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

The human body is a mysterious, complex mechanism that can not only perform physical actions, but also feel, think. A general review of the human body shows that out of the seven billion people living on Earth there are no people who are absolutely similar in appearance, but the body structure is 99% the same for everyone. Nature arranged in such a way that with a clear, harmonious work of all organs, the mechanisms of vital activity ensure a long existence for our body.

General review 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 it reaches adulthood, the human body has an average of three billion cells. All organs are formed from them , organs are combined into systems, each of which plays an important role in life. Human body systems:

• The cardiovascular system. It includes capillaries, arteries, veins, heart. The main function of the system is pumping blood, delivering it to all organs. The left side 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 a different density and functionality.
• The digestive system satisfies the need for food and processes nutrients into necessary energy. It consists of the digestive tract: oral cavity, esophagus, stomach, small intestine, colon, ends with the rectum.
• Skin covering. The vital activity of the human body is constantly associated with various risks. The skin protects the body from environmental influences, external irritants. The skin system consists of skin (including sebaceous and sweat glands), hair, nails and micro-muscles that hold hair.
• Lymphatic system. The main function is the extraction and transportation of lymph through the body.
• Musculoskeletal system. It consists of the human skeleton, in which all bones are aligned with each other by joints, supported by muscles attached to the skeleton by tendons. The study of the human body often begins with a study of the structure of the skeleton. In general, the skeleton consists of 206 bones.
• Nervous system. The nervous system in the body is responsible for information about the body and the environment. It is divided into peripheral and central.
• Reproductive system. The most complex system of the body, completely different from the female male. Responsible for sexual function and in general for the continuation of the human race.

How a person works: the location of organs. Head

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

The brain, perhaps, remains the most mysterious and undisclosed element of the body. All parts of the body obey this center. The brain is located in the skull, protected by strong bones of the skull. From the brain, nerves scatter throughout the body, through which impulse signals to a particular action come. Thanks to the commands of the brain, we see, hear, feel, move, generally live and exist.

Rib cage

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

The thoracic cavity from the abdominal cavity is separated by the muscular organ of the diaphragm. The heart is shifted to the left, located between the right and left lungs, behind the sternum. The lungs occupy most of the chest space. Pass from the heart to the ribs, have a domed shape, are located behind in the direction of the spine. The bases of the lungs rest against the muscle diaphragm. Protected by ribs.

Abdomen

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

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

Intestines

Below the stomach, the peritoneal space is occupied by the small intestine, representing a long tangled tube. The beginning of the large intestine (cecum) is on the right side. Then the colon flows around the peritoneum on top and descends down the left side. The cecum is called the appendix. The large intestine passes into the rectum, ends with the anus - the exit through which the feces 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 belong to the paired organs of the genitourinary system. The left kidney is located slightly higher due to the enlarged liver located on the right. At the top of each kidney are the adrenal glands. Their role is huge, they secrete more than thirty hormones directly into the bloodstream. Below, in the pelvis, is the bladder. In men, there are seminal vesicles, intestines. In women - the vagina, below - the pelvic floor muscles. Two tiny glands - the ovaries lie in the pelvic cavity, on opposite sides of the uterus, attached to it by ligaments. In men, the testes (testicles) are in the scrotum, which is brought out. Below the bladder is the prostate gland.

Cell

Carrying out a general review of the human body, we put the cell in the first place. 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 membrane, cytoplasm and nucleus are the main components of any cell. The shell forms glycocalyx and plasmalemma. In the cytoplasm, the organoid and hyaloplasm are distinguished.

The cell membrane provides receptor function, selective permeability, 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. Various substances that take part in energy and plastic metabolism constantly enter the cell, the used components are excreted, and thermal energy is released.

The cell is able to respond to various internal and external stimuli. The response form 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 arise, this process is continuous.

Fabrics

Tissue is a collection of cells, intercellular substance, which have a common structure, function, origin. There are four types of tissue in the human body:

• Epithelial tissue. It is based on ectodermal origin, quickly regenerates, has a minimum of intercellular substance, there are no vessels, it is located on the basement membrane. Several types of epithelium are distinguished: single-layered - flat, cylindrical, cubic, ciliated epithelium, multilayered - keratinized, non-keratinized, glandular epithelium.
• Connective tissue. Comes from the mesoderm. The shape of the cells is diverse, intercellular substance is developed. There are fibrous - loose tissue, dense tissue, cartilage, bone, fat, lymph, blood. Hematopoietic tissues also belong to the connective.
• Muscle. It has the ability to contract and be excited. There is skeletal striated, cardiac striated, smooth.
• Nerve tissue. The most important properties are excitability and conductivity. Tissue of ectodermal origin, represented by neuroglia and neurons.

Systems, organ functions

So, we examined the structure and functions of the human body. We summarize the results and present all the functions of individual systems in a table.

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