Question

Which part of the body has a pivotal joint?
A. Shoulder
B. Ribs
C. Knee
D. Neck

Answer 1

Hint: Joints are formed when two bones are articulated with one another. Joints are of various types depending on their structures and functions. Pivot joints are types of joint that allow movement and rotation to a certain degree. They are found in different parts of the body.

Complete answer:
Pivot joints are synovial joints in essence. They join bones or cartilage with a capsule which continues with the periosteum of the bone. A cavity called the synovial cavity encircles the articulating surface of the bones. The synovial cavity is filled with synovial fluid and the fluid is sealed by the synovial membrane. Pivot joint joins the radio and ulna of the arm and at the base of the skull which helps to join the first and second vertebrae which help in movement of the neck.
Shoulder joint is a ball and socket joint that helps in the articulation of the upper limbs to the axial skeleton. The head of humerus articulates with the glenoid cavity of the scapula resulting in the formation of the shoulder joint. The shoulder joint allows a 360-degree rotation of the arms.
Ribs are slender bones that form a part of the rib cage in the axial skeleton. The ribs are joined to the sternum with the help of costotransverse joints. This type of joint only allows gliding movements. The rib cage protects the heart and lungs. The coordinated movement of the ribs help in the process of respiration.
Knee joint is a synovial joint. It is a compound joint made up of two joints – the tibiofemoral and patellofemoral joints. Knee functions to join the thigh with the legs. Since it is a type of synovial joint, the synovial fluid is present in the joint. Knee is the largest joint in humans. It carries the weight of the body.
Therefore, it can be concluded that a pivot joint is present in the neck.

Hence, option (D) is correct.

Note: Joints are the point of attachment of two bones. Joints are present in various parts of the body. It helps in movement of body parts. Joints can be movable or immovable. Pivot joints is a movable joint and allows movement in a single direction. Pivot joints are a modified type of synovial joint. As a result, synovial fluid is present in pivot joints. Pivot joints are present in the arm and neck. Immovable joints are present in the skull.