•Specialized connective tissue
•Rigid, Elastic, Resilient RESISTS COMPRESSION
•AVASCULAR –
nutrients diffuse through matrix
Hundreds of Eyes Staring Back at
YOU!
PERICHONDRIUM
• Dense irregularly
arranged connective
tissue (type I collagen)
• Ensheaths the cartilage
• Houses the blood
vessels that nourish
chondrocytes
CHONDROBLAST
• Progenitor of
chondrocytes
• Lines border between
perichondrium and
matrix
• Secretes type II collagen
and other ECM
components
• Chondroblasts build
CHONDROCYTE
• Mature cartilage cell
• Reside in a space
called the lacuna
• Clear areas = Golgi
and lipid droplets
• Chondrocytes
completely fill their
lacunae
• RER and euchromatic
nuclei
• Synthetically active,
secrete matrix
N
RER
Cartilage matrix
MATRIX
• Provides the rigidity,
elasticity, & resilience
• FIBERS
– Collagenous and elastic
• GROUND SUBSTANCE
– Glycosaminoglycans
(chondroitin sulfates, keratin
sulfate, hyaluronic acid)
– Proteoglycans: GAGs + core
protein
– Water
• Basophilic
• Territorial matrix - high [ ] of
sulfated proteoglycans
CARTILAGE GROWTH
• Appositional
– Increasing in WIDTH;
chondroblasts deposit
matrix on surface of
pre-existing cartilage
• Interstitial
– Increasing in
LENGTH;
chondrocytes divide
and secrete matrix
from w/in lacunae
TYPES OF CARTILAGE
• HYALINE
• ELASTIC
• FIBROUS
HYALINE CARTILAGE
• FUNCTION
– Support tissue and organs
– Model for bone
development
• MATRIX
– Type II collagen (thin
fibrils)
– Chondroitin sulfate, keratin
sulfate, hyaluronic acid
– Water
• LOCATION
– Tracheal rings, nasal
septum, larynx, articular
surfaces of joints
ELASTIC CARTILAGE
• FUNCTION
– Support with flexibility
• MATRIX
– Normal components of hyaline
matrix plus ELASTIC fibers
• LOCATION
– External ear, external auditory
canal, epiglottis
• STAINS
– Elastic fibers stain BLACK
with Weigert stain
perichondrium
FIBROCARTILAGE
Orcein van Giesen Elastic stain - fibrocartilage - reddish brown
hyaline cartilage - yellow
FIBROCARTILAGE
• FUNCTION
– Support with great
tensile strength
• MATRIX
– Type I collagen Oriented parallel to
stress plane
• LOCATION
– Intervertebral disks,
pubic symphysis
FIBROCARTILAGE
• Chondrocytes align
between collagen fibers
• Collagen fibers lie
parallel to lines of stress
How many types of cartilage do
you see?
SYNOVIAL (DIARTHRODIAL)
JOINTS
JOINT DEFINITIONS
• SYNOVIAL CAVITY
– Fluid filled space b/t 2 bones
• SYNOVIAL FLUID
– Water and GAGs; provides
nutrients for cartilage
• SYNOVIAL MEMBRANE
– Continuous with the
perichondrium
SYNOVIAL “MEMBRANE”
Not a true membrane Why?
• Specialized secretory CT
• Loose (areolar) CT
• Formed by layers of
collagen and fibroblasts
• Highly vascular
• No perichondrium
• Joint capsule
composed of DIACT
• Why does the cartilage
at the joint stain so
acidophilic (i.e. pink)?
Question 1
A
Panel C is a low magnification micrograph of the
tissue shown in Panel B.
Provide the letter or letters (A and/or B) (or none)
of the panel to which the following apply.
normally calcified
vascularized
collagen type II
cells capable of division
matrix contains proteoglycans
lacunae present
C
B
C
A
Questions 2 and 3:
2. The three tissues shown have all of the following properties in
common EXCEPT:
a.
b.
c.
d.
B
They contain capillaries.
They contain proteoglycans.
They can increase in size by interstitial growth.
They can increase in size by appositional growth.
3. Which tissue is the most highly specialized to resist
compression?
a. A
b. B
c. C
Question 4
4. What cartilage
nourishing
tissue is
missing at the
interface
shown?
a. Synovial fluid
b. Perichondrium
c. Synovial
membrane
d. Chondroblasts