosterone	Reproductive system and other tissues