Question

Pivot joint occurs in:
(A) The hip and shoulder joint
(B) Between the atlas and the odontoid process of axis
(C) Sternoclavicular joint
(D) Temporomandibular joint

Answer 1

Hint: In a vertebrate anatomy, pivotal joint, also called trochoid joint or rotatory joint which permits only rotatory movement on a single axis. This joint is freely moving.

Complete answer:
Both the hip and the shoulder are ball and socket joints with a cartilage, ligaments and a labrum.
Axis has a mechanism known as the Odontoid process that rotates atlas. The joint from the atlas to the axis is referred to as a pivot joint. The head can be rotated side by side due to this joint.
The sternoclavicular joint is a synovial saddle connecting the sternum to the clavicles. It is the only real joint that connects the upper limb's appendicular skeleton to the trunk axial skeleton.
Two joints which connect the jawbone to the skull are temporomandibular joints (TMJ). The name derives from these bones: it is a bilateral synovial articulation between the skull's temporal bone above and the mandible beneath.

Hence, the option (B) is the correct choice.

Additional Information:
Uniaxial joint, which refers to a circular end of one bone, is the "sleeve" ring consisting of another bone (and probably ligaments). Uniform rotation of a single bone along its long-axis is the only permissible movement. One example is the intersection of the atlas with the axis dense, which causes the head to turn to signify 'not' side by face. Another example is the proximal radius joint, where a ringed ligament secured to the ulna is rotated in the center of the radius.

Note: A pivot articulation is found between the ring formed by the anterior arch and the transverse ligament of the atlas and odontoid process of the axis.