Meghan Barboza, PhD
Online Course
Specialized forms of Connective
Tissue
Cartilage
Bone
Blood
Main Functions of Cartilage
 Resists compression
and tension
 Support soft tissue
 Provide sliding areas
for joints
 Foundation for bone
development
Principal Characteristics
 Form cell nests (isogenic
cell groups)
 Consist of chondrocytes
 Rounded, independent
cells
 Avascular
 Noninnervated
Perichondrium
 Layer of tissue
surrounding
cartilage
cartilage
Perichondrium
 Two layers of dense
irregular CT:
 Outer Layer contains
perichondrial fibroblasts
 Inner layer is
chondrogenic

producing the
chondroblasts/
chondrocytes
http://audilab.bmed.mcgill.ca/HA/html/bc_2_E.html
Perichondrium
Chondroblast/Chondrocyte
 Both originate
from
mesenchyme of
the inner layer of
perichondrium
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Secretions of Chondrocytes
 Collagen type 2
 Collagen type 1
 Fibrocartilage only
 Proteoglycans
 Glycoproteins
 Fluid
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Cartilage’s ECM
 Interterritorial matrix
Cartilage’s ECM
 Interterritorial matrix
 Territorial matrix
Cartilage’s ECM
 Interterritorial matrix
 Territorial matrix
 Pericellular capsule
Cartilage
 Lacunae
 The space that
contains the
chondrocytes.
 Can contain
multiple cells.
3 Types of Cartilage
 Hyaline
 Elastic
 Fibrous or fibrocartilage
Differentiation based on prevailing type of fiber
Hyaline Cartilage
 Collagen type II made by
chondroblast/chondrocytes and
containing chondrocytes
 Most common: tracheal rings, nose, joint
surfaces, and site of long & short bone
development
Elastic Cartilage
 Epiglottis, external
ear, Eustachian tube
 Similar isogenic
nests
 Collagen type II and
elastic fibers
Perichondrium
Fibrocartilage
 Intervertebral
discs (inner-most),
and selected
ligamentous and
tendinous
attachments to
other bones
vertebra
nucleus
pulposus
Fibrocartilage
 Linear isogenic
nests
 Collagen type I
 No perichondrium
Chondrogenesis: Appositional
Growth
Appositional
To grow
outwards
Requires a
perichondrium
Chondrogenesis:
Interstitial Growth
 Interstitial
 To grow into already
occupied space
Endochondral Bone Formation
 A combination of
appositional and interstitial
growth of cartilage (blue).
 Followed by replacement of
that cartilage with bone
(yellow).
Check your understanding
 Cauliflower ear, pictured to the right,
occurs when fluid accumulates under
the perichondrium. What has
happened to the cartilage? Will this
cause pain throughout a person’s life?
 What is the ‘soft spot’ on a
newborn’s head?
 What causes the condition to
the right in infants?
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