Today we will talk about the anatomy of the human endocrine system . To begin with, what is it all about. It is very important to know that the endocrine and nervous systems of a person in a joint work have a direct effect on all organs and systems of the body. It is thanks to them that the functioning of all parts as a single mechanism is possible.
What applies to the endocrine system? Endocrine glands:
- nuclei of the hypothalamus;
- pituitary gland;
- pineal gland;
- parathyroid glands;
- thyroid;
- parathyroid glands;
- thymus
- partially pancreas;
- partially gonads;
- adrenal glands;
- gonads.
Note that the entire endocrine system is represented not only by the endocrine glands that were listed above, but also by the APUD system (endocrine cells that are scattered throughout the body are called apudocytes).
The glands that we have just talked about secrete hormones that can both stimulate and weaken the functioning of cells, tissues and organs.
Nervous and endocrine system
Considering the anatomy and physiology of the endocrine system, we cannot but note its connection with the human nervous system. The latter can send impulses directly to the innervated organ, which leads to an inadequate response. The following very important body functions lend themselves to hormonal influences:
- Metabolism.
- Somatic growth.
- Reproductive function.
How can one very simply explain the connection between these two systems? The thing is that the regulatory effect of the endocrine and nervous system is implemented by the same mechanism.
Note the recent discovery. The nervous system includes neurons that can secrete hormones that simulate the endocrine system. They are called peptidergic. Based on the foregoing, we can conclude: the human nervous system, together with the endocrine, represents a single neuroendocrine regulatory system.
Endocrine glands
Earlier, when the science of endocrinology was just beginning to emerge, little was known about the functional anatomy of the endocrine system. Initially, the glands were grouped by the origin of the embryonic rudiment of the leaves. Expanding knowledge, people realized that this is a wrong classification.
Currently, two groups of glands are distinguished:
- Neuroendocrine transmitters (when hormones are produced, they can redirect information from the central nervous system to the adenohypophysis).
- Neurohemal organs.
The entire endocrine system, the brief anatomy of which we consider in this article, is represented by several structural components:
- central regulatory education (this includes the hypothalamus, pituitary and pineal gland);
- peripheral gland (thyroid, parathyroid, adrenal glands and their medulla);
- an organ that combines the functions of endocrine and non-endocrine (gonads, testis, ovary, placenta and pancreas);
- single hormone producing cells (APUD cells and non-nervous hormone producing cells).
Hypothalamus
Considering the anatomy of the human endocrine system, we cannot pass by the hypothalamus, which performs a number of very important functions:
- maintaining metabolic rate;
- maintenance of the digestive system;
- regulatory function of the activity of the cardiovascular and other physiological systems of our body.
What is it? This is a small area of the brain (sub-tubercle) located under the visual tubercles. It is he who forms the walls and the bottom of the third ventricle, also the hypothalamus is part of the diencephalon. It is a set of adaptive centers that carry out the integration and adaptation of all functions, as a result, the integral activity of the body becomes possible.
Pituitary
In this section, we consider the pituitary gland of the human endocrine system. Anatomy is where we propose starting.
Please note that the pituitary gland is divided into two lobes:
- adenohypophysis;
- neurohypophysis
The first share is also divided into parts:
- anterior (trabecular structure, trabeculae form a narrow-braided network, the spaces between which are filled with connective tissue of loose consistency, and multiple sinusoidal capillaries pass through it);
- medium (a narrow strip of multilayer epithelium, protein secretion is produced here, which can accumulate between cells, forming cysts);
- tubular.
Now we pass to the second (back) lobe of the pituitary gland. Its pituititam cells resemble the shape of a spindle. There is an accumulation of vasopressin and oxytocin.
Thyroid
Of great importance in the anatomy of the endocrine system is the thyroid gland, which produces hormones containing iodine. In addition, this body regulates the metabolism and energy of the body.
The good functioning of the thyroid gland is very important, since many biological processes depend on it:
- Height.
- Development.
- Tissue differentiation.
This endocrine organ produces three types of hormones:
- Thyroxine (increases the excitability of the nervous system and speeds up the metabolic process).
- Triiodothyronine (similar to the previous one).
- Calcitonin (reduces the excitability of the nervous system, lowering the level of calcium in the blood, also increases the content of this element in the bone tissue).
Parathyroid glands
Now consider the parathyroid glands of the endocrine system, the anatomy of the structure (briefly). In total there can be from 4 to 6, they are located at each pole of the thyroid gland, from where their name is taken. Each individual gland is covered with a thin capsule, the parenchyma is formed by trabeculae or paratyrocytes, they are separated by a connective tissue of loose consistency, where there are numerous capillaries.
The parathyroid glands are involved in the production of parathyroid hormone (a protein formed by 84 amino acid residues connected in one long chain). Their activity directly depends on the amount of calcium in the blood, when it is not enough, the production of the hormone increases. When we eat, the calcium level fluctuates greatly, and the task of the parathyroid glands is to maintain the level of this element in the norm, regardless of the food we eat.
Adrenal glands
These are paired glands located above the kidneys. Note that this is a paired organ, but the forms of the left and right are different. Right - triangular, left in the shape of a crescent. These glands are yellow. The produced hormones are able to penetrate the bloodstream, so they participate in the regulation of the life of the whole organism. They are very small in size, their weight is only from 3.5 to 5 grams.
The left and right gland consists of two parts:
- Cortical layer (production of sex hormones of mineralocorticoids and glucocorticoids).
- The cerebral layer (production of adrenaline and norepinephrine).
Pathological anatomy of the endocrine system (briefly)
Forms of the pathology of the hypothalamus:
- violation of the production of liberins;
- pathology of ADH;
- oxytocin deficiency.
Groups of pathologies of the adenohypophysis:
- hypopituitarism;
- hyperpituitarism;
- idituitarism.
Pathological conditions of the pineal gland:
- Marburg-Milku syndrome;
- Pellizzi syndrome.
Disorders of the parathyroid glands:
- hyperparathyroidism;
- hypoparathyroidism.
Thyroid diseases are very common, the most common:
- goiter;
- thyroiditis;
- tumors.
The most common pancreatic pathologies:
- diabetes;
- Mallison syndrome;
- Werner-Morrison syndrome.
Note that the most common disease of the endocrine system is diabetes, which can be caused not only by the pathological condition of the pancreas.