Skeletal System & Articulations

What is the function of osteoblasts?

They build bone by secreting bone matrix (osteoid).

What is the function of osteoclasts?

They break down bone by dissolving bone matrix (bone resorption).

What type of cartilage is the epiphyseal plate made of?

Hyaline cartilage — allows for longitudinal bone growth.

What happens to the epiphyseal plate after puberty?

It ossifies and becomes the epiphyseal line.

What type of joint is the knee?

A hinge joint, allowing movement in one plane (flexion and extension).

What type of joint allows rotation, like the atlas and axis vertebrae?

A pivot joint.

What type of joint is the shoulder or hip?

A ball-and-socket joint, allowing movement in multiple directions.

What vitamin is essential for calcium absorption in bones?

Vitamin D — helps the intestines absorb calcium.

What hormone raises blood calcium by stimulating osteoclasts?

Parathyroid hormone (PTH).

What hormone lowers blood calcium and promotes bone building?

Calcitonin, released by the thyroid gland.

What is the outer layer of bone called?

The periosteum — a dense connective tissue covering bone.

What is the name of the bone shaft?

Diaphysis.