The Endocrine System is the set of glands responsible for the production of hormones that are released into the blood and travel through the body until they reach the target organs on which they act.
Along with the nervous system , the endocrine system coordinates all of our body’s functions. The hypothalamus, a group of nerve cells located at the base of the brain, integrates these two systems.
Glands of the Endocrine System
Endocrine glands are located in different parts of the body: pituitary , thyroid and parathyroids , thymus , adrenals , pancreas and the sex glands .
Hypophysis
The pituitary gland is located in the center of the head, just below the brain. It produces several hormones, including growth hormone.
It is considered the master gland of our body, as it stimulates the functioning of other glands, such as the thyroid and sexual glands.
The excess production of this hormone causes gigantism (exaggerated growth) and the lack causes dwarfism.
Another hormone produced by the pituitary is the antidiuretic ( ADH ), a substance that allows the body to save water in excretion (urine formation).
Thyroid
The thyroid is located in the neck, produces thyroxine , a hormone that controls the speed of cellular metabolism, maintenance of weight and body heat, growth and heart rate.
Hyperthyroidism, exaggerated functioning of the thyroid, accelerates the entire metabolism: the heart beats faster, the body temperature is higher than normal, the person loses weight by expending more energy.
This condition favors the appearance of heart and vascular diseases, as the blood circulates with more pressure. If not treated, it can cause the appearance of goiter (swelling in the neck), and also exophthalmos (bulging eyes).
Hypothyroidism is when the thyroid works less and produces less thyroxine. Thus, the metabolism becomes slower, some regions of the body become swollen, the heart beats more slowly, the blood circulates more slowly, the person spends less energy, tends to put on weight and the physical and mental responses become slower and untreated, goiter can occur.
Parathyroids
The parathyroids are four small glands located behind the thyroid that produce parathyroid hormone , a hormone that regulates the amount of calcium and phosphorus in the blood.
The decrease in this hormone reduces the amount of calcium in the blood and causes the muscles to contract violently.
This symptom is called tetany , as it is similar to what occurs in people with tetanus. In turn, the increased production of this hormone, transfers part of the calcium to the blood, so that it weakens the bones, making them brittle.
Timo
The thymus is situated between the lungs. It produces a hormone that acts to defend the newborn’s body against infections.
At this stage, it has a pronounced volume, growing normally until adolescence, when it begins to atrophy. In adulthood, it decreases in size, as its functions are reduced.
adrenals
The adrenal glands are located above the kidneys and produce adrenaline , a hormone that prepares the body for action. The effects of adrenaline on the body are:
- Tachycardia: the heart races and drives more blood to the legs and arms, increasing the ability to run or get excited in tense situations;
- Increased respiratory rate and blood glucose rate, releasing more energy to cells;
- Contraction of the blood vessels in the skin, so that the body sends more blood to the skeletal muscles and, as a result, we are “pale with fright” and also “frozen with fear”.
pancreas
The pancreas is a mixed gland because in addition to hormones (insulin and glucagon) it also produces pancreatic juice, which is released into the small intestine and plays an important role in digestion.
Insulin controls glucose entry into cells (where it will be used to release energy) and storage in the liver in the form of glycogen.
The lack or low production of insulin causes diabetes , a disease characterized by excess glucose in the blood ( hyperglycemia ).
Glucagon works in the opposite way to insulin. When the body goes many hours without eating, the blood sugar rate drops a lot and the person may have hypoglycemia , which generates the feeling of weakness, dizziness, leading, in many cases, to fainting.
In this case, the pancreas produces glucagon, which acts on the liver, stimulating the “breakdown” of glycogen into glucose molecules. Finally, glucose is sent to the blood normalizing hypoglycemia.
See too:
- Human Body Systems
- stages of human life
sex glands
The sex glands are the ovaries and testes , which are part of the female reproductive system and male reproductive system respectively.
The ovaries and testes are stimulated by hormones produced by the pituitary gland . Thus, while the ovaries produce estrogen and progesterone , the testes produce several hormones, including testosterone , responsible for the appearance of male secondary sexual characteristics: beard, deep voice, bulky shoulders, etc.
