The Basics (Definition)
Levels of OrganizationLn
Organ System
100

The study of body structure and form

What is Anatomy?

100

The smallest level in the hierarchy of organization.

What is an Atom?

100

This system includes the skin, hair, and nails.

What is the Integumentary System?

200

The study of body function.

What is Physiology?

200

A group of similar cells performing a common function.

What is Tissue?

200

This system's main function is gas exchange

What is the Respiratory System?

300

The study of tissues.

What is Histology?

300

The number of organ systems found in humans.

How many is 11?

300

The thymus, spleen, and tonsils are organs of this system.

What is the Lymphatic System?

400

This subdivision of anatomy focuses on structures too small to see with the naked eye

What is Microscopic Anatomy?

400

This level of organization is positioned between the organelle and the tissue.

What is the Cell?

400

This system secretes hormones to regulate growth, metabolism, and reproduction.

What is the Endocrine System?

500

The study of abnormal functions caused by disease.

What is Pathophysiology?

500

This characteristic of living things involves the use and conversion of energy

What is Metabolism?

500

This system is responsible for hematopoiesis (blood cell production) and mineral storage.

What is the Skeletal System?