SM 219a - Bone Histology Flashcards
What is the structural unit of compact bone?
Haversian System (aka Osteon)
What is the source of new material for the growth in length of a bone?
Dividing cartilage cells
Which part of the bone is indicated by #6?
Cortex
Made up of lamellar (compact) bone
What structure is #1 pointing to?
Osteoid
(An unmineralized, organic portion of the matrix)
What kind of bone is predominant in this image?
Lamellar bone
(aka Mature Bone or Compact Bone)
The bone is organized into lamellae (layers)
Which cells in the bone are multinucleated giant cells?
Osteoclasts
They reabsorb bone
Which part of the bone is indicated by #7?
Medullary Cavity
Made up of trabecular (spongey) bone
What structure is #2 pointing to?
Woven Bone (aka Immature Bone)
Mineralized, but not organized into lamellae
What substance initiates mineralization of bone?
Small vescicles exocytosed by ostoblasts filled with alkaline posphatase and pyrophsophate
What is osteoid?
Organic matrix that is not yet mineralized (but will be)
Osteoid -> Mineralized to woven bone -> Matures into lamellar bone
Which part of the bone is indicated by #4?
Epiphysis
(also #5)
What structures run through the “canal” of the Haversian System?
Blood vessels and nerve fibers
https://peir-vm.path.uab.edu/wsi.php?slide=UAB-Histology-00009
Osteoid in a malignant tumor indicates what kind of tumor?
Osteosarcoma
(patho-pneumonic)
Which structure is indicated by #3?
Osteocyte Lacunae
https://peir-vm.path.uab.edu/wsi.php?slide=UAB-Histology-00009
Which structure is indicated by #2?
Canal
Contains blood vessels and nerve fibers
https://peir-vm.path.uab.edu/wsi.php?slide=UAB-Histology-00009
What are the cellular components of bone?
Osteoblasts - Synthesize bone
Osteocytes - Mature osteoblasts
Osteoclasts - Resorb bone
Describe what is happening in Zone 3
Cartilage cells are proliferating
This is the Zone of Proliferation
https://peir-vm.path.uab.edu/wsi.php?slide=UAB-Histology-00068
Which ossification process does this statement describe?
“New bone develops directly from a capsule of undifferentiated connective tissue”
Intramembranous ossification
Occurs in the flat bones of the face, cranial bones, and clavicles
In which zone will you find non-active cartilage?
4 - Reserve Cartilage
https://peir-vm.path.uab.edu/wsi.php?slide=UAB-Histology-00068