1. From Cells to Body Systems
Human Biology 11

2. Understanding Cells Cells are the building blocks of life
There are trillions of cells in the human body
Our body cells are specialized, which means that each type of cell has a different function
Each cell contains organelles which allow the cell to work properly
If the organelles do not work properly, the cell will die

3. Cells Build Tissues
Tissues are groups of specialized cells that work together to perform a certain task
There are 4 different types of tissues that are found in the human body:
Epithelial
Connective
Nerve
Muscle

4. Epithelial Tissue This tissue forms a film-like covering
Its purpose is to cover the surfaces of many different organs in the body

5. Connective Tissue This is the most common type of tissue
This separates and supports other cells and tissues
It can also act as a site of attachment for cells and other tissues
Collagen is the main protein in connective tissue

7. Nerve Tissue
This tissue is responsible for sending messages to the brain and throughout the entire body

8. Muscle Tissue This tissue is able to contract and expand
Its purpose is to allow movement

9. Tissues Build Organs
Organs are groups of specialized tissues that perform certain tasks
Each body organ has a specific shape and is made up of different types of tissues to perform a certain job
The heart, as an example, is mostly muscle tissue – WHY?
The heart also contains nerve tissue and is covered in epithelial tissue (pericardium)

10. Organs in the Human Body

11. Organs Build Systems
Body systems are groups of specialized organs that perform a specific function
Some organs belong to more than one particular body system

12. Organization of the Human Body
CELLS
TISSUES
ORGANS
BODY SYSTEMS