Non-nuclear human cells

Everyone knows that the person is eukaryotic. This means that all cells have the organelle, which is all the genetic information, the nucleus. However, there are exceptions. Is there in the human body-cells and what is their value for life?

Non-nuclear human cells

They can not be compared with the prokaryotes, possessing the typical structure. What kind of non-nuclear cells? No nucleus in red blood cells - erythrocytes. Instead of the organelles they contain complex chemical complex substances that allow them to perform crucial to the body's functions. Platelets - platelets, and lymphocytes - also nuclear-free cells. The kernel is not in cells, called stem. All these structures brings together another sign. Because they have no nucleus, they are not able to reproduce. This means that non-nuclear cells, examples of which were given after fulfilling its function are dying, and new ones formed in specialized organs.

Red blood cells

They determine the color of our blood. Nuclear-free blood cells red blood cells have an unusual shape - a biconcave disk, which greatly increases their surface at a relatively small size. But the number of them is simply amazing: in 1 sq. mm of blood is them to 5 million! The average red blood cell lives up to four months, then dies and neutralized in the spleen and liver. New cells are formed every second in the red bone marrow.

Red blood cells

What is the kernel contain these non-nuclear cells? These substances are called heme and globin. The first is iron. It not only colors the blood red, but also forms an unstable compound with oxygen and carbon dioxide. Globin is a substance of protein nature. In its large molecule immersed gem that contains a charged iron ion. The mechanism of action of these cells can be compared with taxis. In the lungs they attach to the oxygen. The bloodstream it is carried to all cells and is released there. With the participation of oxygen the process of oxidation of organic substances to produce a certain amount of energy that a person uses to implement the activity. The vacated space is immediately carbon dioxide, which moves in the opposite direction - into the lungs where it is exhaled. This process is a necessary condition of life. If oxygen is not supplied to the cells, they were gradually withering away. It can be dangerous for the life of the organism as a whole.

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Red blood cells have another important function. Their membranes is the protein marker, called the RH factor. This indicator, like blood, is very important during blood transfusion, pregnancy, transplantation or surgical operation. It is definitely set because of incompatibility may occur the so-called rhesus-conflict. He is a defensive reaction, but can lead to rejection of the fetus or organs.

Poor nutrition, bad habits, polluted air can cause destruction of red blood cells. The result is a serious disease that is called anemia, or anemia. The person feels dizziness, weakness, shortness of breath, noise in the ears. Oxygen deficiency has a negative impact on physical and mental human activities. It is especially dangerous during pregnancy. If through the umbilical cord to the fetus not getting enough oxygen, it can lead to serious disturbances in its development.

Build platelets

A nuclear-free cells platelets also called blood plates. In the inactive state they do have a flat shape resembling a lens. But the damage to the blood vessels swell they are rounded and form irregular growths of the outer layer of the pseudopodia. Platelets are formed in red bone marrow and live long - up to 10 days, obezvrezivate in the spleen.

The Process of thrombus formation

The matrix platelets contains an enzyme called thromboplastin. In violation of the integrity of blood vessels, he finds himself in plasma. Under its influence blood protein prothrombin into its active form, in turn, acting on fibrinogen. The result is that the substance passes into the insoluble condition. It is converted into the protein fibrin. His threads are closely intertwined and form a clot. Protective reaction of the blood clotting prevents blood loss. However, the formation of a thrombus inside the vessel is very dangerous. This can lead to rupture and even death of the organism. Violation of the process of clotting is called haemophilia. This is a hereditary disease characterized by an insufficient number of platelets leads to excessive loss of blood.

Stem cells

These non-nuclear cells are called stem not in vain. They really are the basis for all others. They are also called "genetically pure". Stem cells are found in all tissues and organs, but most of them contain bone marrow. Theyhelp restore integrity where it is needed. Stem turn into any other cell types in their destruction. It would seem that if there is such a magical mechanism people should live forever. Why is this not happening? The thing is that with age the intensity of differentiation of stem cells is significantly reduced. They have been unable to restore the destroyed tissue. But there is another danger. There is a high probability of turning stem cells into cancer, which will inevitably lead to the death of any living organism.

Non-nuclear cells: examples and distinctions

The nature of non-nuclear cells are fairly common. For example, prokaryotic blue-green algae and bacteria. But, unlike a nuclear-free cells, they do not die after fulfilling their biological role. The fact that prokaryotes have genetic material. Therefore, they are able to divide, which occurs by mitosis. The result is two genetically identical of the parent cell. The genetic information of prokaryotes represented by a circular DNA molecule that doubles before dividing. The analogue of the kernel is also called nucleoid. In plants, nuclear-free are living cells of the conducting tissue - sieve tube.

So, a non-nuclear human cells unable to divide, so they exist for a short period of time to perform its function. After that is their destruction and intracellular digestion. These include corpuscles (erythrocytes), platelets (platelets) and stem cells.