Basics of the cartilage histology for medical school students

1. Cartilage Histology
By
Dr: Mohamed Attia
Azhar Medical School 2020

2. • Introduction
A) Cartilage is a type of C.T with rubbery matrix.
Formed of:
• 1) Cells.
• 2) Matrix: ground substances and fibers.
• 3) Perichondrium.
C) The matrix is; a vascular, a neural, a lymphatic , basophilic
and metachromatic.
D) Cells lie in lacunae (matrix cavity).
E) Nutrition reach to the cells by diffusion from blood capillaries
of perichondrium.
Prof; Sherif Saleh ,
Dr; M.Attia
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3. There three types of cartilage:
1) Hyaline (glassy).
2) Elastic.
3) Fibrocartilage.
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6. • Perichondrium
• A capsule like sheath of dense C.T that surrounds
cartilage.
• A) Outer fibrous layer:
• Formed of collagen bundles (collagen type II),
fibroblasts and many blood vessels.
• B) Inner cellular (chondrogenic) layer:
• Formed of chondrogenic cells and chondroblasts
which changed into mature chondrocytes.
Prof; Sherif Saleh ,
Dr; M.Attia
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7. Functions:
1) Supply cartilage with nutrition from its blood vessels
by diffusion in the matrix.
2) Appositional growth.
3) Repair of cartilage.
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Dr; M.Attia
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9. • Matrix
• It is formed of:
• 1) Collagen (type II) fibrils.
• * Too thin to be seen by L.M.
• * Has same R.I as the matrix.
• 2) Water 80%.
• 3) Ground material:
• a) Glycoprotein (chondronectin); which have an
adhesive function.
• b) Hyalouronic acid.
• c) Proteoglycans (aggrecan); each 200 aggrecan bind
to hyalouronic acid.
Prof; Sherif Saleh ,
Dr; M.Attia
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11. Territorial (capsular) Interterrtorial
Located around
chondrocytes beside
capsule.
Surround the matrix
High GAGs Less
High basophilia Less
Less collagen High collagen
PAS +++ (intense) +
Types of matrix
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14. • Functions of chondrocytes
• 1) Secretion of collagen type II fibrils.
• 2) Secretion of GAGs & proteoglycans.
• 3) Responsible for interstitial growth.
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Dr; M.Attia
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15. Sites of hyaline cartilage
1) Costal cartilage.
2) Respiratory passage; vestibule of the nose
trachea and bronchi.
3) Skeleton of the fetus.
4) Articular cartilage.
5) Epiphyseal plate.
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18. B) Elastic cartilage
• A special type of cartilage similar to hyaline
cartilage with abundant elastic fibers.
• Appear yellow in fresh state.
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19. Sites:
It is present in:
The ear (ear pinna, external auditory meatus and Eustachian tube).
Larynx (epiglottis, cuneiform and corniculate cartilages).
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21. • Structure:
• I) Perichondrium.
• II) Matrix that contains:
Cells (chondrocytes).
• Fibers (very rich in elastic fibers) with few collagen
type II fibers.
• Small amount of intercellular matrix and ground
substances and tissue fluids.
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23. Function:
Allows elastic recoil of some structures when
moved, changing the shape of the structure
without deformity.
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27. • C) White fibro cartilage
• A special type of firm, opaque cartilage.
• It is strong to resist stretching.
• Sites:
Intervertebral disks.
Symphysis pubis.
Labrum of the glenoid cavity of shoulder.
Labrum of the cetabulum of hip joint.
Semilunar cartilage ( meniscus) of knee joint.
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31. • Characters:
• White and opaque in color, no perichondrium.
• Very rich in type I collagen so its matrix appears
acidophilic with H & E.
• Cartilage cells arranged in rows (single or in
groups) separated by acidophilic collagen bundles
(easily seen by LM).
• Very strong to resist stretching (very little ground
substances).
• Dense fibrous C.T rich in blood capillaries for its
nourishment, the capillaries pass with the collagen
bundles, so no perichondrium.
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32. White fibro cartilage
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35. Thank you
All the best
Prof; Sherif Saleh ,
Dr; M.Attia
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