Which of the following is NOT a type of joint?

The correct answer is that "Layered" is not a type of joint. In human anatomy, joints are classified into several types based on their structure and the movements they allow.

Ball-and-socket joints, such as the shoulder and hip joints, allow for a wide range of motion in multiple directions. Saddle joints, like those found in the thumb, enable movement in two planes, allowing for greater flexibility and range than a hinge joint. Hinge joints, such as the knees and elbows, allow for movement primarily in one direction, similar to the action of a door hinge.

In contrast, "layered" does not refer to any recognized joint type in the field of anatomy. It does not correlate with any specific structure or function associated with joints. Understanding these classifications helps in studying how movement occurs in various parts of the body, as each joint type is adapted to meet different functional requirements.