The human body can be viewed at various levels:
The human body consists of molecules, atoms, ions, formed by various chemical elements. Carbon C, hydrogen H, oxygen O, nitrogen N are of the greatest importance for the construction of the protein structure of the body.
The human body consists of eukaryotic cells with a formed nucleus and a structure characteristic of animal cells.
Cells and intercellular substance form tissues in the human body. Depending on the type of fabric, they perform different functions, therefore they have different sizes and shapes.
Each organ is made up of tissues that share a common structure and perform similar functions. In an organ, one type of tissue always prevails.
muscle tissue predominates in the heart, epithelial tissue in the skin.
Many bodies complement each other in their functions. Thus, it is possible to distinguish systems of organs that perform general functions in the body (musculoskeletal, digestive, etc.).
Organ systems are combined into a single organism, functioning under the control of the nervous and endocrine systems.