The human body is made up of 37 trillion cells, What are the unit of life.
It is not surprising that we find a great diversification between them to be able to perform different functions, allowing to supplement and cover the vital needs of an organism, such as the maintenance of body structure, nutrition and respiration. It is estimated that there are about 200 types of cells that we can distinguish in the organism, some more studied than others.
Throughout this article, we will talk about the main categories that group cell types according to their characteristics.
Why are these microscopic bodies important?
Although our mental processes seem to originate from a point far from our head where the connection between soul and body is established, as the philosopher Descartes believed, the truth is that they are explained primarily by the relationship between the human organism and the environment in which it lives. This is why we know the types of cells that we are composed of it helps to understand how we are and how we experience things.
As you can imagine, we won’t talk about each of them, but we will do some general brushstrokes on some of them to get to know our body better.
Classify cell classes
Before starting, it would be ideal to group the cell types together to better organize the topic. There are several criteria to distinguish the different types of cells.
For the case that concerns us (human cells), we can classify them according to the group of cells to which they belong, that is to say in what type of tissue they are found.
The human body is made up of four different types of tissue, thanks to which we can keep the different environments relatively isolated from each other. that our body needs to function. These fabric categories are as follows:
- epithelial tissue: Configures the superficial layers of the body. In turn, it can be divided between coating and glandular.
- connective tissue: It acts as a connection between tissues and shapes the structure of the body. Bones, cartilage and blood are the most specialized tissues in the conjunctiva.
- muscle tissue: As its name suggests, it is made up of the grouping of cells that make up muscles.
- nerve tissue: Composed of all the elements that make up the nervous system.
1. Epithelial tissue cells
In this group we find the cells that are part of the outermost layers of the body. It is subdivided into two types that we will see below with their basic characteristics.
1.1. Upholstery fabric
It is the layers themselves that cover the body.
Epidermal or keratin cells: Cells that make up the skin. They are placed in a compact manner and are held tightly together, to prevent the entry of external agents. They’re high in keratin fibers, which kills them as they move up to the outermost part of the skin, so when they reach the outside they’re hard, dry, and heavily compacted.
Pigmented cells: This type of cell is what gives color to the skin thanks to the production of melanin, which acts as a protector against solar radiation. Problems in these cells can cause many skin and vision problems, for example, as in certain types of albinism.
Merkel cells: These cells are responsible for providing us with the sense of touch. They are interconnected with the nervous system to transmit this information to the brain.
pneumocytes: Located in the alveoli, their function is to connect the air collected in the lungs with the blood, to exchange oxygen (O2) for carbon dioxide (CO2). Thus, they are at the beginning of the sequence of functions responsible for transporting oxygen to all parts of the body.
Papillary cells: Cells found in the language. They are the ones that allow us to have a sense of taste, thanks to the ability to receive chemicals and turn that information into nerve signals, which make up taste.
enterocytes: Smooth intestinal cells, responsible for absorbing digested nutrients and transmitting them to the blood to be transported. Its function is therefore to make the wall function permeable to certain nutrients and insurmountable to other substances.
endothelial cells: They are the ones which configure and structure the blood capillaries, allowing the good circulation of the blood. Errors in these cells can damage cells of very important organs, which would stop functioning and in some cases could lead to death.
gametes: These are the cells involved in fertilization and the formation of the embryo. In women, it is the ovum and in men, it is the sperm. These are the only cells that only contain half of our genetic code.
1.2. glandular tissue
Groups of cells that share the function of generating and releasing substances.
Sweat gland cells: Types of cells that produce and expel sweat to the outside, primarily to reduce body temperature.
Lacrimal gland cells: They are responsible for generating the tear, but do not store it. Its main function is to lubricate the eyelid and slide it correctly over the eyeball.
Salivary gland cells: Responsible for the production of saliva, which facilitates the digestion of food and, at the same time, is a good germicidal agent.
hepatocytes: Belonging to the liver, they perform various functions, including the production of bile and the energy reserve of glycogen.
calciform cells: Cells in various parts of the body, such as the digestive or respiratory system, which are responsible for generating “mucus”, a substance that acts as a protective barrier.
pallet cells: Located in the stomach, this class of cells is responsible for the production of hydrochloric acid (HCl), responsible for good digestion.
2. Connective tissue cells
In this category we will find the types of cells that are part of the connective and structural tissue of the body.
fibroblasts: These are large cells that are responsible for maintaining the entire structure of the body through the production of collagen.
macrophages: Types of cells found along the periphery of connective tissue, especially in areas at high risk of invasion, such as at entrances to the body, with the function of phagocytizing foreign bodies and presenting antigens.
Lymphocytes: Commonly grouped together in leukocytes or white blood cells, these cells interact with the antigens indicated by macrophages and are responsible for generating a defense response against them. They are the ones that generate the antibodies. They are divided into T and B types.
monocytes: They are the initial form of macrophages but, unlike them, circulate in the blood and are not installed in a specific location.
Eosinophils: This is a class of leukocytes that generate and store different substances used to defend against a parasitic invasion by a multicellular organism.
Basophils: White blood cells which synthesize and store substances that promote the process of inflammation, such as histamine and heparin. Responsible for the formation of edema.
mast cells: A class of cells that produce and store large amounts of substances (including histamine and heparin) that release them as a defensive response, helping other cells in the immune system.
Adipocytes: Cells that are located throughout the body and have the ability to capture fat primarily for energy storage.
Chondroblasts and chondrocytes: They are responsible for the formation of the tissue called cartilage. Chondroblasts produce chondrocytes, the function of which is to produce components necessary to form cartilage.
Osteoblasts and Osteocytes: Cells responsible for the formation of bones, generating the process of calcification and therefore conditioning the process of growth and maturation of people. The difference between the two is that the osteoblast is the initial stage of an osteocyte.
red blood cells: Also known as erythrocytes, this type of cell is the main one in the blood, carrying O2 to the cells and extracting CO2 to the lungs. They are the ones that give the distinctive color of the blood to contain the protein hemoglobin.
Platelets or thrombocytes: Small cells that activate when a blood vessel has been damaged and must be repaired to prevent blood loss.
3. Muscle tissue cells
In this group we find only one type of cell that structures the muscles, responsible for the mobility of the body.
- Muscle fibers or myocytes: The main cell that makes up muscles. They are elongated and have the ability to contract. Muscle fibers can be differentiated between skeletal striae, which allows us voluntary control of the body; cardiac striatum, involuntary and is responsible for keeping the heart moving; and soft and involuntary in nature that controls the activity of other internal organs, such as the stomach.
4. Nerve tissue cells
Finally, in this category are the cells that are part of the nervous system.
neurons: This class of cells is the main one in the nervous system, whose function is to receive, conduct and transmit nerve impulses.
- To learn more about the subject, you can read the article “Types of neurons: characteristics and functions”.
- Neurology: Set of cells whose function is to support neurons, as protection, isolation or means of movement, mainly.
- the inconvenients: Cells located in the retina, which capture light at high intensity, providing a feeling of daylight. They also allow us to differentiate the colors.
- The sticks: Cells that work in conjunction with those before the retina, but capture low intensity light. They are responsible for night vision.