the human skeletal system
The Human skeletal system is the framework of bones inside our body. It gives our body shape, support, and protection.
1. Number of bones
An adult human has 206 bones in the skeletal system.
2. Main functions
The skeletal system has several important jobs:
Support: It holds the body up and gives it shape.
Protection: Bones protect important organs.
The skull protects the brain.
The rib cage protects the heart and lungs.
Movement: Bones work with muscles so we can move, walk, and run.
Making blood cells: Some bones make blood cells in the bone marrow.
Storing minerals: Bones store minerals like calcium and phosphorus.
3. Main parts of the skeleton
Some important bones are:
Skull – protects the brain
Rib cage – protects heart and lungs
Spine (vertebral column) – supports the body and helps us bend
Arm bones – help us lift and hold things
Leg bones – help us stand and walk
4. Two main divisions
The skeletal system is divided into two parts:
Axial skeleton – skull, ribs, and spine
Appendicular skeleton – arms, legs, shoulders, and hips
5. Interesting fact
The largest bone in the body is the femur (thigh bone), and the smallest bone is the stapes in the ear.
Two main divisions of the skeleton
Axial skeleton
The Axial skeleton forms the central axis of the body.
It includes:
Skull
Vertebral column
Rib cage
Its main job is to protect important organs like the Brain, Heart, and Lungs.
Appendicular skeleton
The Appendicular skeleton includes the limbs and limb girdles.
It includes:
Shoulder girdle
Arms
Pelvic girdle
Legs
This part mainly helps in movement.
2. Types of bones
There are four main types of bones in the body.
Long bones
Example:
Femur and arm bones.They help in movement.
Short bones
Example:
bones in the Wrist and Ankle.
Flat bonesExample: Skull and Ribs.They protect organs.
Irregular bones
Example:
bones in the Vertebral column.
3. Important bones in the body
Clavicle – collar bone
Scapula – shoulder blade
Humerus – upper arm bone
Radius – forearm bone
Ulna – forearm bone
Pelvis – hip bone
Femur – thigh bone
Patella – kneecap
Tibia – shin bone
Fibula – lower leg bone
4. What bones contain
Inside bones there is Bone marrow.
Bone marrow:
Makes red blood cells
Makes white blood cells
Makes platelets
These help the body carry oxygen, fight disease, and stop bleeding.
5. Ligaments and tendons
Bones connect with other parts using:
Ligament – connects bone to bone
Tendon – connects muscle to bone
These help the body move and stay stable.
6. Growth of bones
Bones grow because of Growth plate.
Growth plates are found at the ends of long bones.
They help children grow taller.
7. Common bone problems
Some problems of bones are:
Fracture – broken bone
Osteoporosis – weak bones
Arthritis – painful joints
8. How to keep bones healthy
To keep bones strong:
Eat foods rich in calcium
Drink milk
Exercise regularly
Get sunlight for vitamin D
Maintain good posture
Rib Cage
The Rib cage protects the Heart and Lungs.
Humans have 12 pairs of ribs.
Spine
The Rib Cage
The Rib cage protects the Heart and Lungs.
Humans have 12 pairs of ribs.
Arm and Leg Bones
These bones help us move, walk, run, and lift things.
The largest bone is the Femur (thigh bone).
The smallest bone is the Stapes in the ear.
What bones are made of
Bones are made of:
Calcium
Phosphorus
Bone cells
Inside many bones is Bone marrow, which makes blood cells.
4. Joints
A Joint is the place where two bones meet.
Types of joints:
Hinge joint – elbow, knee
Ball-and-socket joint – shoulder, hip
Pivot joint – neck
Joints help the body move in different ways.
5. How skeletal system works with muscles
The skeletal system works with Muscles.
Muscles pull on bones.
This allows us to walk, run, jump, and lift objects.