Humoral regulation, exocrine and endocrine glands are concepts that you will learn about in this article. Together with the nervous system, they ensure the smooth functioning of the whole organism. How does this happen?
The mechanism of action of humoral regulation
All physiological processes in the human body are carried out in two ways. The nervous system provides responses and a direct relationship with environmental factors.
Humoral regulation is carried out with the participation of special chemicals - hormones. They are produced by organs called glands. Hormones are carried by blood, tissue fluid, or lymph. Under their influence, morphological and physiological changes occur, which are aimed at ensuring the normal functioning of the body. The action of hormones can be characterized as slow and long, in contrast to nervous regulation, which is carried out quickly and for a short time.
Exocrine and endocrine glands: differences
In the human body, several types of glands are distinguished. They can be external or internal secretion. In another way they are called exocrine and endocrine glands. The former release their products (secrets) into the external environment or body cavity. The functions of exocrine glands are diverse. The largest of them is the liver. It cleanses the body of toxins and is involved in blood formation processes. Sweat provides thermoregulation, sebaceous moisturize and lubricate the skin. Bulbourethral glands also belong to this group. They are also called cooper. These are typical glands of external secretion, which belong to the male reproductive system. They secrete their secret, which contains a large amount of mucus and enzymes, into the urethra. This substance promotes the movement of sperm, neutralizes the acidic environment and prevents the mucosa from irritation.
Like exocrine, endocrine glands secrete secrets. But they contain hormones - biologically active substances that are released directly into the blood. These substances have a number of specific features. They act in very small concentrations, change the rate of chemical reactions, and their effect is controlled by the nervous system.
Mixed secretion glands
In addition to exocrine and endocrine glands, there is another group. They secrete two types of hormones. One of them enters the bloodstream, the other into the cavity of the internal organs. Examples of these are the genital and pancreas. This secretion is called mixed.
Gonads
Man is a dioecious organism. Male reproductive glands (testicles) and female reproductive (ovaries) produce germ cells. They secrete gametes - eggs and sperm. The process of their merger (or fertilization) occurs in the fallopian tube. This is how external secretion manifests itself.
Hormones are also formed in the gonads. Female ones are called estrogens, and male ones are called androgens. They are secreted into the bloodstream. During the period of embryonic development, these substances control the formation of the corresponding genital organs, and in the teenage period, secondary sexual characteristics. This is the internal secretion of the gonads.
Pancreas
It is also a mixed secretion organ. The exocrine part of the pancreas produces digestive juice. It is secreted into the duodenum. Gastric juice is a clear liquid, which includes hydrochloric acid, mucin mucus and enzymes - pepsin and lipase. As a result of the action of these substances, the breakdown of organic substances, the neutralization of pathogenic bacteria, and the stimulation of the motor activity of the stomach occur.
As an endocrine gland, the pancreas secretes the hormones insulin and glucagon, which regulate carbohydrate metabolism. The first promotes the conversion of glucose into glycogen, which is deposited in the liver. Glucagon has the opposite effect. If an insufficient amount of insulin is secreted in the body, this leads to an increase in the concentration of sugar in the blood and a violation of metabolic processes. This disease is called diabetes.
Pituitary
This endocrine gland is located at the base of the brain. It secretes growth hormone. With its excess (hyperfunction), gigantism develops at a young age, and with a deficiency (hypofunction), dwarfism develops. If growth hormone is secreted in large quantities in an adult, it causes acromegaly - excessive growth of individual parts of the body.
Thyroid
This organ is attached to the trachea and larynx with the help of fibrous tissue. The thyroid is the largest endocrine gland. It secretes iodine-containing hormones - thyroxine and triiodopsin. They regulate the release of energy, growth and development of nerve tissue. Hyperfunction of the thyroid gland leads to the development of a base disease, which is manifested by excessive excitability, weight loss, trembling in the limbs. If the food contains insufficient iodine, this can lead to the appearance of endemic goiter. So they call an increase in the size of the thyroid gland.
Adrenal glands
You probably noticed that in a stressful situation there is a mobilization of the body's forces and an increase in muscle performance. This is possible due to the action of adrenaline - a hormone secreted by the adrenal glands. The action of this substance leads to an increase in glucose levels. This provides the muscles with the necessary energy, increases their performance, mobilizes the activity of the cardiovascular system.
Thymus gland (thymus)
This unpaired endocrine gland is formed by glandular cells and reticular tissue. In humans, its formation is completed only by puberty. After that, the reverse process begins. Reticular tissue of the thymus atrophies and is replaced by fat. The thymus hormone called thymosin affects the production of T-lymphocytes. These are blood cells that form humoral immunity. The essence of this process is the formation of specific antibodies that destroy foreign microorganisms.
So, humoral regulation in the human body is carried out using the endocrine system. It includes the endocrine glands. Their examples are the thymus gland (thymus), pituitary, pineal, thyroid. They secrete their secrets containing hormones into the blood. Exocrine include salivary, sweat, sebaceous, mammary, bulbourethral glands . They secrete their products outward or in the body cavity. In addition to exocrine and endocrine glands in the body, there are also mixed ones - sexual and pancreas. They secrete hormones in the blood, gametes and digestive juice in the organs.