An introduction to the 5 functions of the Skeletal System and the 4 forms of bone.

1. The Skeletal SystemThe Skeletal System
In this slideshow, you will learnIn this slideshow, you will learn
about theabout the 5 functions5 functions of bone,of bone,
and theand the 44 formsforms of bone in theof bone in the
human body.human body.

2. Deep in our body, underneathDeep in our body, underneath
our skin, muscles, and organs,our skin, muscles, and organs,
there are bones.there are bones.
In each human body there areIn each human body there are
approximately 206 bonesapproximately 206 bones..
The exact number varies fromThe exact number varies from
person to person, and alsoperson to person, and also
depends on the person’s age.depends on the person’s age.

3. Each bone in a living body is anEach bone in a living body is an
organ, made of a collection oforgan, made of a collection of
different types of tissues. Some ofdifferent types of tissues. Some of
the tissues are rigid (hard) andthe tissues are rigid (hard) and
some of them are elastic (flexible),some of them are elastic (flexible),
making bone both strongmaking bone both strong
and durable.and durable.

4. Bone has fascinated humans sinceBone has fascinated humans since
the beginning of time, probablythe beginning of time, probably
because it is the part of us that canbecause it is the part of us that can
last many, many yearslast many, many years
past our death.past our death.

5. Artist Leonardo
DaVinci made these
drawings in the early
1500s.
(Notice that he was
left-handed and wrote
in “mirror” style,
backwards from right
to left.)

6. In some European churches, there are entire chapels built of
human bones, called ossuaries. These are most common in
places were land was too important or scarce to use it for
cemetaries. So people were buried for 1-3 years, then then
their bones were dug up and added to the collection

7. The Skeletal System:The Skeletal System:
FunctionsFunctions

8. 1. Support1. Support
•The skeleton is the supporting
framework for the body
•All softer tissues hang off this frame

9. 2. Protection2. Protection
• Bony “boxes” and “cages” protect
delicate structures
For example: The skull protects the
brain and the rib cage protects the
heart and lungs.

10. 3. Movement3. Movement
• Muscles are attached to bones. As
muscles contract and shorten, they
pull on bones and move them.

11. 4. Storage4. Storage
• Bones are important in maintaining
homeostasis of blood calcium.
(Calcium is needed for normal nerve
and muscle function)
• Bones are our calcium “bank”.

12. 5. Hemopoiesis5. Hemopoiesis
• This word describes the process of
making new blood cells
(hemo = “blood”)
• Blood cells are made in the red bone
marrow inside some of our bones

13. The Skeletal System:The Skeletal System:
FormsForms

14. There are four types of bones:

15. 1. Long Bones1. Long Bones
These are longer than they are wide.
Example: The humerus (upper arm bone),
or femur (thigh bone)

16. 2. Short Bones2. Short Bones
These are little boxy bones that are sort of
square.
Example: The carpals, or wrist bones.

17. 3. Flat Bones3. Flat Bones
These are plate-like bones.
Examples: The frontal bone at the front of the
skull, or the scapula (shoulder blade) below.

18. 4. Irregular Bones4. Irregular Bones
These are a very uneven shape with lots of
bumps, holes, etc.
Example: The vertebrae, or bones of the
spine.

19. Did you know that the mostDid you know that the most
musical bone is a trom-bone?musical bone is a trom-bone?

20. Did you find my joke humerus?
The End.The End.