Informational chemical molecules are called hormones. Chemically, hormones can be classified into three broad categories:
- Eicosanoids
- Amino acid/protein derivatives (amines, proteins, and peptides)
- Steroids
Where are Hormones secreted from?
The endocrine glands in the body produce hormones. A lack of ducts in the glands means hormones are secreted directly into the bloodstream. The following are some of the body’s most important endocrine glands:
- Pituitary gland
- Pineal gland
- Thymus
- Thyroid
- Adrenal glands
- Pancreas
- Testes
- Ovaries
Hormones secreted by these organs have a significant impact on the body. Even the tiniest excess or deficiency of a hormone can cause disease.
Pituitary Gland: Definition
This gland is very small. It is the size of a large pea seed, but it is a crucial gland that controls the functions of all the other endocrine glands in the body. It is therefore called the master gland of the body. This gland is located in the bony cavity of the body known as sella turcica and is attached to the hypothalamus. It has three parts: Anterior, Posterior and Middle.
Pituitary Hormones
The pituitary gland is an organ that secretes hormones. These hormones travel through the bloodstream to all parts of the body. All the cells in the body are connected by the hormones secreted by the pituitary gland. The pituitary gland secretes several hormones. Theses include:
Growth Hormone
The Human Growth Hormone (HGH), commonly known as growth hormone, is a vital hormone secreted by the pituitary gland, responsible for the human body’s growth. The HGH is responsible for the development of human beings during their primitive years (0-18 years). If the HGH is secreted less than the required quantity, it leads to dwarfism. And if the HGH is secreted more than the necessary quantity or is secreted even after the primitive years, it leads to a condition called Acromegaly or Gigantism.
Thyroid Stimulating Hormone
The pituitary gland secretes this hormone to control the functioning of the thyroid gland. The thyroid gland secretes hormones that control the metabolism rate of the body. The pituitary gland indirectly controls the body’s metabolism; hence it is called the Master Gland.
Adrenocorticotropic Hormone
This hormone is commonly called ACTH, and it controls the functioning of the adrenal gland. The adrenal gland includes a pair of glands situated on the kidneys. They secrete adrenaline hormone, also known as the ‘flight or fight response hormone. Hence the pituitary gland also controls the adrenal glands.
Endorphins
Endorphins are hormones secreted by the pituitary gland, often called pleasure hormones. This hormone is responsible for relieving stress pain and bringing in happy thoughts.
Prolactin
Prolactin hormone is secreted in females, especially in breastfeeding females. The pituitary gland again regulates this hormone.
Vasopressin
This hormone is secreted by the posterior lobe of the pituitary gland. It helps in various functions like regulating the water levels in the body, maintaining salt levels, etc.
Oxytocin
This hormone is again secreted by the posterior lobe of the pituitary gland. It is secreted in females and helps in milk generation for breastfeeding and also helps in inducing labour in pregnant women by contraction of the uterus.
Luteinising Hormone
This hormone is secreted by the anterior lobe of the pituitary gland and is responsible for regulating the oestrogen levels in the female body. Oestrogen is a female reproductive hormone secreted primarily by female reproductive organs.
Size and Location of the Pituitary Gland
The pituitary gland is of the size and shape of a pea and weighs around 0.5 grams. It is located at the base of our skull, behind the nose bridge.
It is the topmost gland in the human body. The pituitary gland is protected by a small bone cavity called Sella turcica, a sphenoid bone projection. This gland is divided into the anterior lobe, almost 80% of the entire gland and the posterior lobe.
Conclusion :
The pituitary is an endocrine gland in the midbrain and has two prominent lobes. The anterior lobe secretes hormones under the hypothalamus’s indirect control, while the posterior pituitary is under the direct control of the hypothalamus. Hormones secreted by the pituitary have a direct impact on growth and other hormones that reach all the other endocrine glands of the body and regulate their functioning. The hypo or hypersecretion of pituitary hormones results in various disorders.