Lab 2: Development of the Crainoskeleton: Exam 2

Question 1

What is an Osteoprogenitor cell?

Answer 1

Stem cell capable of mitosis

Question 2

What is an Osteoblast?

Answer 2

Located on periphery; responsible for synthesis of bone matrix

Question 3

What is an Osteoclast?

Answer 3

Multinucleated cell; involved in remodeling and resorption through phagocytosis maintains blood calcium homeostasis in response to hormones

Question 4

What is the Periosteum?

Answer 4

Name of CT covering bone surfaces;

Covers external surface: DRCT containing fibroblasts and inner layer of osteoprogenitor cells

Question 5

What is the Endosteum?

Answer 5

Name of CT covering bone surface;

Covers internal surface of single layer of osteoprogenitor cells and a small amount of CT

Question 6

What are key features of Bone extracellular matrix (Osteoid)?

Answer 6

Mineralized matrix containing higher amounts of fibers than ground substance

Question 7

Describe the organic components of bones:

Answer 7

• (30-35%)
• Fibrous proteins– Type I collage
• Non-fibrous proteins– GAGS and proteoglycans (chondroitin sulfate, keratin sulfate)
• Glycoproteins (Osteonectin; Osteocalcin) (10%)

Question 8

Describe the inorganic components of bones:

Answer 8

(65-70%)

- Hydroxyapatite (Calcium and phosphate)