1. Lesson 4 - Levels of Organization
The 5 levels of organization
tissues
Cells make up ________________?
organs
Tissues make up _____________?
organ systems
Organs make up ______________?
Organ systems make up the
_________________?
organism

2. Let’s put these 5 levels together.
Level 1 – Cells (Heart)
Level 2 – Tissues (Veins,
Arteries, Capillaries)
>
Level 3 – Organs (Heart)
Level 5 – Organism (You)
Level 4-Organ System
(Circulatory System)
>

3. 4 types of Human Tissue
Epithelial
Connective
Muscle
Nervous

4. 1st- Epithelial Tissue Closely packed cells that cover body
surfaces and the internal structures.
Examples- Skin and blood vessels

5. 2nd – Connective Tissue
Has many different
forms and functions
Ex.- Bone, Fat,
Cartilage, Blood

6. 3rd – Muscle Tissue
Contracts to allow movement.
Ex.-Heart, Biceps,
Tongue

7. 4th – Nervous Tissue
Transmits and processes information.
Ex.- Spinal Cord,
Brain, Nerves

8. The Twelve Organ Systems of the Human Body
Respiratory
Muscular
Circulatory
Skeletal
Nervous
Reproductive
Digestive
Endocrine
Immune
Excretory
Lymphatic
Integumentary

9. 1st Body System - Respiratory
Organs – Mouth, nose, pharynx,
larynx, trachea, bronchi, lungs
Function – Provides oxygen to
the body’s cells for cellular
respiration; removes carbon
dioxide as waste from the body.

10. 2nd Body System - Circulatory
Organs – Heart, blood, blood
vessels
Function – Carries oxygen and
food to the cells and carbon
dioxide away from the cells as
waste; fights infection.

11. 3rd Body System - Nervous
Organs – Brain, spinal cord,
peripheral nerves, sense organs
Function – Organizes the body’s
response to stimuli, or changes
in its internal or external
environment.

12. 4th Body System - Digestive
Organs – Mouth, pharynx,
esophagus, stomach, small and
large intestines.
Function – Breaks down food into
smaller particles that can be used
by the body’s cells for energy.

13. 5th Body System – Urinary/Excretory
Organs – Skin, lungs, kidneys,
Ureters, urinary bladders, urethra
Function – Removes waste from
the body.

14. 6th Body System - Muscular
Organs – Skeletal muscles,
smooth muscles, heart
Function – Works with skeletal
system to produce movement.

15. 7th Body System - Reproductive
Organs – Male: Produces and
delivers sperm.
Female: Produces eggs and
nourishes and shelters the
unborn baby.

16. 8th Body System - Skeletal
Organs – Bones, cartilage,
ligaments, tendons
Function – Supports the body
and protects internal organs.

17. 9th Body System - Endocrine
Organs – Pancreas, ovaries (in
females), testes (in males),
hypothalamus, pituitary, thyroid,
adrenals.
Function – Controls growth,
development, metabolism,
and reproduction.

18. 10th Body System - Immune Organs – White blood cells,
thymus, spleen, lymph nodes,
lymph vessels.
Function – Protects the body
from disease.

19. 11th Body System - Integumentary
Organs – Skin, hair, nails, sweat
and oil glands.
Function – Acts as a barrier
against infection and injury.

20. Discussion Question
Identify an activity you were involved in recently. Then
describe how at least three of your organ systems
cooperated to make the activity possible.
Review Questions
Which of the following shows the correct order of the levels of organization from
simplest to most complex?
A. organ system, organ, tissue, cell
B. cell, tissue, organ, organ system
C. tissue, cell, organ system, organ
D. organ system, tissue, cell, organ
2. A group of organ systems makes up
A. a cell.
B. an organism.
C. a tissue.
D. an organelle.
4. Which type of tissue are bones made of?
A. epithelial
B. connective
C. muscle
D. nervous
3. Which level of organization is represented by a group of different tissues that work
together to perform a function?
A. cell
B. tissue
C. organ
D. organism

21. Let’s look at a Brainpop clip to finish out Levels of Organization.
..\..\BrainPOP _ Human Body.htm