The different human body tissuesThey, with their various functions and characteristics, are all made up of the same basic, microscopic unit of life: the cell. For example: neurons, adipocytes, macrophages.
Depending on their specific role within the structural complexity of the body and therefore on their own morphology, cells can be of very different types. It is estimated that there are around 200 kinds among the 37 trillion cells that make us up.
Regarding its nature, our cells they are not that different from those of most mammals. Our animal cells are distinguished from plant cells and from mushrooms in the absence of a rigid cell wall and, furthermore, in that they do not have chlorophyll or cellulose.
A human cell typical is composed of:
- A cellular membrane permeable that allows osmosis and expulsion of material.
- A core It contains genetic information and occupies 10% of cell mass.
- A nucleolus within the nucleus, where ribosome production takes place.
- Cytoplasm, a gelatinous substance that makes up the “inside” of the cell and where all its organelles are found.
- Various organelles: the mitochondria, in charge of cellular respiration and producing energy; the vacuole, responsible for transporting substances within the cell; the ribosome, responsible for protein synthesis; the lysosome, responsible for producing enzymes; as well as a network of membranes, tubes, and bags called the endoplasmic reticulum (smooth and rough).
- You may be interested in: Organs of the human body
Examples of human cells
- Epithelial cells. They constitute cellular networks of epithelial tissue, which cover all the free surfaces of the body: ducts, mucous membranes, hollow organs, glands or the inner lining of cavities. The different layers of the skin are made up mainly of them.
- Neurons. A type of cell whose plasma membrane is endowed with electrical excitability, serving as a conductor and receptor for stimuli from the nervous system. They do not usually reproduce once they reach maturity and are vital for body control.
- Fibroblasts. The most common and less specialized cells of the body are part of the connective tissue, which maintains the integrated and sustained body structure.
- Adipocytes. Cells responsible for managing the body’s energy reserves: fats. Through enzymes they activate lipogenesis and lipolysis, processes of creation and combustion of fats respectively, and they respond especially to the hormonal circuit.
- Osteoblasts. The primary cells of the bone are responsible for forming and organizing the bone matrix, which will then be mineralized to achieve its well-known resistance. They are cuboid cells, receptors of calcium.
- Glial cells or neuroglia. The support of the neural network, they are important in the information processing of the organism. They are responsible for ionic and neurotransmitter control, serving as a kind of glue to the nervous tissue itself. They are much more abundant (1:10 to 50) than neurons.
- Macrophages. Cells belonging to the body’s immune system deal with pathogens or pollutants, as well as dead cells in the tissues that are renewed, through the phagocytization of said harmful elements. By doing this, they generate a cellular information system that triggers the immune response.
- White blood cells or leukocytes. They are a diverse group of defensive cells originated in the bone marrow and lymphatic tissue, which act against the presence of pathogenic elements in the body. There are five highly specialized types to hunt down different antigens: neutrophils, eosinophils, basophils, lymphocytes, and monocytes.
- Red blood cells or erythrocytes. They are the most numerous cells in the blood, the only ones that contain hemoglobin to carry oxygen. Unlike the rest, red blood cells are so specialized in their function that they lack nuclei and mitochondria, so that they obtain their energy through lactic fermentation instead of cellular respiration.
- Gametes. Intended exclusively for reproduction, they carry only half of the entire genome of the individual. In men, they are mobile and smaller, called sperm; in women they are larger and less mobile, called ovules.
- Canes or cotton buds. Located in the retina of the eye, they have an extreme photosensitivity, for this reason they are responsible for vision in contexts of low light presence. They are not sensitive to color.
- Cones. Unlike rods, cones are eye cells present in the retina, specialized in perceiving different wavelengths of light, thus capturing different colors from green, red and blue.
- Hepatocytes. Belonging to the liver, they are cells rich in organelles, glycogen and fat. They are responsible for secreting bile substances.
- Basal cells. Located in the outermost part of the skin, they produce the scaly layers of tissue that form the border of the body with the outside.
- Odontoblasts. They constitute the pulp of the teeth, and are responsible for producing dentin, a substance in which dental enamel is fixed.
- Peptide cells. Present in the stomach, they have the mission of secreting the hydrochloric acid necessary to form pepsin and break down ingested food.
- Goblet cells. Avocados to the production of mucus, to keep the epithelium of the respiratory tract and digestive system moist and protected. Its name comes from its inverted chalice shape.
- Pneumocytes. Pulmonary cells that line the alveolar cavity, allowing the exchange of gases with the blood and starting the respiratory circuit. There are type I and II pneumocytes, each with different morphologies and functions.
- Myocytes. They make up the muscle mass of tissue that supports the skeleton and enables strength and mobility. It has a complex network of proteins that allows it to expand and contract without losing its original shape.
- Endothelial cells. Flattened cells that line the inside of the blood vessels and the heart, constituting its outermost cell layer, in permanent contact with the blood. They also fulfill several important homeopathic functions.