JOINTS

A joint is a place in a body where two or more bones meet.
How is a joint adapted to a friction free movement?.
-It contains synovial fluid which reduces friction at the joint.
0-The bones are covered with cartilage at the ends.

joint

Structure of a joint.

A Tendon is a tough fibrous tissue that connects muscles to bones.
A Ligament is a fibrous elastic tissue that joins a bone to a bone.

Cartilage prevents the bone ends frictional damage after rubbing directly onto each other.
Inside a joint is a lining of synovial membrane which secretes synovial fluid.
Synovial fluid reduces friction in a joint.

Classification of joints:

Types of joints
Joints may be either Movable, immovable or slightly movable

However, the principle types of joints are: Ball and socket joints, hinge joint, pivot joint, gliding joint.

Examples of movable joints

  1. Hinge joint-It allows movement in one plane e.g. knee, elbow, knuckle
  2. Ball and socket– It allows movement in three planes e.g. shoulder, hip
ball and socket
  1. Gliding joint- They allow flat bones to slide over one another.eg wrist/ ankle
glinding
  • Pivot joint– e.g. the neck.                                                                                                               

Example of immovable joint.

Suture joints in the skull.

Questions

  1. How are joints important to a boy of 4 years?
  2. What is a joint?
  3. Write down one way joints are similar to muscles.
  4. Write down any one example of a hinge joint.
  5. Why is a shoulder joint said to be a movable joint?
  6. State the substance in the human body that helps to reduce friction.