Question

Femur and humerus are
A) Membranous bone
B) Investing bone
C) Cartilaginous bone
D) Sesamoid bone

Answer 1

Hint:The humerus and the femur are the corresponding bones of the arms and legs. While in general, their parts are identical, their arrangement has been adapted to different functions.

Complete answer:
One that is cylindrical in shape is a long bone, being longer than it is wide. However, bear in mind that the word defines a bone's shape, not its size. In the arms (humerus, ulna, radius) and legs (femur, tibia, fibula), and in the fingers (metacarpals, phalanges) and toes (metatarsals, phalanges), there are long bones. Long bones serve as levers; as muscles contract, they shift.

The femur and humerus are bones that are cartilaginous. From a cartilage model, these bones ossify and this form of ossification is referred to as intracartilaginous ossification. These bones are not made from mesenchymal condensation, but from models of preformed cartilage. Examples of bones of this type include limb bones, vertebral column, and thoracic cage.

Cartilaginous joints (fibrocartilage or hyaline) are bound entirely by cartilage. Cartilaginous joints allow more bone mobility than a fibrous joint, but less than the synovial joint, which is highly mobile.
Identified as "synchondrosis" are main cartilaginous joints. Such bones are connected by hyaline cartilage and often occur between centres of ossification. With age, this cartilage will ossify.

The "growth plates" between ossification centres in long bones are some examples of primary cartilaginous joints in humans. These joints allow only a limited amount of movement here, such as in the spine or ribs.

Thus the correct answer is option (C) i.e, Cartilaginous bone.


Note:Cartilage has limited repair capabilities: they do not move to damaged areas because chondrocytes are bound in lacunae. Cartilage damage is also hard to repair. Also since hyaline cartilage does not have a supply of blood, new matrix deposition is slow. Damaged hyaline cartilage is normally replaced by scar tissue from fibrocartilage. In recent years, surgeons and scientists have developed a variety of procedures for cartilage repair that help to delay the need for joint replacement.