Main cell types of the human body

What are the cells that make up our body and what functions do they perform?

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

It is not surprising that we find a great diversification among them in order to carry out different functions, allowing them to complement each other and cover the vital needs of an organism, such as the maintenance of the 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 discuss 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 hidden point in our head where the connection between the soul and the body is established, as the philosopher Descartes believed, the truth is that they are basically explained by the relationship between the human organism and the environment in which it lives. That is why knowing the types of cells of which we are composed helps us to understand how we are. helps us to understand how we are and how 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 know our body better.

Classifying cell types

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

For the case we are dealing with (human cells) we can classify them depending on the group of cells to which they belong, that is, in which 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 relatively isolated from each other the different environments that our body needs to function properly. that our body needs to function properly. These tissue categories are as follows:

1. Cells of the epithelial tissue

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

1.1. Covering tissue

These are the actual layers that cover the organism.

1.2. Glandular tissue

Groups of cells that share the function of generating and releasing substances.

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.

3. Muscle tissue cells

In this group there is only one type of cell that structures the muscles, which are responsible for the mobility of the organism.

4. Nerve tissue cells

Finally, in this category are the cells that form part of the nervous system.

• Connective tissueacts as a connection between tissues and forms the structure of the body. Bone, cartilage and Blood are the most specialized connective tissues.
• Muscular tissueAs its name suggests, it is made up of the group of cells that form the muscles.
• Nervous tissueNervous system: formed by all the elements that form the nervous system.

  • Epidermal cells or keratinous cellsepidermal or keratinous cells: cells that make up the skin. They are compactly arranged and are tightly bound to each other, so as not to allow the entry of external agents. They are rich in keratin fiber, which kills them as they ascend to the most superficial part of the skin, so that when they reach the outside they are hard, dry and tightly compacted.

  • Pigmented cellsMelanin: This type of cell is what gives the skin its color thanks to the production of melanin, which serves as a protector against solar radiation. Problems in these cells can cause many skin and vision problems, for example, as occurs in certain types of albinism.

  • Merkel cellsMerkel 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.

  • PneumocytesPneumocytes: located in the pulmonary alveoli, their function is to act as a bridge between the air collected in the lungs and the blood, to exchange oxygen (O2) for carbon dioxide (CO2). They are thus at the beginning of the sequence of functions responsible for carrying oxygen to all parts of the body.

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

  • EnterocytesEnterocytes: cells of the smooth intestine, which are responsible for absorbing digested nutrients and transmitting them to the blood for transport. Their function is therefore to act as a permeable wall for certain nutrients and impassable for other substances.

  • Endothelial cellsEndothelial cells: these are the cells that form and structure the blood capillaries, allowing blood to circulate properly. Failures in these cells can cause cell damage in very important organs, which would cease to function properly and, in some cases, this can lead to death.

  • GametesGametes: are the cells that participate in fertilization and embryo formation. In the female it is the egg and in the male it is the sperm. They are the only cells that contain only half of our genetic code.

  • Sweat gland cellsSweat gland cells: types of cells that produce and expel sweat to the exterior, mainly as a measure to reduce body temperature.

  • Lacrimal gland cellsTear gland cells: responsible for generating tears, but do not store them. Their main function is to lubricate the eyelid and make it slide properly over the eyeball.

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

  • Hepatocytesbelonging to the liver, they perform various functions, including the production of bile and the energy reserve of glycogen.

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

  • Palatal cellslocated in the stomach, these cells are responsible for producing hydrochloric acid (HCl), which is responsible for proper digestion.

  • FibroblastsFibroblasts: these are large cells that are responsible for maintaining the integrity of the body's structure through the production of collagen.

  • MacrophagesMacrophages: cell types found around the periphery of the connective tissue, especially in areas at high risk of invasion, such as at the entrances to the body, with the function of phagocytizing foreign bodies and presenting antigens.

  • LimphocytesCommonly grouped in leukocytes or white blood cells, these cells interact with antigens signaled by macrophages and are responsible for generating a defense response against them. They are the ones that generate antibodies. They are divided into T and B types.

  • MonocytesThey are the initial form of macrophages but, unlike macrophages, they circulate in the blood and are not based in a specific place.

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

  • Basophilswhite blood cells that synthesize and store substances that promote the inflammatory process, such as histamine and heparin. Responsible for the formation of edema.

  • Mast cellsAdipocytes: a class of cells that produce and store large quantities of substances (including histamine and heparin) which they release as a defensive response, helping the other cells of the immune system.

  • Adipocytescells that are found throughout the body and have the capacity to capture fat as an energy reserve, mainly.

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

  • Osteoblasts and OsteocytesOsteoblasts: cells in charge of bone formation, generating the calcification process and consequently conditioning the growth and maturation process of individuals. The difference between the two is that the osteoblast is the initial phase of an osteocyte.

  • Red blood cellsErythrocytes: also known as erythrocytes, this type of cell is the main cell in the blood, transporting O2 to the cells and extracting CO2 to the lungs. They give the blood its distinctive color by containing the protein hemoglobin.

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

  • Muscle fibers or myocytesMyocytes: the main cells that make up the muscles. They are elongated and have the capacity to contract. Muscle fibers can be differentiated between skeletal striated, which allows us voluntary control of the body; cardiac striated, which is not voluntary and is responsible for keeping the heart in motion; and smooth, which is involuntary and controls the activity of other internal organs, such as the stomach.
  • NeuronsNeurons: this type of cell is the main cell of the nervous system, which has the function of receiving, conducting and transmitting nerve impulses.
    • For more information on the subject, you can read the article "Types of neurons: characteristics and functions".
  • NeurogliaA set of cells whose function is to support the neurons, mainly as protection, insulation or medium through which they move.
  • Conesretinal cells: cells found in the retina that capture high-intensity light, providing the sense of daytime vision. They also allow us to differentiate colors.
  • RodsRods: cells that work together with the previous ones in the retina, but capture low-intensity light. They are responsible for night vision.