Dr.%20Archana%20Rani

1
2.12.2014

• Dr. Archana Rani
• Associate Professor
• Department of Anatomy
• KGMU UP, Lucknow

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
PERICHONDRIUM

• 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
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.

N
RER
Cartilage matrix
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

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
TYPES OF CARTILAGE

• 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
(No Transcript)
13
ELASTIC CARTILAGE

• Sites Auricle, ext. auditory meatus, auditory
  tube, epiglottis, apices of arytenoid cartilage
• Cartilage cells larger, more 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.

14
FIBROCARTILAGE

• Sites intervertebral discs, arytenoid cartilage
  (except apices), pubic symphysis, manubriosternal
  joint, articular disc of TM joint.
• 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
15
(No Transcript)
16
Clinical application

• Osteoarthritis
• Pseudoachondroplasia

17
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

18
Articular cartilage
Spongy bone
Periosteum
Marrow cavity
Compact bone (location of haversian systems)
19
Composition

• Cells
• Osteogenic cells
• Osteoblasts
• Osteocytes
• Osteoclasts
• Fibers collagen type I
• Ground Substance Proteoglycans glycoproteins
  

20
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.
21
Microscopic Anatomy of Bone
Figure 5.3
22
Lamellar arrangement

• Lamellae
• Rings around the central canal
• Sites of lacunae
• Lacunae
• Cavities containing bone cells (osteocytes)
• Arranged in concentric rings

Figure 5.3
Slide 5.11a
23
Lamellar arrangement

• Canaliculi
• Tiny canals
• Radiate from the central canal to lacunae
• Form a transport system

Figure 5.3
Slide 5.11b
24
compact bone

• The morphofunctional unit of the bone is osteon,
  or Haversian system.
• Lamellar pattern of compact bone
• Haversian system
• Interstitial lamellae
• Circumferential lamellae

25
(No Transcript)
26
T.S. through compact bone
Haversian Systems
27
Dark spots are called lacunae and would contain
osteocytes in living bone
Central canal containing an artery, vein, lymph
vessel and nerves
28
What happens when excessive bending force
compresses the bone!
compression
force
29
Clinical application

• Scurvy
• Rickets
• Osteomalacia
• Osteoporosis
• Osteogenesis imperfecta
• Pseudoachondroplasia

30
Save your bones
31
Take home message

• Aerobic exercises
• Low impact, weight bearing exercises
• Resistance exercises

32
References

• 1. diFiores Atlas of Histology with functional
  Correlations, 12th Edition.
• 2. Essentials of Anatomy for Dentistry
  Students,1st Edition.
• 3. Textbook of Histology, 3rd Edition.

33
MCQ

• Fibrous cartilage is present in
• Auricle
• Nose
• Tracheal rings
• Intervertebral discs

34
Label the following
A
B
C
Dont confuse this picture with the Liver Lobule!
35
MCQ

• Elastic cartilage is present in
• Apices of arytenoid cartilage
• Epiphysis
• Tracheal rings
• Temporomandibular joints

36
MCQ

• Hyaline cartilage is present in
• Tracheal rings
• External auditory meatus
• Semilunar cartilages of knee joint
• Intervertebral discs

37
MCQ

• The blood vessels and nerves go inside the
  compact bone through
• 1. Haversian canal
• 2. Volkmans canal
• 3. Canaliculi
• 4. Interstitial lamellae