Which component of a synovial joint is responsible for reducing friction during movement?

A. Saddle:Saddle joints allow biaxial movement (for example the thumb carpometacarpal joint) but do not provide the greatest overall range of motion.
B. Hinge:Hinge joints permit movement primarily in one plane (flexion and extension), limiting their range compared with multiaxial joints.
C. Pivot:Pivot joints allow rotation around a single axis (for example the atlantoaxial joint) and therefore have a restricted range of motion.
D. Ball-and-socket:Ball-and-socket joints permit multiaxial movement including flexion/extension, abduction/adduction, and rotation, offering the greatest range of motion.

A. Sebaceous gland: Sebaceous glands secrete sebum (an oily substance) that lubricates and waterproofs skin and hair.
B. Apocrine gland:Apocrine glands produce a protein-rich sweat (body odor after bacterial action), found in axilla/groin; not the primary source of sebum.
C. Eccrine gland: Eccrine glands produce watery sweat for thermoregulation distributed over much of the body.
D. Ceruminous gland: Ceruminous glands are modified sweat glands in the ear canal that produce cerumen (earwax), not sebum for hair/skin lubrication.