Bone Cell Types

Question 1

Osteoblasts

Answer 1

1. Matrix formation Secretes Type I collagen
2. Regulates mineralization
3. Positioned above osteoid matrix
4. Matrix usually polarized but can surround cells
5. Differentiates to become osteocyte

Question 2

Osteoclasts

Answer 2

1. Digests bone
2. Large multinucleated
3. Exhibits ruffled border and clear zone
4. Exhibits polarity with nuclei away from bone surface
5. High density of Golgi stacks, mitochondria and lysosomal vesicles

Question 3

Osteocytes

Answer 3

1. Born from osteoblasts
2. Maintains bone matrix
3. Occupies lucunae
4. Extends filopodiathrough canaliculi
5. Forms gap junctions with neighboring cells

Question 4

Bone Lining
Cells

Answer 4

1. Flat, elongated cells
2. Generally inactive
3. Cover surfaces of inactive bone
4. Thought to be precursor cells to osteoblasts