Level 1: Chemical. We are chemical machines with millions of chemical reactions. The body is composed of atoms bonded in various formations creating molecules and compounds.
Level 2: Cellular. Cells are made of many types of molecules. Cells are like tiny motors that keep us running. Metabolic reactions convert nutrients to cell energy called ATP.
- Level 3: Tissue. Tissues are made up of cells working together to perform the same function. The four classes are:
- - connective (cartilage, bone, tendon, blood)
- - epithelial (digestive, skin)
- - muscle
- - nerve
Level 4: Organs. An organ performs a specialized physiological function.
Level 5: Systems. An organ system is a group of specialized organs working together to acheive a specific function.
Level 6: Organism. All the systems combined make of the organism (human). The organism continuously fine tunes itself to restore balance (homeostasis). Anything that stresses the body creates a need for adaptation, meaning the cells are not working optimally at that level.