Ch. 27 levels of organization

Introduction to Anatomy and Physiology

Levels of Organization

Anatomy –◦The study of the structure of an organism and its parts Ex. Studying the bones in a duck

wing

Physiology – ◦The study of the structures function. What the structure does and

how it does it Ex. How a chicken wing moves to

help the duck fly.

The human body has 5 levels of organization.

Cells

◦Tissues

Organs

Organ systems

Organism

Smallest

Largest

Cells◦The basic unit of life

Tissue◦A group of cells working together to perform a specific function Ex. Muscle Tissue

Organ◦A group of tissues working together to perform a specific function Ex. Liver

Organ System◦Several organs working

together to perform a specific function Ex. Digestive System

Organism◦A living thing!◦When several organ

systems work together Ex. A cat

If you weren’t sick of these already...

Cells!What kind of cells make up the human body?

Prokaryotic or Eukaryotic

What kind of Eukaryotic Cells?Plant or Animal

But do all our cells look like this? NO

!

Specialized CellsAll organisms start out as a

single cell◦Unicellular organisms stay as a

single cell that performs all of it’s life functions

As the cell divides, the new cells differentiate and become specialized cells. ◦This means they develop a specific

shape and specific function

For exampleSome cells become red blood

cells which lose their nucleus to have more space to carry oxygen to different parts of your body.

Some cells become neurons which are nerve cells. They grow long extensions to send messages around your body

Some cells become liver cells which produce special enzymes to break down toxins