Tissue: Ossification of Cartilage at Epiphyseal Growth Plate

1. Hypertrophying Chondrocyte in Lacuna undergoing hypertrophy

2. Osteoid Tissue (non-mineralized immature bone)

Tissue: Woven Bone (unorganized collagen fibers as compared to lamellar bone)

1. Osteocyte in Lacuna

Tissue: Compact Lamellar Bone (Collagen fibers with osteocytes in lacuna organized into Osteons surrounding Haversian Canals)

1. Haversian Canal (contains blood vessels and nerve fibers)

2. Lacuna containing Osteocyte

O. Osteon

Tissue: Compact Lamellar Bone (Ground Bone Prep, Osteons with Canaliculi visible)

1. Volkmanns Canal (Horizontal canals, contain nerves and blood vessels)

2. Haversian Canal (Central Vertical Canal)

3. Canaliculi (transport nutrients between Osteocytes)

4. Osteocyte within Lacuna

Tissue: Compact Lamellar Bone (H&E stain, Collagen is eosinophilic)

1. Haversian Canal (indicates center of Osteon, difficult to see unit due to stain process)

2. Osteocyte within Lacuna

Tissue: Cancellous (Spongy) Bone

1. Marrow (fat cells with interspersed hematopoietic cells)

2. Spicule (extension of bone, eosinophilic from collagen fibers, does not usually contain Osteons in spongy bone)

3. Osteoblasts (basophilic, produce bone matrix Osteoid) at edge of Spicule.

Tissue: Cancellous (Spongy) Lamellar Bone (spicules surrounded by Osteoblasts making bone matrix, absent of Osteons)

1. Osteoblast (basophilic, at edge of spicule, creates Osteoid)

2. Osteocyte within Lacuna.

Tissue: Osteoblasts on smear

1. Osteoblast (basophilic, producing Osteoid)

1. Osteocyte

2. Canaliculi (connecting osteocytes for nutrient transfer)

1. Osteoclast (eosinophilic cytoplasm, multinucleated; absorbs bone tissue)

2. Osteoblast (basophlic cytoplasm, mononucleated)

3. Osteocyte within Lacuna

Tissue: Epiphyseal Growth Plate with endochondral ossification occurring.

1. Reserve Cartilage (very small chondrocytes)
2. Proliferative Cartilage (Chondrocytes arranged in lines)
3. Hypertrophying Cartilage Cells (Chondrocytes grow in large Lacunae)
4. Calcified (Mineralized ) Cartilage (Chondrocytes die, Last step before actual bone growth)