Page 1 - 2. Lesson Notes-Joints

SAI International School
Subject – Biology, Class-VI
Topic- Movements in the body
Subtopic-Joints
Module-23
Lesson notes
JOINTS
• Joints allow movement in our body.
• A joint is a place at which two bones meet and are joined together.
• It makes our body flexible.
• Ligaments- join two bones which are held together by strong and elastic bands.
• Cartilage-
❖ It is a tissue that prevents the bones from rubbing against each
other.
❖ It acts as a cushion between the two bones at a joint.
❖ The soft part of our nose and ears are also made up of cartilage.

CATEGORIES OF JOINTS-
Based on the extent to which the joints allow movement, the joints are divided into three
categories-
a) Immovable or fixed joints
• Do not allow any movement at all.
• Present in the skull.
b) Slightly movable joints
• Allow only bending and rotation.
• Present between the vertebrae of the backbone.
c) Freely movable joints
• Allow movement in all directions.
• These are of four types- ball and socket joints, hinge joint, pivot joint, and
gliding joint.

TYPES OF FREELY MOVABLE JOINTS
These are of four types-
1. Hinge joint
2. Ball and socket joints
3. Pivot joint
4. Gliding joint

1. Hinge joint

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