Histology Self Quiz—Bone
Bone is a type of _____Connective tissue______________________.
A bone can be an ____organ__________ as several types of tissues are present.
Functions
1.
2.
3.
4.
5.
Support
Mineral Storage
Protection
Movement
Blood cell production
4 Types of Cells in Bone
1.
2.
3.
4.
Osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts
Osteogenitor cells derive from mesenchymal cells. They are found in the Innermost layer of the
periosteum. Osteogenitor cells actually differentiate into osteoblasts. Osteogenitor cells aid in bone
growth and repair
Osteoblasts are immature bone cells that synthesize extracellular matrix.
The extracellular matrix consists of type 1 collagen, glycoproteins, and proteoglycans.
An osteocyte is a mature bone cell that rests in a lacuna
The process of bone formation is called osteogensis
The extracellular matrix before it is hardened is called osteoid. Osteoid is hardened when
hydroxyapetite forms a crystalline structure on collagen.
The formation of bone occurs at _____high__________ levels of _________oxygen___________.
Osteocytes are linked through tunnels called ____canicula______ by producing ____processes_____
which extend through _____canicula_______ interconnecting cells and blood supply.
An osteoclast is a multinucleate cell that causes the degradation and reabsorption and remodeling _ of
bone
The __subosteoclastic compartment ___ is the physical space in bone created by the osteoclast when it
is attached to bone
The _resorption bays__ are physical spaces in bone created by osteoclasts once it is removed from
bone.
The three zones of the osteoclast
1. Basal Zone: Top of the osteoclast, furthest from bone
2. Clear Zone: where osteoclast makes contact with the bone
3. Vesicular Zone : Contains two types of secretory vesicles. What are they? (lysosomal and
calcium)
Bone Growth
All bone growth is appositional
Endosteum is connective tissue that lines marrow cavities
Periosteum is connective tissue that lines the external surface of bone.
What are the two layers of the periosteum? 1. Inner cell layer (osteoprogenitor cells, osteoblasts) and
the Outer fibrous layer (collagen, fibroblasts, blood vessels)
What are the two types of bone?
1. Cancellous bone/ Spongy bone (more soft tissue space than of bone matrix. Soft spaces contain
blood vessels, numerous interconnecting cavities.
2. Compact bone/ dense bone: dense areas without cavities
Trabeculae- The spicules seen with spongy bone
What are the two types of bone marrow? Red(mostly hematopoetic tissue) and yellow (mostly fat)
Primary bone: the first bone to appear during embryonic development and fracture repair. Usually
temporary.
Secondary bone: Bone found primarily found in adults, which has multiple layers of calcified matrix. The
layers are called lamellae.
Compact bone is composed of osteons, the cylindrical structure within both.
Formation of an osteon
1. Osteoprogenitor cells are introduced through a new blood supply in the bone and line up
around a wall in the bone.
2. Osteoprogenitor cells differentiate into osteoblasts.
3. Osteoblasts begin making osteoid.
4. Osteoid becomes mineralized trapping mature osteocytes within the bone.
Describe blood supply in osteons: Blood supple runs through and between osteons to ensure nutrients
in constant supplt. Volkmanns canals are horizontal tunnels that carry nutrients and the central canal
does too.
Describe the different ways you can prepare a histological section of bone:
1. Decalcification: You can decalcify a section of bone with acids or a chelating agent. Then the
bone tissue is soft and can be embedded in wax and sectioned easily.
2. Ground sections: You can grind down bone until it is thin enough to look at. Cells and tissue is
destroyed but caniculi and cell lacunae are easy to see.
3. Sections of nondecalcified bon: you can embed bone is hard resin and section it with a special
knife (diamond knife)
2 types of Bone Formation
1. Intramembranous Bone Formation
2. Endochondral Bone Formation