Endocrine System: Hormones and Glands in the Human Body
Endocrine Regulation
The proper functioning of our body is due to the joint coordination of two mechanisms: nervous control and hormonal control. The first is through the action of the nervous system in three sections: central, peripheral, and autonomic. The central control takes place through the action of a group of organs called endocrine glands and internal secretion, which produce chemicals called hormones.
Meaning and Origin of Gland
A gland is an organ whose cells are specialized in the production of substances, i.e., acquiring secretory capacity. These organs originate during embryonic development. The whole training process begins with a gland tissue research epithelial. This research is enhanced to take the form of a sac, whose secretory cells develop. Other glands shut down their communication, rather isolated from the outside, so their products can only be eliminated into the blood capillaries. The third type of gland is one that preserves its communication with the outside, through which it eliminates external secretory products, yet free, and produces and releases hormones into the blood.
Endocrine Glands
Endocrine glands are characterized by producing hormones.
Pituitary Gland
The pituitary gland hangs from the cranial base of the brain within the cranial cavity. The fact that the pituitary is closely connected with the brain determines that it is synchronized through nervous and hormonal mechanisms, regulating body functions properly.
Posterior Lobe
- Oxytocin hormone: Stimulates muscle contraction in different organs.
- Antidiuretic hormone: Stimulates the reuptake of water from the kidneys into the blood.
Intermediate Lobe
- Melanocyte-stimulating hormone: Stimulates the production of melanin, a pigment that darkens the cells of the skin.
Anterior Lobe
- Growth hormone: Stimulates body growth, acting especially on the long bones.
- Thyrotropin hormone: Stimulates the functioning and development of the thyroid gland.
- Adrenocorticotropic hormone: Stimulates the development and functioning of the adrenal glands.
- Gonadotropins Hormones: There are three hormones that, in both men and women, stimulate the maturation of sperm and ovaries and the production of sex hormones by the testes and ovaries, respectively.
Thyroid
The thyroid is a gland in the neck, in front of the trachea. It is stimulated by the pituitary hormone thyrotropin, which is secreted by the hormone thyroxine. This process requires the presence of iodine, which is incorporated into foods such as fish, chocolates, etc. Thyroxine stimulates the metabolic activity of all body cells. Its deficit causes hypothyroidism, which brings with it obesity, fluid retention, mental laziness, etc. Its excess causes hyperthyroidism, characterized by thinness, irritability, insomnia, tachycardia, etc.
Parathyroid Glands
The parathyroid glands are four small glands supported on the back of the thyroid gland. They act independently of the pituitary gland to produce parathyroid hormone, and its function is to stimulate the passage of calcium from the bones into the blood.
Adrenal Glands
The adrenal glands are two glands resting on the top of the kidneys. When cut, two regions are recognized: the external, which produces hormones, and the adrenal medulla, which secretes the hormone adrenaline (related to fear).
Pancreas
The pancreas is a gland in the abdomen, below the stomach. It has mixed secretion. The pancreas has two hormones that are released into the blood: glucagon, which stimulates the passage of glucose from the liver to the blood, and insulin, which facilitates and encourages the penetration of glucose from the blood into cells.
Ovaries
The ovaries are two glands in the pelvic cavity of women. They contain eggs that are formed during the fetal stage and remain immature until puberty.
Testicles
The testicles are two glands in the scrotum of the penis, which produce sperm from puberty.