Question

What are the four levels of organisation in the human body?

Answer 1

The level of organization in the human body are four and they are as follows:

• Cells

1. Cells are the structural and functional unit of life.
2. Humans are formed by eukaryotic cells which are of different types.
3. In the human body, each cell has got a different function and it is important for the cell to perform that function at the optimum level.
4. For example, neurons carry out the conduction of impulses, epithelial cells carry out the function of covering, heart cells carry out the function of the beating of the heart, etc.

• Tissues

1. Tissues are next in the level of organization and are formed by the combination of similar types of cells.
2. For example, epithelial cells combine to form epithelial tissue of various types such as cuboidal epithelial tissue, and columnar epithelial tissue.
3. Muscle cells combine to form the muscles of the body which are required for movement and other actions.

• Organs

1. Various tissues combine to form an organ.
2. For example, various heart cells combine to form the cardiac tissue and these cardiac tissues combine to form the entire heart.
3. In a similar way nephrons which are the kidney cells combine to form nephrotic tissue and later on the entire kidney.

• Organ systems

1. Some organs combine to form the entire organ system.
2. For example, the heart and blood vessels combine to form the cardiovascular system.
3. In a similar way stomach, intestine, and colon combine together to form the gastric system.