Major cell types of the human body

The human body is made up of 37 trillion cells, which are the unit of life.

It is not surprising that we find a great diversification between them to be able to carry out different functions, allowing to complement and cover the vital needs of an organism, such as the maintenance of the structure bodily, The nutrition Y the breathing. 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 do these microscopic bodies matter?

Although our mental processes seem to arise from some remote point of our head where the connection between the soul and the body is established, just as I believed the philosopher Descartes, the truth is that they are explained basically through the relationship between the human organism and the environment in which it inhabits. That is why knowing the types of cells that we are composed of allows us to helps to understand how we are and in what way we experience things.

As you can imagine, we will not talk about each one of them, but we will make some general brushstrokes about some of them to get to know our body better.

Classifying the cell classes

Before you begin, it would be ideal to group the cell types to better organize your topic. There are several criteria to distinguish the different types of cells.

In the case that touches us (human cells) we can classify them depending on the group of cells to which they belong, that is, in what type of tissue they can be found.

The human body is made up of four different types of tissue, thanks to which we are able to keep different environments relatively isolated from each other that our body needs to function properly. These fabric categories are as follows:

1. Epithelial tissue: configures the superficial layers of the body. In turn, it can be divided into coating and glandular.
2. Conjunctive tissue: acts as a connection between tissues and forms the structure of the body. Bone, cartilage, and blood are the most specialized tissues of the conjunctiva.
3. Muscle tissue: As its name suggests, it is made up of the grouping of cells that make up muscles.
4. Nervous tissue: formed by all the elements that make up the nervous system.

1. Cells of epithelial tissue

In this group we find the cells that are part of the most superficial layers of the body. It is subdivided into two types that we will see below with their fundamental characteristics.

1.1. Cover fabric

They are the layers themselves that cover the body.

• Cells of the epidermis or keratinous: cells that make up the skin. They are placed in a compact way and are held tightly together, so as not to allow the entry of external agents. They are rich in keratin fiber, which kills them as they rise to the most surface of the skin, so that when they reach the outside they are hard, dry and strongly compacted.

• Pigmented cells: this type of cells is what gives the skin its color thanks to the production of melanin, which serves as a protector against solar radiation. Problems with these cells can cause many skin and vision problems, for example, as occurs 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 in the direction of the brain.

• Pneumocytes: located in the pulmonary alveoli, they have the function of bridging the air collected in the lungs with the blood, to exchange oxygen (O2) for carbon dioxide (CO2). In this way, they are at the beginning of the sequence of functions responsible for carrying oxygen to all parts of the body.

• Papilla cells: cells found on the tongue. They are what allow us to have the sense of taste, thanks to the ability to receive chemical substances and transform this information into nerve signals, which constitute flavor.

• Enterocytes: cells of the smooth intestine, which are responsible for absorbing digested nutrients and transmitting them to the blood to be transported. Its function is, therefore, to make the function of a wall permeable to certain nutrients and insurmountable for other substances.

• Endothelial cells: they are those that configure and structure the blood capillaries, allowing the correct circulation of the blood. Failures in these cells can cause cellular damage in very important organs, which would stop working properly and, in some cases, this can lead to death.

• Gametes: are the cells that participate in the fertilization and formation of the embryo. In women it is the ovum and in men it is the sperm. They are the only cells that contain only 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, mainly as a measure to reduce body temperature.

• Lacrimal gland cells: they are responsible for generating the tear, but they do not store it. Its main function is to lubricate the eyelid and make it slide properly over the eyeball.

• Salivary gland cells: responsible for producing saliva, which facilitates the digestion of food and, at the same time, is a good germicidal agent.

• Hepatocytes: belonging to the liver, they perform several functions, including the production of bile and the energy reserve of glycogen.

• Goblet cells: cells found in various parts of the body, such as the digestive or respiratory system, which are responsible for generating the "mucus", a substance that serves as a protective barrier.

• Palietal cells: located in the stomach, this class of cells are responsible for producing hydrochloric acid (HCl), responsible for proper digestion.

2. Connective tissue cells

In this category we will find the types of cells that are part of the connecting and structural tissue of the body.

• Fibroblasts: they are large cells that are responsible for maintaining the entire body structure thanks to the production of collagen.

• Macrophages: types of cells found on the periphery of the connective tissue, especially in areas at high risk of invasion, such as at the entrances to the organism, with the function of engulfing foreign bodies and presenting the antigens.

• Lymphocytes: Commonly grouped in leukocytes or white blood cells, these cells interact with the antigens indicated by macrophages and are responsible for generating a defense response against it. They are the ones that generate the antibodies. They are divided into type T and B.

• Monocytes: They constitute the initial form of macrophages but, unlike these, they circulate in the blood and are not settled in a specific place.

• Eosinophils: they are a class of leukocytes that generate and reserve different substances that are used to defend against a parasitic invasion by a multicellular organism.

• Basophils: white blood cells that synthesize and store substances that favor the inflammation process, such as histamine and heparin. Responsible for the formation of edema.

• Mast cells: class of cells that produce and reserve a large amount of substances (including histamine and heparin) that release them as a defensive response, helping the other cells of the system immunological.

• Adipocytes: cells that are found throughout the body and have the ability to capture fat as an energy reserve, mainly.

• Chondroblasts and chondrocytes: they are responsible for forming the tissue that we know as cartilage. Chondroblasts produce chondrocytes, which have the function of producing the necessary components to form cartilage.

• Osteoblasts and Osteocytes: cells responsible for forming bones, generating the calcification process and consequently conditioning the growth and maturation process of people. The difference between the two is that the osteoblast is the initial phase of an osteocyte.

• Red blood cellsAlso known as erythrocytes, this type of cell is the main one in the blood, transporting O2 to the cells and extracting CO2 to the lungs. They are the ones who give the distinctive color of the blood by containing the protein hemoglobin.

• Platelets or thrombocytes- Small cells that are activated when a blood vessel has been damaged and needs to be repaired to prevent blood loss.

3. Muscle tissue cells

In this group we only find a single type of cell that structures the muscles, responsible for the mobility of the organism.

• From muscle fibers or myocytes: the main cell that makes up the muscles. They are elongated and have the ability to contract. Muscle fibers can be differentiated between skeletal striatum, which allows us voluntary control of the body; cardiac striatum, non-voluntary and is responsible for keeping the heart moving; and smooth, 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 type of cell is the main cell of the nervous system, which has the function of receiving, conducting and transmitting nerve impulses.
  • To expand more on the subject, you can read the article "Types of neurons: characteristics and functions".
• Neuroglia: set of cells with the function of supporting neurons, as protection, isolation or a means through which to move, mainly.
• Cones: cells found in the retina, which capture high intensity light, providing the sense of daytime sight. They also allow us to differentiate colors.
• Canes: cells that work together with the previous ones in the retina, but capture low intensity light. They are responsible for night vision.