We know that the human growth hormones start from the pituitary gland in the front side area. Let’s do a little more analysis and research on the gland itself.
From Wikipedia HERE …
In vertebrate anatomy the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is not a part of the brain. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a duralfold (diaphragma sellae). The pituitary is functionally connected to the hypothalamus by the median eminence via a small tube called the infundibular stem (Pituitary stalk). The pituitary fossa, in which the pituitary gland sits, is situated in the sphenoid bone in the middle cranial fossa at the base of the brain. The pituitary gland secretes nine hormones that regulate homeostasis.
The pituitary gland consists of two components: the anterior pituitary (or adenohypophysis) and the posterior pituitary (or neurohypophysis), and is functionally linked to the hypothalamus by the pituitary stalk (also named the “infundibular stem”, or simply the “infundibulum”). It is from the hypothalamus that hypothalamic tropic factors are released to descend down the pituitary stalk to the pituitary gland where they stimulate the release of pituitary hormones. While the pituitary gland is known as the ‘master’ endocrine gland, both of the lobes are under the control of the hypothalamus; the anterior pituitary receives its signals from the parvocellular neurons and the posterior pituitary receives its signals from magnocellular neurons.
Anterior pituitary (Adenohypophysis)
The anterior pituitary synthesizes and secretes the following important endocrine hormones:
- Growth hormone (also referred to as ‘Human Growth Hormone’, ‘HGH’ or ‘GH’ or somatotropin), released under influence of hypothalamic Growth Hormone-Releasing Hormone (GHRH); inhibited by hypothalamic Somatostatin
- Thyroid-stimulating hormone (TSH), released under influence of hypothalamic Thyrotropin-Releasing Hormone (TRH)
- Adrenocorticotropic hormone (ACTH), released under influence of hypothalamic Corticotropin-Releasing Hormone (CRH)
- Beta-endorphin, released under influence of hypothalamic Corticotropin-Releasing Hormone (CRH)
- Prolactin (PRL), also known as ‘Luteotropic’ hormone (LTH), whose release is inconsistently stimulated by hypothalamic TRH, oxytocin, vasopressin, vasoactive intestinal peptide, angiotensin II, neuropeptide Y, galanin, substance P, bombesin-like peptides (gastrin-releasing peptide, neuromedin B and C), and neurotensin, and inhibited by hypothalamic dopamine.
- Luteinizing hormone (also referred to as ‘Lutropin’ or ‘LH’ or, in males, ‘Interstitial Cell-Stimulating Hormone’ (ICSH))
- Follicle-stimulating hormone (FSH), both released under influence of Gonadotropin-Releasing Hormone (GnRH)
- Melanocyte–stimulating hormones (MSHs) or “intermedins,” as these are released by the pars intermedia, which is “the middle part”; adjacent to the posterior pituitary lobe, pars intermedia is a specific part developed from the anterior pituitary lobe.
These hormones are released from the anterior pituitary under the influence of the hypothalamus. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called thehypothalamic-hypophysial portal system.
The anterior pituitary is divided into anatomical regions known as the pars tuberalis, pars intermedia, and pars distalis. It develops from a depression in the dorsal wall of the pharynx (stomodial part) known as Rathke’s pouch.
Posterior pituitary (Neurohypophysis)
The posterior pituitary stores and secretes the following important endocrine hormones:
- Oxytocin, most of which is released from the paraventricular nucleus in the hypothalamus
- Antidiuretic hormone (ADH, also known as vasopressin and AVP, arginine vasopressin), the majority of which is released from the supraoptic nucleus in the hypothalamus
Oxytocin is one of the few hormones to create a positive feedback loop. For example, uterine contractions stimulate the release of oxytocin from the posterior pituitary, which, in turn, increases uterine contractions. This positive feedback loop continues throughout labor.
Although rudimentary in humans (and often considered part of the anterior pituitary), the intermediate lobe located between the anterior and posterior pituitary is important to many animals. For instance, in fish, it is believed to control physiological color change. In adult humans, it is just a thin layer of cells between the anterior and posterior pituitary. The intermediate lobe produces melanocyte-stimulating hormone(MSH), although this function is often (imprecisely) attributed to the anterior pituitary.
Variations among vertebrates
The pituitary gland is found in all vertebrates, but its structure varies between different groups.
The division of the pituitary described above is typical of mammals, and is also true, to varying degrees, of all tetrapods. However, only in mammals does the posterior pituitary have a compact shape. Inlungfishes, it is a relatively flat sheet of tissue lying above the anterior pituitary, and, in amphibians, reptiles, and birds, it becomes increasingly well developed. The intermediate lobe is, in general, not well developed in tetrapods, and is entirely absent in birds.
