Question

Saddle joint is present in:
(a) Human
(b) Rabbit
(c) Both of the above
(d) Frog

Answer 1

Hint: This type of joint is present in highly intelligent primates which are considered as dominant species present on the earth. According to Carl Linnaeus, they are present in mammalian order which has close relation with chimpanzees, gorillas and orangutans.

Complete step by step answer:
Saddle joint is a multi-axial joint which shows the same movement as ellipsoid joint with the addition of some rotation around the third axis. The saddle joint has a characteristic articular surface of reciprocally concave-convex. The surface of one bone fits complementary with the surface of the other bone. The saddle joints allow the movement of the joint like forward and backwards and right to left.
Example:
- Wrist joint
- First carpometacarpal joint
- Sternoclavicular joint
- Between femur and patella
So, the correct answer is, ‘Human.’

Additional information:
- Synovial or Freely moveable joints:
- This is present inside the synovial joint capsule which holds the fluid in place.
- The synovial membrane present inside the capsule where the fluid is produced.
- Types of Synovial Joints:
- Ball and Socket Joint
- Hinge Joint
- Pivot Joint
- Gliding Joint
- Saddle Joint
- Condyloid Joint
- Characteristics of Synovial joint:
- Articular cartilage/Hyaline cartilage: The part of the bone is covered with cartilage. It provides a smooth articular surface capsule and capsular ligament.
- The joint is surrounded and enclosed by a sleeve of fibrous tissue which holds the bone together.
- It is sufficiently loose to allow freedom of movement in bone but strong enough to protect it from injury.
- Synovial membrane:
- This is made up of epithelial cells and is found lining the capsule.
- The covering for those parts of the bone within the joint. Covering all intracapsular structures which do not bear weight.
- Synovial fluid:
- This is the thick sticky fluid of egg- white consistency and secreted by the synovial membrane into the synovial cavity.
- This provides nutrients for the structure within the joint cavity.
- It contains phagocytes which remove microbes.
- This acts as a lubricant.
- This helps in maintaining joint stability.
- It allows the greatest range of movement.

Note: Joint are classified into three types:
- Fibrous or fixed joints or Immovable joints: These joints are held together by tough tissue which develops during childhood.
Examples: Cranium.
- Cartilaginous or Slightly moveable joints: In this joint, the movement is needed but only to a certain point Examples: Vertebral column, Symphysis pubis
- Synovial or Freely moveable joints: These joints allow free movement to take place.