Which type of joint connects the bones of the fingers to the metacarpals?

• A. Interphalangeal joints
• B. Metacarpophalangeal joints
• C. Cylindrical joints
• D. Saddle joints

Answer: (B)

The type of joint that connects the bones of the fingers to the metacarpals is known as the metacarpophalangeal joint. These joints are crucial as they allow for the flexion, extension, and some degree of abduction and adduction of the fingers. Each finger has a metacarpophalangeal joint where the proximal phalanx of the finger articulates with the head of the corresponding metacarpal bone.

In contrast, interphalangeal joints are located between the individual phalanges of the fingers, and they allow for bending and straightening within the fingers. Cylindrical joints and saddle joints refer to other types of joint mechanics. Specifically, cylindrical joints enable rotation and are seen in places such as the elbow, while saddle joints allow for a greater range of movement in two planes, such as the thumb's basal joint with the trapezium bone. Hence, the metacarpophalangeal joint is specifically designed for finger mobility and connection to the hand’s structure, distinguishing it clearly from the other types mentioned.