Levels of Organization of the Human Body

 Levels of Organization of the Human Organism

The major levels of organization in the body, from the simplest to the most complex are: atoms, molecules, organelles, cells, tissues, organs, organ systems, human organism.

The atom is the basic building block for all matter in the universe. Atom is the smallest unit of element are made up of proton, neutron, and electron.  All matter is made up of substances called elements. All elements are made up of atom.

Elements is a substance that consists of only one type of atom.

Example: oxygen) All elements are made up of atom. 

Chemical Level

Molecules a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Atoms combine to form molecules for example: water (H2O) is made up of two hydrogen atoms and one oxygen atom.

All 11 Elements are necessary for life. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life.

Cells are the basic units of life and the smallest living units of an organism. The human body is made of cell, which is made of many different molecules.

A variety of molecules combine to form the fluid and organelles of a body cell.

Cellular Level

Human cells are made of a cell membrane (thin outer layer) that encloses a jelly-like cellular fluid containing tiny organ-like structures called organelles.

• There are many types of organelles, each with a particular function for example, organelles called mitochondrion provides energy to a cell

Cells are the basic units of life and the smallest living units of an organism. The human body is made of cell, which is made of many different molecules. A variety of molecules combine to form the fluid and organelles of a body cell. For example muscle cells contract to move.

Cells in the human body are organized into tissues. A tissue is a group of similar cells that work together to perform a specific function. There are four main tissue types in humans (muscular, epithelial, nervous and connective).
An organ is a collection of tissues that form a functional unit specialized to perform a particular function for example: heart pumps blood through the blood vessels of the circulatory system.  An organ system is a group of organs that work together to perform a specific function for example: The circulatory system, also known as the
The main function of the circulatory system is to pump blood, bring oxygen and nutrients to all of the cells in the body and remove metabolic waste.  The most complex level of organization, the human organism is composed of many organ systems that work together to perform the functions of an independent individual.