Apart from lungfishes, the structure of the pituitary in fish is generally different from that in tetrapods. In general, the intermediate lobe tends to be well developed, and may equal the remainder of the anterior pituitary in size. The posterior lobe typically forms a sheet of tissue at the base of the pituitary stalk, and in most cases sends irregular finger-like projection into the tissue of the anterior pituitary, which lies directly beneath it. The anterior pituitary is typically divided into two regions, a more anterior rostral portion and a posterior proximal portion, but the boundary between the two is often not clearly marked. Inelasmobranchs there is an additional, ventral lobe beneath the anterior pituitary proper.
The arrangement in lampreys, which are among the most primitive of all fish, may indicate how the pituitary originally evolved in ancestral vertebrates. Here, the posterior pituitary is a simple flat sheet of tissue at the base of the brain, and there is no pituitary stalk. Rathke’s pouch remains open to the outside, close to the nasal openings. Closely associated with the pouch are three distinct clusters of glandular tissue, corresponding to the intermediate lobe, and the rostral and proximal portions of the anterior pituitary. These various parts are separated by meningial membranes, suggesting that the pituitary of other vertebrates may have formed from the fusion of a pair of separate, but associated, glands.
Most armadillo also possess a urophysis, a neural secretory gland very similar in form to the posterior pituitary, but located in the tail and associated with the spinal cord. This may have a function inosmoregulation.
There is an analogous structure in the octopus brain.[6
From the Department Of Neurological Surgery at the University of Pittburgh website HERE…
From the website Cancer.Net HERE ….
About the pituitary gland
The pituitary gland is a small gland located near the brain. This gland is often referred to as the “master endocrine gland” because it releases hormones that affect many bodily functions. The pituitary gland is controlled by the hypothalamus, a small structure also near the brain that is connected to the pituitary gland. A pituitary gland has two lobes, the anterior (front) and the posterior (back), and each lobe is responsible for releasing specific hormones. These different hormones include:
Anterior pituitary lobe hormones
- Thyroid stimulating hormone (TSH) stimulates the thyroid gland, which helps regulate the body’s metabolism
- Adrenocorticotrophic hormone (ACTH) controls the hormones released by the adrenal gland that support blood pressure, metabolism, and the body’s response to stress
- Gonadotropins (Follicle stimulating hormone or FSH and Luteinizing hormone or LH) stimulate production of sperm in a man’s testicles or eggs in a woman’s ovaries and regulate a woman’s menstrual cycle
- Growth hormone promotes growth of the long bones in the arms and legs, thickens the skull and bones of the spine, and causes the tissue over the bones to thicken
- Prolactin stimulates milk production in women after childbirth
- Lipotropin stimulates the movement of fat from the body to the bloodstream
- Melanocyte stimulating hormone (MSH) regulates the production of melanin, the pigment in skin
Posterior pituitary lobe hormones
- Oxytocin stimulates contraction of the uterus during childbirth and the flow of milk during breastfeeding
- Antidiuretic hormone (called vasopressin) increases reabsorption of water by the kidneys and allows a person to stay hydrated
Tumors in the pituitary gland
When normal cells change and grow uncontrollably, they can form a mass called a tumor. A pituitary gland tumor can be benign (noncancerous and located only in the pituitary gland) or malignant (cancerous, meaning it can spread to other parts of the body). Most often, pituitary gland tumors are noncancerous growths and are called pituitary adenomas. However, a pituitary gland tumor can occasionally act like a cancerous tumor by growing into nearby tissue and structures, or rarely, spreading to other parts of the body.
Pituitary gland tumors are NOT brain tumors, as the pituitary gland is located under and is separate from the brain. However, a tumor in this gland can be very serious because a pituitary gland that doesn’t work can cause problems with other organs. The tumor can also press on nearby structures, such as the optic nerves, impairing a person’s sight.
Me: The big thing for us height seekers to note is that the Pituitary gland is not actually a part of the brain but actually the lower part of the hypothalamus and is connected by a small tube called the infundibular stem (Pituitary stalk). It releases 9 major hormones that regulate the body’s homeostasis. There is two parts to it although the truth is that the gland is actually a combination of different functioning cells. The HGH is just one of the 9 hormones being released. The hormone release is regulated by the either the growth hormone releasing hormone (GHRH) or the growth hormone inhibiting hormone (GHIH) which is released by the hypothalamus. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called thehypothalamic-hypophysial portal system. The pituitary giants we get are usually from the clumping of certain cells in the pituitary coming together which is usually benign.