1. Department of Human Morphology and Developmental Biology, 2013
CARTILAGE. BONE TISSUE
Judith Molnár
Department of Human Morphology and Developmental Biology, 2013

2. Cartilage Special dense connective tissue Types Cells Matrix
fibers
ground substance, intercellular matrix (ICM)
Types
Hyaline cartilage
Elastic cartilage
Fibrocartilage

4. Hyaline cartilage Occurrence Macroscopic appearance:
ribs, articulating surfaces, respiratory organ,
fetal skeleton
Macroscopic appearance:
transparent, blueish white, (matrix )
Microscopical appearance:
cells are embedded into a well stained matrix, surrounded by perichondrium
Perichondrium (exception: articulating surface)
outer: fibrous connective tissue, type II collagen
Inner : cellular (chondroblasts)

5. Hyaline cartilage Cells Cell groups
chondrocytes, large spherical cells
under the perichondrium and on the articulating surfaces elongated
basophilic cytoplasm, lipid droplets, glycogen, shrinkage due to fixatives
Cell groups
single cell under the perichondrium and on the articulating surface, matured cartilage: isogenic groups (2, 4, 8)

6. Hyaline cartilage matrix
Homogenous basophilic staining
Cells in lacunae
Gel like matrix impregnate the collagen fiber network
Fibrils: same refractive index as matrix, polarizing light microscope
Chemical composition
high water content (70%)
proteoglycans (chondroitin sulphate, keratin sulphate)
hyluronic acid
type II. collagen

7. Hyalin cartilage matrix
Territorial matrix: more glycosamino-glycans cause deeper basophilic staining
basophilic capsule
basophilic territorial matrix
acidophilic territorial matrix
Chondron: cells+ territorial matrix
Interterritorial matrix
basophilic/acidophilic staining

8. Hyaline cartilage metabolism
Nutrition
no blood vessels, anaerobic, low metabolic activity, diffusion, no nerves and lymph vessels
Development, growth
primordial cartilage –chondrocytes – matrix
interstitial growth (cells, matrix)
appositionalis growth (from the perichondrium )
Regression
ossificatio
degeneration

19. Elastic cartilage Occurrence Macroscopical appearance
External ear, epiglottis
Macroscopical appearance
yellowish, less transparent
Microscopical appearance
chondrons: smaller than in the hyaline cartilage, capsule similar, elastic fibers in the matrix
Growth
Similar to the hyaline cartilage

25. Fibrocartilage Occurrence Macroscopical appearance
intervertebral disks, meniscs, articulating surface, grooves for tendons on bone
Macroscopical appearance
tough, fibrous tissue, no perichondrium
Microscopical appearance
single or groups of cells arranged in rows in the chondrons, type I collagen in the matrix
Regeneration
no repair, matured cells do not divide

31. Bone The most differentiated supporting tissue Primary (woven) bone
cells (osteocytes)
intercellular material
fibers
ground substance
organic (matrix)
anorganic (Ca, Mg salts)
Primary (woven) bone
Secondary (laminar) bone

32. General characteristics of bone
Macroscopical features
compact and spongy bones
periosteum, endosteum
cavities -medulla
Chemical composition
anorganic components: hardness and rigidity
organic components: toughness and elasticity
calcination, decalcination
Classification of bones
ossa longa, breve, plana, irregularia

33. Microscopical structure of bone
Cells
progenitor cells: osteoblast – osteocyta
lacuna, canaliculi ossei
osteoclast
multinucleated giant cells (Howship’s lacuna)
Intercellular material
fibers: type I. collagen form laminae
diameter: nm, periodicity 67 nm
matrix
proteoglycan: GAG, chondroitin sulphate, keratinsulphate
hyaluronic acid
bone specific proteins
osteocalcin, osteopontin, bone sialoprotein
anorganic components (67%), arranged along the fibers
Ca,- Mg phosphate, carbonate

34. Microscopical structure of bone
Laminae
matrix arranged in laminae (3-7μm), parallel layout, concentric tubes, parallel to the long axis of the bone (alternating angles in the adjacent layers)
laminae speciales, intercalares, fundamentales externa and interna
Lacunae
in between the laminae osteocytes, canaliculi ossei perforating the laminae
Osteon
laminae speciales around the Haversian canals (0.1 mm)
Volkmann’s canals connecting them to each other and the surface
blood vessels, lymph vessels, nerves

35. Microscopical structure of bone
Periosteum
str. fibrosum – dense connective tissue, vessels, nerves, Sharpey’ fibers
str. osteoblasticum – developing bone, resting bone
Endosteum
in adults: reticular connective tissue, latens capacity for bone production and desorption
Spongy bone
trabeculae, laminae, tubes – basic structure : laminae
Compact bone
gradual transition between compact and spongy bone

36. Metabolic activity Blood supply Regenerative ability
from the periosteum, Volkmann’s and Hawersian canals
diffusion through the continuous spaces
osteocytes ~ 0.1 mm from the capillaries (~ 0.2 mm at maximum)
Regenerative ability
Continuous remodeling
Appearance in sections
cross section, longitudinal section

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