This document provides information on the histology of cartilage. It discusses the different types of cartilage - hyaline, elastic, and fibrocartilage. It describes their microscopic appearance, including the arrangement of cells and matrix. Key points are highlighted for each cartilage type. Locations of different cartilages in the body are also listed. The document concludes with some clinical applications and references.

1. Histology of Cartilage
Dr. Mathew Joseph MBBS, MD(AIIMS), BCC(Palliative Medicine)
Assistant Professor
Department of Anatomy
Amala Institute of Medical Sciences, Thrissur

2. Cartilage
• Modified connective tissue
• Forms skeletal basis of some parts of body
• Matrix is firm giving it the characteristic consistency
• Resists compression
• Avascular (nutrients diffuse through matrix)
• Perichondrium is rich in blood vessels

3. • Dense irregularly arranged fibrous
tissue
• Ensheaths the cartilage
• Composed of cells & matrix
• Matrix consists of fibres & ground
substance
• Houses the blood vessels that nourish
chondrocytes
• Present in most of the hyaline &
elastic cartilage
• Absent in fibrocartilage
Fibrous layer
Cellular layer
Perichondrium

4. Chondroblast
• Mesenchymal (embryologically)
• Progenitor of chondrocytes
• Lines border between perichondrium and matrix
• Produce the intercellular matrix and collagen
fibres
• Cells which become imprisoned within this
matrix become chondrocytes.

5. Chondrocyte
• Mature cartilage cell
• Reside in a space called the lacuna
• Isogenous cell group
• Basophilic
• Clear areas = Golgi and lipid droplets

6. Chondrocyte
• Chondrocytes completely fill their lacunae
• RER and euchromatic nuclei
• Synthetically active, secrete matrix
• Synthesize type II collagen, proteoglycans and
chondronectin.
Cartilage matrix
RER
N

7. Matrix
• Provides the rigidity, elasticity, & resilience
• FIBERS -Collagenous and elastic
• GROUND SUBSTANCE
• Glycosaminoglycans (chondroitin
sulfates & keratan sulfate)
• Proteoglycans
• Water
• Basophilic
• Territorial matrix
• Interterritorial matrix
• Territorial matrix surrounds lacuna (space

8. Cartilage Growth
• Interstitial
• Newly formed cartilage grows
by multiplication of cells
throughout its substance.
• Appositional
• Addition of new cartilage
over the surface of existing
cartilage.

9. Cartilage Types
• Hyaline
• Elastic
• Fibrous

10. Cartilage
Locations

11. Hyaline Cartilage
• Sites: Tracheal rings, nasal septum, larynx,
costal cartilage & articular surfaces of
joints
• Cartilage cells: Present singly or in groups
of 2 or 4 cells inside lacunae
• Cartilage Matrix: Collagen type II
• Ground substance: Homogenous, clearly
basophilic
• Functions: supportive

12. Hundreds of Eyes staring back at you

13. Identification Points - Hyaline cartilage:
1. Has encapsulated cartilage cells, forming cell nests(2-4 chondrocytes) and
ground substance appears homogenous.
2. Refractive index of collagen II is same as that of matrix, so they are not
seen separately.
3. Perichondrium covers hyaline cartilage except at articular surfaces.
4. It is avascular.
5. Trachea, Bronchial tree, Larynx

14. Elastic Cartilage
• Sites: Auricle, Ext auditory meatus,
Auditory tube, Epiglottis, Apices of
Arytenoid cartilage
• Cartilage cells: Larger, Numerous, Packed
more closely
• Cartilage Matrix: Elastic fibres, Collagen
type II
• Ground substance: Rich in elastic fibres
• Functions: Supportive with resilience
• Elastic fibers stain with orcein.

15. Identification Points - Elastic cartilage:
1. Encapsulated cartilage cells are present singly.
2. Ground substance contain elastic fibres and collagen fibers.
3. Matrix is non-homogeneous.
4. Elastic fibres are better seen with orcein stain.
5. Example Epiglottis, Cartilage of external ear, corniculate and apices of
arytenoid.

