A&P 6-3.4

The process of day-to-day bone maintenance (resorption and new deposits) is termed

Remodeling

The process of healing fractured bones is called

Repair

In bone remodeling, ________ produce acids that break down calcium phosphate (demineralize the bone) and lysosomal enzymes that break down collagen

osteoclasts

_________ secrete osteoid (bone proteins) that attract and bind calcium

osteoblasts

Then osteoid is mineralized, and the entrapped cells become _______

osteocytes

More remodeling takes place in the areas exposed to more wear and tear. This may affect the overall shape of the bone(______)

Wolff's law

_______ stimulates osteoclasts resulting in bone resorption and release of calcium into the bloodstream

parathyroid hormone (PTH)

______stimulates osteoblasts, resulting in new bone formation and decrease calcium blood levels

calcitonin

Starting from puberty, _____________ also stimulate osteoblasts and bone building

estrogen or testosterone

With aging, their levels drop, leading to_________

osteoporosis

(1)

Hematoma

(2)

Fibrocartilage

(3)

Bony Callus

(4)

Resorption of bony callus(remodeling)

Long bones form in the process called________

endochondral ossification

cartilage is replaced by the bone tissue in the______.this is the primary ossification center.  The cavity is formed in the center.

diaphysis

cartilage in the_______ is also replaced by bony tissue.  This is the secondary ossification center

epiphyses

Both primary and secondary ossification centers expand leaving a thin layer of cartilage between epiphysis and diaphysis, known as

epiphyseal plates

Bones grow in thickness due to the day-to-day remodeling: there is slightly more building than resorption taking place. This process is called

appositional growth

Cranial bones and the clavicles develop in the process called

intramembranous ossification

Mesenchymal cells differentiate into the

osteoblasts