Dr.%20Archana%20Rani - PowerPoint PPT Presentation

Title: Dr.%20Archana%20Rani


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2.12.2014

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

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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

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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
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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.

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CHONDROCYTE

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

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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
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MATRIX

• Provides the rigidity, elasticity, resilience
• FIBERS
• Collagenous and elastic
• GROUND SUBSTANCE
• Glycosaminoglycans (chondroitin sulfates
  keratan sulfate)
• Proteoglycans
• Water
• Basophilic
• Territorial matrix
• Interterritorial matrix

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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.

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TYPES OF CARTILAGE

• HYALINE
• ELASTIC
• FIBROUS

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CARTILAGE LOCATIONS
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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

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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.

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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
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Clinical application

• Osteoarthritis
• Pseudoachondroplasia

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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

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

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

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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.
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Microscopic Anatomy of Bone
Figure 5.3
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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
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Lamellar arrangement

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

Figure 5.3
Slide 5.11b
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compact bone

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

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T.S. through compact bone
Haversian Systems
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Dark spots are called lacunae and would contain
osteocytes in living bone
Central canal containing an artery, vein, lymph
vessel and nerves
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What happens when excessive bending force
compresses the bone!
compression
force
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Clinical application

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

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Save your bones
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Take home message

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

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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.

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MCQ

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

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

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

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MCQ

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

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MCQ

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