The skeletal system consists of 206 bones that provide structure, protect organs, allow movement, and produce blood cells. There are four types of bones: long bones like the femur; short bones like wrist bones; flat bones like the skull; and irregular bones like vertebrae. The skeletal system works with muscles to support the body, enable movement through leverage, and shield delicate tissues.

1. Introduction
to the
Skeletal
System

2. What is the Skeletal System
The skeletal system is your body's central framework. It consists of bones and
connective tissue, including cartilage, tendons, and ligaments. It's also called the
musculoskeletal system

3. Skeletal system
The adult human skeletal system consists of 206 bones which forms
the frame of the body. However, infants are born with around 270 bones,
some of which fuses together as the body develops and matures, so by adulthood
the body would comprise of 206 bones.

4. Function of the Skeletal System
• STRENGTH, SUPPORT AND SHAPE: It gives strength, support and shape
to the body. Without a hard and rigid skeletal system, human body cannot stand
upright, and it will become just a bag of soft tissues without any proper shape.
• PROTECTION OF DELICATE ORGANS: In areas like the rib cage and
skull, the skeleton protects inner soft but vital organs like heart and brain from
external shocks. Any damage to these organs can prove fatal, therefore
protective function of skeleton is very important

5. Con…..T
• LEVERAGE FOR MOVEMENTS: Bones of the human skeleton in all parts
of body provide attachment to the muscles. These muscles provide motor
power for producing movements of body parts. In these movements the parts of
skeleton acts like levers of different types thus producing movements according
to the needs of the human body.
• PRODUCTION OF RED BLOOD CELLS: Bones like the sternum, and
heads of tibia have hemopoeitic activity (blood cells production). These are the
sites of production of new blood

6. Types of Bones
Your bones are different shapes and sizes because they have different
jobs to do. They are divided into four group:
• Long bones
• Shorts bones
• Flat bones
• Irregular bones

7. Long Bone
Long bones are mostly located in the appendicular skeleton and include bones in
the lower limbs (the tibia, fibula, femur, metatarsals, and phalanges) and bones
in the upper limbs (the humerus, radius, ulna, metacarpals, and phalanges).

8. Short Bone
• These are small squat. They are spongy bone covered with a thin layer of
compact bones. So, they are light and very strong.
• Example: the carpals of the wrist, the tarsals of the feet.

9. Flat Bone
• These are two spongy bones between two layers of compact bones.
They have large surface area,
• Examples: the scapula, pelvis, and the cranium. The scapula and pelvis
need a large area for all the muscles that attach to them. The cranium
needs a large area to protect the brain.

10. Irregular Bones
• These are spongy bones inside and compact bones outside. They are specially
shaped to suit the job they must do.
• Examples: the vertebrae

11. Example of Short Bones

12. Function of the bones
• Long bones. These mainly act as levers for a large range of movement, e .g. the very long ones (radius, ulna and
the humerus) all work together to allow you to hit a shuttlecock a long way in badminton.
The smaller bones e.g. phalanges and metacarpals, allow you to perform more delicate movement, like net shots.
People who do sports where you need to import momentum to things, often have long levers.
• Shorts bones. These provide the movement where it is needed in lots of directions but also give strength.
• Flat bones. These protect delicate organs and give a big surface area for muscle attachment.
• Irregular bones. These protect for example the spinal cord, and provide supports,

13. Example of flat Bones

14. Example of
long Bones

15. Example of irregular Bones

16. Example of
the Skeletal
System

17. Homework (graded)
1. Identify the four bones that made up the Skeletal System, and their
function .
2. Effects of physical activity on the skeletal system
3. How many bones are in the skeletal system
4. Identify the location of bones found in the human body