Histology - Cartilage And Bone Flashcards
Elastic cartilage
- Contains type II collagen and elastic fibers
- -> More flexible
Hyaline cartilage
- Contains type II Collagen in its matrix
- Most abundant cartilage in the body
Hyaline cartilage
Location:
- The nose
- Larynx
- Anterior ends of the ribs
- Articulating surfaces of the movable joints of the body
The matrix is composed of:
- Type II collagen
- Proteoglycans
- Glycoproteins
Which is the most abundant cartilage in the body?
The hyaline cartilage
Perichondrium
- Connective tissue covering the cartilage
- Outer fibrous layer and inner cellular layer
- Vascular, and its vessles supply nutriens to the cells of the cartilage
- Perichondria are present in:
> Hyaline cartilage
> Elastic cartilage
> NOT in fibrocartilage
Inner cellular layer (see perichondrium)
Composed of:
- Mostly chondrogenic cells
Fibrocartilage
- Contains type I collagen fibers
- Resist strong tensile forces
Outer fibrous layer (see perichondrium)
Composed of:
- Type I collagen
- Fibroblast
- Blood vessles
Pericellular caspule (p. 134)
- Small region of the matrix surrounding the lacunae
- Protect the chondrocyte from mechanical stress
Connective tissue sheath covering that overlies most cartilage and has an outer fibrous layer and inner cellular layer
Perichondrium
Chondroblast + matrix =?
Chondrocytes
Osteoblast
- Synthesize the organic components of the bone matrix components, including type I collagen, proteoglycans and glycoproteins.
- Produce RANKL, osteocalcin, osteopontine, osteonectine, bone sialoprotein, and macrophage colony-stimulating factor (M-CSF)
- Basophilic cytoplasm
- Its organelle are polarized
- Alkaline phosphatase is on the CM of osteoblast.
- Osteoid separate osteoblast and osteocyte from calcified substance
ECM of cartilage
Composed of:
- GAGS
- Proteoglycans
- Collagan
- Elastic fiber
The collagen and the elastic fibers are embedded within the matrix
Chondrification
Individual mesenchymal cells retract their processes, round up, and concregate in dense masses.
Cells of bone
- Osteoprogenitor cells
- Osteoblasts
- Osteocyte
- ## OsteoclastThe first 3 belong to the same linage.
Wheras the 4th derived from monocyte precusors
Hydration shell
- The surface ions of the crystals attract H2O and from hydration shell, which permits ion exchange with the extracellular fluid
Which cartilage posses acidophilic matrix?
Fibrocartilage
Chondronectin
- Adhesive glycoprotein in the cartilage matrix
- Has binding sites for:
> Type II collagen
> Chondroitin 4-sulfate
> Chondroitin 6-sulfate
> Hyaluronic acid
> Integrins of chondroblast and chondrocyte
–> Chondronectin thus assists these cells in maintaining their contact with the fibrous and amorphous components the matrix
Which cartilage posses basophilic matrix?
Hyaline cartilage
Bone marix
- Composed of cells lying in an ECM that has become calcified
- Calcified bone mateix is composed of:
> Fibers
> Ground substance - Fibers:
> Type I collagen - Ground substance:
> Rich in proteoglycans with chondroitin sulfate and keratan sulfate side chains
> Glycoproteins that also are present:
~ Osteonectin
~ Osteocalcin
~ Osteopontin
~ Bone sialoprotein
Periosteocytic space
Space between the plasmalemma of the osteocyte and the walls of the lacunae and canaliculi
Which cells have basophilic cytoplasm?
- Macrophages
- Osteoblast
Bone matrix
- Acidophilic
- Hydroxapatite crystal
- Hydration shell
The shaft of a long bone is called……….
Diaphysis
Articular ends of a long bone is called……..
Epiphyses
Which proteins influence the devolpment of osteoblast?
- Bone morphogenic protein (BMP) family
- Transforming growth factor-B
Small cavities within the extracellular matrix which the chondrocytes occupy is called…….
Lacunae
Periosteum
- Covers the bone on its external surface, exept for the synovial joints
- Consists of:
> Outer layer of dense fibrous connective tissue
> Inner cellular layer, containing osteoprogenitor cells and osteoblasts
Where are the gap junctions found in bone?
- Between osteoblast and osteocyte.
- Between osteocyte and osteocyte.
Bone sialoprotein
- Matrix protein that also bins to integrin of the osteoblast and osteocytes
- > this make the protein related to adherence of bone cells of bone matrix
Osteopontin
- Glycoprotein
- Binds to hydroxapatite and intergrins on osteoblast and osteocyte
Osteocalcin
- Glycoprotein
- Binds to hydroxapatite
Osteoclast-stimulating factor
Activate osteoclast to resorb bone
Osteoclast have receptors for:
- Osteoclast stimulating factor
- Colony-stimulating factor-1
- Osteoprotegrin
- Calcitonin
The inorganic constitutents of bone
- Crystals of calcium hydroxapatite, composed mostly of calcium and phosphorus
- Hydroxapatite crystal [Ca10 (PO4)6 (OH)2]
- Calcium phosphate is also prensent i an amorphous form