Cytology and histology

Cytology, also called cell biology, is the science that studies the cell from a morphological (structural study) and functional (study of fundamental processes) point of view. Cytology approaches are both at the microscopic and molecular level, both in single-celled organisms and in more complex organisms such as humans.

Knowledge of the structure of the cell and the processes that take place in it is very important for all biological sciences, as it allows us to grasp the similarities and differences between cells of different organisms, or of different tissues. The information provided by cytology is fundamental in other disciplines, both molecular (such as genetics, biochemistry or molecular biology) and macroscopic (such as pathology).

The cell

The basic unit of any organism is the cell.

There are two types of cells:

  • eukaryotic: they have a complex internal structure, with a core enclosed in a membrane.
  • prokaryotic: they do not contain a defined nucleus; they have a more simplified internal composition, have been further subjected to detailed DNA analyzes and divided into two different domains, called Eubacteria (the bacteria proper) and Archaea (also called archeobacteria).

What is Histology

Histology is the discipline that studies plant and animal tissues. It is an important branch of medicine, surgery and biology. Tissues are cell types differentiated by form and function which are present only in animals and plants. Tissues are structures made up of cells similar in morphology and function, assigned to perform one or more specific tasks within the body.

Cells: classification of tissues

According to the current classification, there are four basic types of fabrics:

  • Epithelial tissue, consisting of tightly adhered cells, assigned to the lining of the internal and external cavities of the body and to the formation of the glands.
  • Connective tissue, consisting of cells immersed in a substance called extracellular matrix, and intended to structurally and functionally connect the other tissues or organs.

It differs, according to morphological or functional specifications, in various tissue sub-types:

  • loose connective tissue
  • dense connective tissue
  • cartilage tissue, which in turn can be divided into:
    • hyaline cartilage tissue
    • elastic cartilage tissue
    • fibrous cartilage tissue

bone tissue, which in turn can be divided into:

    • dense bone tissue
    • spongy bone tissue
  • fatty tissue
  • the blood
  • Muscle tissue, made up of cells called myocytes, responsible for the voluntary or involuntary movement of the organs of the body;
  • Nerve tissue, made up of cells called nerve cells or neurons, responsible for receiving and transmitting both internal and external stimuli.

These four basic tissues derive from embryonic tissues or sheets:

  • ectoderm,
  • mesoderm
  • the endoderm.

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