Skeleton and Joints

Synovial fluid is the lubricant that allows friction-free joint movement. A synarthrosis is an immovable joint.

These concentric cylinders surround a central canal (Haversian canal) and occur in compact bone.

It is the radius and ulna bones whose movement relative to each other produce pronation and supination.

A symphysis is an immovable joint between two bones (e.g. the pubic symphysis or the mandibular symphysis). Choices A and B refer to structures within a bone. Synovium refers to the membrane that produces synovial fluid.

The fluid is synovial fluid. Amphiarthroses are “slightly moveable” joints whereas synovial joints are freely moveable.

Cartilage is avascular so the chondrocytes get their nutrients and dispose of their wastes via the synovial fluid that bathes them.

A ligament is the fibrous connective tissue that ties articulating bones together.

Phalanges are the bones of the fingers and toes. There are 14 in each hand or foot. Two in the thumb/big toe and three phalanx (phalanges) in each of the four other fingers/toes.

Red marrow is “active” marrow, in that blood cells are being formed there. Red marrow occurs in the medullary cavity as well as in the cancellous bone of the epiphyses.

A fossa is a depression into which fits a projecting part of another bone when the two bones form a joint.