Question

Which one of the following membranes secretes a watery fluid that lubricates and cushions the joint?
a. Tendons
b. Ligaments
c. Cartilage
d. Synovial membrane

Answer 1

When the bones rub together, it will cause pain because it destroys the surrounding joints which make it difficult to move due to the high amount of friction buildup. Joint lubrication helps in decreasing the friction between the cartilages and allows painless joint movements.
The smooth tissues, synovium and synovial fluid cushion the joints so that the bones do not rub together.

Complete answer:
- Tendon is a fibrous connective tissue that is made of collagen. It connects the muscle to bone. They can be found in each muscle. The largest tendon in the body is the Achilles tendon.
- Ligaments are also fibrous connective tissues that are formed by collagen which connect the bones with other bones. The human body contains around 900 ligaments.
- Cartilage is a smooth elastic tissue that covers and protects the ends of long bones at the joints. It is much stiffer and less flexible compared to the muscle. The cartilage does not contain any blood vessels or nerves.
- Tendons, cartilages and ligaments do not secrete any fluid for the purpose of lubrication in joints.
- Synovial membrane is a layer of connective tissue that lines the cavities of joints. It secretes synovial fluid which helps in the lubrication of joints. The synovial fluid is clear and colorless under normal conditions.

The synovial membrane secretes a watery fluid that lubricates and cushions the joint.
Hence, the correct answer is option (D).

Note: The color and clarity of the synovial fluid changes under different medical conditions such as gout. Carrying too much weight and aging can cause wear and tear of the cartilages. Damage to the joints will cause arthritis. Exercising regularly can prevent such damages.