Human Body Systems (Meaning and Explanation)

We explain what the human body systems are, what their various functions are and their main characteristics.

What are the systems of the human body?

When we talk about the systems of the human body we refer to the different sets of organs that make it up, collaborating in each case with the fulfillment of some specific type of functions. Seen this way, our body can be understood precisely as a simultaneous and juxtaposed set of systems, whose correct functioning keeps us alive.

Each of these systems of the human body involves different (and sometimes the same) organs, as well as various ducts, tissues and glands, all coordinated through endocrine substances and nervous impulses in order to operate more or less autonomously as the case may be.

This systemic understanding of the human body is particularly useful for medicine, which often consists of specialized branches in each of these systems: cardiology, endocrinology, gastroenterology, etc.

Nervous system

The nervous system is the main control system of the human body which involves a very extensive network of nerves, made up of thousands of nerve cells (neurons and gliomas, mainly). This system fulfills the function of voluntary movement and decision making, as well as consciousness; but also with the internal and passive control of the organism, such as the regulation of involuntary movements, reflexes and other forms of transmission of nervous information, such as the senses, pain, pleasure, etc.

The nervous system can be classified into the Central Nervous System, which makes up the brain, cerebellum and telencephalon, located within the skull, as well as the spinal cord within the vertebral column, to which a vast network of nerves is connected. of different size and importance that make up the Peripheral Nervous System.

endocrine system

This is the name given to a complex system of internal regulation, which uses biochemical compounds called hormones. to start, regulate or stop various processes in the body. These hormones are produced by the body's glands and released into the blood, through which they travel to their destination. Thanks to hormones, metabolic, sexual and growth aspects of the body, and even thermoregulation, can be regulated.

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Respiratory system

It is the one that involves oxygenation of the blood and expulsion of carbon dioxide processes essential for cellular respiration and energy metabolism. This device involves the lungs, the bronchi and the entire air passage from outside the body to them: the trachea, pharynx, larynx, nose and the muscle that allows the inflation and deflation of the lungs: the diaphragm.

Breathing is a semi-reflex movement, which can be controlled but not prevented voluntarily and which occurs by expanding the rib cage so that air enters through the nasal passages, where it is filtered by the nasal hairs, and descends to the lungs and in the bronchi, oxygen permeates into the blood. At the same time, the carbon dioxide accumulated in it is retained and exhaled in the opposite direction through the same ducts.

circulatory system

Blood is the vehicle for oxygen that enters through the lungs and must be distributed throughout the body. To do this, the blood covers an enormous network of arteries and capillaries that They carry oxygenated blood to every corner and veins that collect blood loaded with carbon dioxide and make the return journey to the lungs, to begin the circuit again.

The driving force of this movement It is a muscle that constantly beats in our chest and is called the heart. It operates like a pump, sucking blood and pushing it back through a system of independent cavities that prevent arterial blood and vein blood from mixing. This role is essential in the body and any defect that reduces the capacity of the heart has effects on general health.

digestive system

This is the system necessary for nutrition and feeding, that is, the assimilation of organic matter from outside the body. The circuit of this system begins with the mouth, tongue and teeth, as well as the salivary glands. There the food is cut, crushed, moistened and prepared (since called “food bolus”) for its descent through the esophagus until it reaches the stomach, a kind of cauldron of gastric acids that disintegrate the food and reduce it to its most basic elements.

In this process The liver and pancreas also participate whose hormones and substances prepare everything for the absorption of nutrients, which occurs in the intestine (small intestine first and then large intestine), thanks to a series of villi that connect with the blood capillaries.

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Once the nutrients are retained, the rest of the ingested organic matter continues its course towards the large intestine and its final parts: cecum, colon and rectum, where they are stored until the time comes for their expulsion through the anus, in defecation.

Continue in: Digestive system

excretory system

Also called the urinary system, it is the system responsible for freeing the body from harmful substances and metabolic waste, the accumulation of which in the body is risky. For this, it has two types of expulsion routes:

The sweat glands They are found along the skin and expel sweat, a saline liquid in which we get rid of many harmful substances and pathogenic microorganisms.
The urinary system Composed of the kidneys, blood filters in which metabolic waste substances (such as urea) are deposited and converted into urine, which is then stored in the bladder, where it reaches through the ureters after various reabsorption and filtration processes. usable substances. When there is enough urine (about 400 cc) it is expelled through the urethra out of the body, in what is known as urination.

reproductive system

This is the system that guarantees the human body its ability to procreate, that is, to generate new individuals of the species. Since our reproduction is always sexual, this apparatus is substantially distinguished between men and women, in the following way:

Male reproductive system. It is primarily composed of the penis, a highly sensitive organ that forms cavernous bodies that can fill with blood during sexual excitement, thus generating its erection and hardening, ready to penetrate the female genital tract. Then there are the man's external sex glands, the testicles, located in the scrotum, in separate sacs below the penis. There, male gametes, sperm, are constantly produced, along with a substance that accompanies and nourishes them, semen, also produced thanks to the intervention of an internal organ known as the prostate. All of this is ejaculated during intercourse inside the woman's body, so that fertilization occurs there.
Female reproductive system Like the male, it has sexual glands known as ovaries, where the female gametes are formed: the eggs. These descend to the uterus through a channel known as the fallopian tubes once a month, and if they are not fertilized, they are eliminated along with menstruation. There in the uterus is where the union of sperm and egg occurs, to give rise to a zygote from which a fetus will be produced. During intercourse, the penis enters the female body through the vagina, a canal that connects the external genitalia (labia majora and minora and the clitoris) with the uterus.

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immune system

The immune or immune system is the person in charge of the organization's defense identifying, chasing and eliminating foreign bodies and substances that may penetrate it. To do this, it has a series of organs that produce white blood cells (lymph nodes, spleen, thymus and bone marrow) of different types: cells specialized in discovering, attenuating and expelling potentially harmful agents, such as bacteria, viruses, etc.

These white blood cells or lymphocytes move through the human body through the tegument and the lymphatic system, as well as blood and other fluids. When they find a sign of infection or poisoning, they trigger the body's alerts and do everything possible to isolate and expel the intruder either through the excretory or digestive system, or even through secretions such as pus or mucus, which emerge from mucous membranes or infected regions, as the case may be.

locomotor system

The locomotor system is the union of the muscular apparatus and the skeletal apparatus which are composed respectively of the almost 650 muscles of different sizes and shapes that allow the mobilization of the body, and the 206 bones also of different shapes and sizes that support the body and serve as protection for the internal organs.

Thanks to these two systems the human body retains its shape and posture and can also move or move its limbs at will, which is essential for life.