Question

Ends of long bones are covered with
A. Cartilage
B. Muscles
C. Ligaments
D. Blood cells

Answer 1

Hint: Bones are rigid calcified structures that provide a framework for the body. They function to protect the soft organs of the body, produce blood cells, help in movement and act as a mineral reserve. A soft tissue protects the ends of bones that are articulated with other bones at joints.

Complete answer:
Option (a) is correct. Cartilages are soft protective covering at the ends of long bones. The tissue is composed of cells called chondrocytes. These cells contain high amounts of elastin in their ground substance and a collagenous matrix. However, cartilages are devoid of blood vessels or nerves. Cartilages serve as a shock absorber, reducing the friction that can occur between bones at a joint and providing flexibility to joints during movement.
Option (b) is incorrect. Muscles are composed of muscle cells called myocytes. Muscle tissues are soft tissues that contain proteins actin and myosin, which contract together to change length and shape of the cell. Muscle tissues are capable of being excited by electric stimulation. Muscles help in movement of body parts, heartbeat, peristalsis and locomotion. Muscles also support bones and other structures of the body.
Option (c) is incorrect. Ligament is a type of connective tissue that helps to connect bones with bones. Ligaments are composed of dense fibres called fibrocytes. They are primarily composed of collagen fibres and are resistant to damage. Ligaments tend to return to their original shape when extended to a certain point. However, if extended beyond a point, they cannot get back to their original shape and as a result, the joints are weakened.
Option (d) is incorrect. Blood cells are constituents of blood. Blood cells arise from haematopoietic stem cells in the bone marrow. There are three types of blood cells – red blood cells, white blood cells and platelets. It serves a variety of functions like carrying oxygen, imparting immunity and helping in coagulation.

Hence, the correct answer is option (A).

Note: Long bones are the bones whose length exceeds its width. Typical long bones of our body include tibia, fibula, radius, ulna, femur. The ends of these bones are covered with soft tissues called cartilages. Cartilages help to reduce friction and abrasion of the articulated bones. It also gives flexibility during movement of the bones.