Question

Which of the following is a sesamoid bone?
A. Pelvis
B. Patella
C. Pterygoid
D. Pectoral girdle

Answer 1

A bone is a rigid organ that makes up part of the skeletal system in animals. Their function is to protect the various organs of the body, provide structural support to the body, and mobility. These can be of different types according to their size, structure and due to their attachment also.

Step by step answer: The human skeletal system is made up of five types of bones are-
• Long-These includes the bones of lower limbs(leg bones) and upper limbs(arm bones) and they support the body weight.
• Flat- These include the cranium bones, Sternum, Ribs, Scapulae, and Pelvis. They protect the internal organs.
• Short- These include Carpals(in wrist) and Tarsals(in ankle joints). They provide stability.
• Irregular-These have complex shapes.
• Sesamoid- A sesamoid bone is a bone that is embedded within a tendon or a muscle. It is derived from the Latin word sesamum which depicts the small size of most sesamoids. The formation of these bones takes place in response to strain or can be present as a normal variant. The largest sesamoid bone in the body is the kneecap which is also known as Patella. These bones act like pulleys as they provide a smooth surface for tendons to slide over each other and thus increasing the tendon’s ability to transmit muscular forces to act. This bone is a small nodular bone commonly present embedded in tendons in the thumb portion. As a person matures, calcification takes place.
Hence, calcification of sesamoid bone is one of the important features of puberty, which is earlier
in females than in males. Its absence indicates a delay in a pubertal growth spurt.
Hence option B is correct.

Note: Bones of the pectoral girdle contain the scapula and clavicle(long bone). Pterygoid bone is a flat bone and is a part of the sphenoid bone that is present in the skull. The smallest bone in the human body is the Stapes which is present in the middle ear and is a part of the ossicles.