What is known about the human body? How many cells are in an adult's body? How do they grow and develop, what are they intended for? All over the world, scientists are trying to solve these riddles.
What is a cell?
Ученые изучают организмы растений, животных, people. The cell is the smallest part of any organism. There are a lot of them in the human body, more than 100 trillion. The exact number is unknown. How many cells in the human body die daily? The amount depends on the destination. For example, in the intestinal epithelium - 70 billion per day, blood - 2 billion, and the cells of the nervous system do not recover after dying.
For the first time about cells learned in 1665, Robert Hook. He realized that the more mature a person, the more these structural elements in his body. It’s impossible to count how many cells are in the human body, because they die off and are born every minute.
Structure and functions
It is impossible to say how many cells are approximately in the human body, but scientists know for sure that they have a complex structure.
- nucleus, it is called the heart of the cell;
- cytoplasm;
- nucleoli;
- mitochondria;
- shell shell;
- endoplasmic reticular formation;
- ribosomes;
- lysosomes;
- dimples and pores;
- cell membrane, which provides integrity, regulates intracellular balance.
Functions associated with the synthesis of substances.Glandular cells produce hormones or enzymes. The mammary glands produce milk, the pancreas produces insulin. Some do not synthesize anything, such as muscle cells.
Regardless of how many cells in the human body, without it, they will not survive. Cells, as elements of a mosaic, make up a single organism.
Blood cells
What is the fluid that flows through the veins of people? It contains plasma and cellular elements:
- red blood cells - red blood cells;
- platelets;
- white blood bodies - leukocytes.
Their content depends on the density and color of blood. It carries the transport of chemicals through the body. In the body of an adult about 50 billion blood cells. This is about 5.5 liters.
Pigment cells
Melanocytes in the human body are responsible for colorskin, hair, eyes and some internal organs. Such cells contain pigments in the cytoplasm causing their action. Melanocytes also perform a protective function against ultraviolet rays, which are responsible for tanning. The cells are woody in appearance.
Cells of the nervous system
This is one of those that are not restored afterdying away. Their scientific name is neurons. Their task is to process and transmit information using the electrical impulses they produce. Neurons are divided into several types:
- sensory (responsible for the reaction to light, sound);
- motor;
- interneurons.
The structure includes the cell body, dendrite, axon. According to their structure, they are also divided into several groups. Human nervous system contains about 10 billion neurons. Every year about 10 thousand die and are no longer restored. The older the person, the less they remain.
Sex cells
How many cells in the human body are responsible forbreeding? They are two species, they are divided into male - sperm - and female - eggs. The male germ cell is much larger in size than the female, as it contains a greater amount of cytoplasm. They were first discovered in 1677, and the terms themselves appeared at the beginning of the 19th century.
Although it is impossible to say exactly how many cells are in humans, scientistsstudied almost all of their species. Their participation is directly related to the existence of all life on planet Earth. Scientists are trying to learn how to grow human cells on their own in research laboratories. Perhaps they will succeed.