16. Fibrocartilage
• Sites: IVD, Arytenoid cartilage (except
apices), Pubic symphysis, MSJ,
Articular disc of TMJ.
• Cartilage cells: Fewer, Smaller,
scattered singly or in rows
• Cartilage Matrix: Collagen type I & II
• Ground substance: Acidophilic
• Functions: Supportive with tensile
strength
Intervertebral disc

17. Identification Points - Fibrocartilage:
1 Encapsulated chondrocytes are ovoid, surrounded by concentrically striated
matrix.
2 Chondrocytes lie in rows or layers, between rows there are bundles of collagen
fibres - Type 1.
3 Perichondrium is absent.
4 Example intervertebral disc, symphysis pubis, intra articular disc.

23. Osteoarthritis

25. Achondroplasia

26. Thank You

27. bonE
• Modified connective tissue
• Highly vascular mineralized connective tissue consisting
of cells and dense intercellular organic matrix
impregnated with inorganic salts.
• Provide support & protection to the vital organs
• Forms skeletal framework

28. Articular cartilage
Spongy bone
Marrow cavity
Compact bone
(location of
haversian systems)
Periosteum

29. Composition
• Cells:
a.Osteogenic cells
b.Osteoblasts
c.Osteocytes
d.Osteoclasts
• Fibers: collagen type I
• Ground Substance: Proteoglycans & glycoproteins

30. The matrix
of bone is a
mixture of
organic
(collagen)
and
inorganic
(calcium
phosphate)
90% of bone is
matrix, with
the remaining
10% made of
osteocytes.

31. Microscopic Anatomy of Bone
Figure 5.3

32. Lamellar arrangement
Slide
 Lamellae
 Rings around the
central canal
 Sites of lacunae
 Lacunae
 Cavities containing
bone cells
(osteocytes)
 Arranged in
concentric rings
Figure 5.3

33. Slide
 Canaliculi
Tiny canals
Radiate from the
central canal to
lacunae
Form a transport
system
Figure 5.3
Lamellar arrangement

34. compact bone
 The morphofunctional unit
of the bone is osteon, or
Haversian system.
 Lamellar pattern of compact
bone:
i. Haversian system
ii.Interstitial lamellae
iii.Circumferential lamellae

36. T.S. through compact bone
‘Haversian
Systems’

37. Dark spots are called ‘lacunae’ and
would contain osteocytes in living bone
Central canal
containing an
artery, vein,
lymph vessel
and nerves

38. What happens when excessive bending force compresses the bone…!
c
o
m
p
r
e
s
s
i
o
n
force

39. Clinical application
•Scurvy
•Rickets
•Osteomalacia
•Osteoporosis
•Osteogenesis imperfecta
•Pseudoachondroplasia

40. Save your bones

41. Take home message
• Aerobic exercises
• Low impact, weight bearing exercises
• Resistance exercises

42. References
1. diFiore’s Atlas of Histology with functional Correlations, 12th Edition.
2. Essentials of Anatomy for Dentistry Students,1st Edition.
3. Textbook of Histology, 3rd Edition.

43. MCQ
• Fibrous cartilage is present in:
1.Auricle
2.Nose
3.Tracheal rings
4.Intervertebral discs

44. Label the following
A
B
C
Don’t confuse this picture with the Liver Lobule!

45. MCQ
• Elastic cartilage is present in:
1.Apices of arytenoid cartilage
2.Epiphysis
3.Tracheal rings
4.Temporomandibular joints

46. MCQ
• Hyaline cartilage is present in:
1.Tracheal rings
2.External auditory meatus
3.Semilunar cartilages of knee joint
4.Intervertebral discs

47. MCQ
• The blood vessels and nerves go inside the compact
bone through:
1. Haversian canal
2. Volkman’s canal
3. Canaliculi
4. Interstitial lamellae