MPPSC 2022 Prelims Paper-I · Question 1 of 100

Correct — D, Synovial joint. The Atlas (C1) and Axis (C2) vertebrae articulate at the atlanto-axial joint, a pivot joint — and pivot joints are one of the freely-movable synovial joint types (fluid-filled joint cavity, articular cartilage, enclosing capsule). The odontoid process (dens) of the Axis rotates within a ring formed by the Atlas, letting the head turn side to side.

• (a)Saddle joint — A saddle joint is a different synovial sub-type (e.g. the thumb's carpometacarpal joint) that allows back-and-forth and side-to-side movement, not rotation — it is not the Atlas-Axis joint.
• (b)Fibrous joint — Fibrous joints (e.g. skull sutures) are fixed/immovable, connected by dense connective tissue with no joint cavity — the opposite of the freely-rotating Atlas-Axis joint.
• (c)Cartilaginous joint — Cartilaginous joints (e.g. between vertebral bodies via intervertebral discs, or the pubic symphysis) allow only slight movement and lack a synovial cavity — they are not pivot joints.

Joints are classified by structure into fibrous (immovable), cartilaginous (slightly movable) and synovial (freely movable). Synovial joints are further divided by shape into hinge, pivot, ball-and-socket, saddle, gliding and condyloid types. A pivot joint lets one bone rotate around another — the clearest example is the atlanto-axial joint, which lets the head rotate.

MPPSC likes to test 'name the joint type between bone X and bone Y' — the trap is treating 'pivot' as a category separate from 'synovial' when pivot is actually a sub-type of synovial. Students must know the movement (rotation) points to pivot, and pivot is always synovial.

• Atlas (C1) and Axis (C2) form the atlanto-axial joint — a pivot joint
• Pivot joints are a sub-type of synovial (freely movable) joints
• The odontoid process (dens) of the Axis rotates within the Atlas's ring, enabling head rotation
• Other pivot joint example: proximal radio-ulnar joint (forearm rotation)

• Treating 'pivot' as a category separate from 'synovial' rather than a sub-type of it
• Confusing the Atlas-Axis pivot joint with a hinge joint (like the elbow or knee)

MPPSC and UPSC-adjacent exams ask either 'name the joint type' for a named body-part pair, or ask students to match joint type to example (elbow-hinge, shoulder-ball-and-socket, Atlas-Axis-pivot).

No directly related past PYQ was found.

• practice — not a real PYQ

  Which type of synovial joint is found at the shoulder, allowing movement in almost all directions?

  • (a)Hinge joint
  • (b)Pivot joint
  • (c)Ball-and-socket joint
  • (d)Saddle joint

  Answer(c) Ball-and-socket joint — found at the shoulder and hip, allowing the widest range of motion.

• practice — not a real PYQ

  The knee joint, which allows movement in one plane like a door hinge, is an example of a:

  • (a)Pivot joint
  • (b)Hinge joint
  • (c)Gliding joint
  • (d)Fibrous joint

  Answer(b) Hinge joint — permits flexion and extension in a single plane, as at the knee and elbow.