Organization of the Body

levels_of_organization

The cell is the basic functional unit of all known living organisms. The cell is the smallest unit of life that can replicate independently.

Cells group to form tissues. Tissues have a specialized functions. Examples of tissues include blood, muscle and bone.

Different tissues group to form organs. Examples of organs include stomach, liver, heart and brain.

Organs form organ systems which perform a particular function which maintains homeostasis and maintains normal health.

The digestive system is an example of an organ system. It is responsible for digesting and absorbing food. It consists of a number of organs including the stomach and intestines.

Topics in this Section

The cell: structure and functionsPlasma membraneOrganelles
Cell divisionMutationTransport of substances across cell membranes
TissuesEpithelial tissueConnective tissue
Muscle tissueNervous tissueTissue repair and regeneration
Body membranesGlandsOrganization of the body
Anatomical termsThe skeletonAxial skeleton
Appendicular skeletonCavities of the bodyCranial cavity
Thoracic cavityAbdominal cavityPelvic cavity
Disorders of cells and tissuesNeoplasms or tumorsCauses of neoplasms
Growth of tumorsEffects of tumorsCauses of death in malignant disease