General overview of the human body: systems, structure and functions. How is the person

The human body is a mysterious, complex mechanism that can not only perform physical actions, but also feel, think. A general overview of the human body shows that out of the seven billion living on the Earth there are absolutely similar people outwardly, but the structure of the body is 99% in all the same. Nature arranged so that with a clear, well-coordinated work of all organs, the mechanisms of vital activity ensure a long existence for our body.

General overview of the human body

The human body is a single organism, where the action of all organs and systems is closely related. The basic unit is the cell. By the time the adult reaches the state, the human body consists of an average of three billion cells. All bodies are formed from them , the organs are integrated into systems, each of which plays an important role in life activity. Human body systems:

• The cardiovascular system. It includes capillaries, arteries, veins, and the heart. The main function of the system is pumping blood, delivering it to all organs. The left part of the heart is a "pump" for the whole organism, the right side of the heart muscle delivers blood to the lungs in order to enrich it with oxygen. The heart has three layers (myocardium, epicardium, endocardium). Each of them has different density and functional.
• The digestive system satisfies the need for food and processes nutrients into the necessary energy. It consists of the digestive tract: the oral cavity, esophagus, stomach, small intestine, colon, ends with a rectum.
• Skin covering. The vital activity of the human body is constantly associated with various risks. The skin protects the body from the effects of the environment, external irritants. The skin system consists of the skin (including the sebaceous and sweat glands), hair, nails and micromuscles that hold the hair.
• Lymphatic system. The main function is the extraction and transportation of lymph throughout the body.
• The musculoskeletal system. It consists of a human skeleton in which all the bones are aligned with each other with joints, supported by muscles attached to the skeleton by tendons. The study of the human body often begins with the study of the structure of the skeleton. In general, the skeleton consists of 206 bones.
• Nervous system. The nervous system carries responsibility for information about the body and the environment in the body. It is divided into peripheral and central.
• Reproductive system. The most complex system of the body, completely different from the female to the male. Responsible for sexual function and, in general, for the continuation of the human race.

How people work: the arrangement of organs. Head

Each human organ is individual, located in a certain place and performs its function. When making an overview of the human body, it is important to understand where the organ is located. This will help to avoid any injuries, as well as determine to which specialist to handle a particular disease.

The brain, perhaps, remains the most mysterious and undiscovered element of the body. All parts of the body obey this center. The brain is located in the cranium, protected by strong bones of the skull. From the brain all over the body, nerves are running, through which impulse signals are sent to this or that action. Thanks to the commands of the brain, we see, hear, feel, move, generally live and exist.

Rib cage

Everyone should know how the person works, where the main organs are located. Consider the chest. On the anterior, cervical side, under the Adam's apple, there is a small thyroid gland, it can be called a "battery" of our body. She is responsible for the development of the basic hormones that provide all the coordinated work of the organs of our body. With age, the thyroid gland can go down and even be in the chest cavity.

The thoracic cavity from the abdominal separates the muscular organ from the diaphragm. The heart is displaced to the left, is located between the right and left lungs, behind the breastbone. Lungs occupy most of the space of the chest. Pass from the heart to the ribs, have a domed shape, behind are located towards the spine. The bases of the lungs rest against the muscular diaphragm. Protected by ribs.

Abdomen

The main reservoir for taking, storing food is the stomach. It is located under the diaphragm, in the left part of the peritoneum. Behind, just below the stomach, is the pancreas. It breaks down fats, carbohydrates, proteins and produces glucagon and insulin - the most important hormones.

On the right, under the diaphragm, is the liver. Well-coordinated work of the human body largely depends on this body. The liver is our main filter. In the lower part of the liver, in the depression, there is a gallbladder, which plays an important role in the processing of food. In the left part of the hypochondrium lies the spleen, it protects our body from various infections, as well as from the loss of blood.

Intestines

Below the stomach abdominal space occupies the small intestine, representing a long tangled tube. The beginning of the large intestine (the caecum) is on the right side. Then the large intestine flows around the peritoneum on top and descends downwards along the left side. The blind gut is called an appendix. The large intestine passes into the straight line, ends with the anus - the exit through which the stool masses are removed.

Genitourinary organs

Considering the systems of the human body, you understand that each of them is important and necessary in its own way. The kidneys are related to the paired organs of the genitourinary system. The left kidney is located a little higher because of the increased size of the liver on the right. On the top of each kidney are the adrenal glands. Their role is huge, they are allocated more than thirty hormones directly into the bloodstream. Below, in a small pelvis, is the bladder. At men behind it - seminal vesicles, an intestine. In women - the vagina, from below - the muscles of the pelvic floor. Two tiny glands - the ovaries lie in the pelvic cavity, on opposite sides of the uterus, are attached to it by ligaments. In men, testes (testes) are in the scrotum, which is brought out. Below the bladder is the prostate gland.

Cell

Carrying out a general overview of the human body, we put the cell first. It is the smallest functional and structural unit. In the human body - more than two hundred types of cells, each of them has its own composition, functional, structure. If we consider the general plan of the structure, it is the same. The shell, cytoplasm and nucleus are the main components of any cell. The envelope forms glycocalyx and plasmalemma. In the cytoplasm, the organoid and the hyaloplasm differ.

The cell envelope provides a receptor function, selective permeability, the transmission of electrical and chemical signals, separates the intercellular substance from the protoplast.

The main properties of cells in life are irritability, metabolism, reproduction, aging, death.

Metabolism occurs continuously. The cell constantly includes various substances that take part in the energy and plastic exchange, the used components are extracted, and thermal energy is released.

The cell is capable of responding to various internal and external stimuli. The form of the response is excitability, it is associated with the charge of the cell membrane.

Each cell has its own life cycle. Every day in the human body about 1-2% of cells die as a result of aging and new ones are born, this process is continuous.

Fabrics

A tissue is a collection of cells, intercellular substance, which have a common structure, functions, origin. In the human body, there are four types of tissues:

• Epithelial tissue. It is based on ectodermal origin, quickly regenerates, has a minimum of intercellular substance, no vessels, is located on the basal membrane. There are several types of epithelium: single-layered - flat, cylindrical, cubic, ciliated epithelium, multilayered - keratinizing, non-coronary, glandular epithelium.
• Connective tissue. Comes from the mesoderm. The cell form is diverse, the intercellular substance is developed. Distinguish fibrous - loose tissue, dense tissue, cartilage, bone, fat, lymph, blood. Hemostatic tissues also belong to the connective tissue.
• Muscle. It has properties to contract and be excited. The skeletal cross-striped, cardiac cross-striped, smooth is distinguished.
• Nervous tissue. The most important properties are excitability and conductivity. The tissue of ectoderm origin is represented by neuroglia and neurons.

Systems, functions of organs

So, we examined the structure and functions of the human body. We generalize the results obtained and represent all the functions of individual systems in the form of a table.

As you can see, the human body is an integral dynamic system with a special structure.