04 The Skeletal System Free Online FlashCards

What structures make up the skeletal system?

The skeletal system includes bones, cartilage, joints, and supporting connective tissues.

How many bones does an adult skeleton typically contain?

An adult skeleton typically contains 206 bones.

How do collagen and mineral salts contribute to bone strength?

Collagen helps bone resist pulling forces; mineral salts, especially calcium phosphate, give it hardness and help it resist compression.

What roles do osteoclasts, osteoblasts, and osteocytes play?

Osteoclasts break down bone, osteoblasts build it, and osteocytes help maintain and regulate bone tissue.

How do compact and spongy bone differ?

Compact bone is dense and forms the strong outer layer. Spongy bone is a lighter, lattice-like tissue inside bones; its spaces contain marrow and help distribute forces.

What are the shaft and expanded ends of a long bone called?

A long bone’s shaft is the diaphysis, and its expanded ends are the epiphyses.

What is the periosteum?

The periosteum is a tough, blood-vessel-rich covering that coats most of a bone’s outer surface.

How do the three structural joint types differ in mobility?

Fibrous joints allow little or no movement; cartilaginous joints allow limited movement; synovial joints permit the greatest range of movement.

What features support smooth, controlled movement in a synovial joint?

A synovial joint has a fluid-filled cavity enclosed by a capsule. Articular cartilage reduces friction, synovial fluid lubricates surfaces, and ligaments help hold bones together and limit excessive movement.

How do the shoulder and hip differ in joint function?

The shoulder permits broad movement, while the hip’s deeper, more stable joint helps support body weight.

What are the skeleton’s main functions?

The skeleton supports the body, protects organs, enables movement, stores minerals such as calcium and phosphate, and houses marrow where blood cells are produced.

How do tendons, bones, and joints work together during movement?

Tendons attach skeletal muscles to bones. When a muscle contracts, it pulls on a bone that acts as a lever, while the joint acts as a pivot.