Cartilage Histo

Question 1

Cartilage

Answer 1

Semi-rigid tissue comprised of cells and ECM
ECM has collagen and elastic fibers 
Flexible and resilient support
No nerve supply or Lymphatics
Avascular

Question 2

Chondroblasts

Answer 2

Secrete cartilage matrix

Have mitotic capabilities

Question 3

Chondrocytes

Answer 3

Cells that maintain cartilage matrix

Mature cartilage cells in lacunae

Question 4

Matrix

Answer 4

Territorial vs interterritorial
Type II collagen more prevalent
Type I collagen in fibrocartilage and outer perichondrium
Elastin fibers
Ground substance composed of proteoglycans

Question 5

Hyaline cartilage

Answer 5

Surrounded by perichondrium
“Glassy”
Contains type II collagen
Articular cartilage-no perichondrium
Trachea
Larynx
Embryonic development
Has isogenous groups
Amorphous but homogenous

Question 6

Elastic cartilage

Answer 6

Type II collagen
Made of hyaline cartilage plus elastic fibers
Surrounded by perichondrium
Epiglottis
External ear
Auditory tubes
Allow for recoil/rebound
Retains shape after deformation

Question 7

Fibrocartilage

Answer 7

No perichondrium
Hyaline cartilage and dense regular CT
Mostly type I collagen
Also contains some type II collagen
Intervertebral discs, pubic symphysis
Chondrocytes are aligned in rows and isogenous groups
Fibers oriented in the direction of functional stress
Withstands compression and shearing forces

Question 8

Territorial matrix

Answer 8

Has less collagen (type II) but more GAGs

Stains darker

Question 9

Interterritorial matrix

Answer 9

Has more collagen (type II) but less GAGs

Stains lighter

Question 10

Perichondrium

Answer 10

Surrounds hyaline and elastic cartilage
Dense irregular CT
Has vascular supply
Fibrous layer: makes type I collagen and elastin; outer transitional layer between cartilage and surrounding CT
Chondrogenic layer: secretes type II collagen; inner layer differentiates into chondroblasts

Question 11

Appositional growth

Answer 11

New cartilage grows from existing cartilage
Inner layer of perichondrium makes type I collagen
When growth is initiated, the cells turn into chondroblasts and those secrete type II collagen and ground substance

Question 12

Interstitial growth

Answer 12

Dividing of chondrocytes in lacunae
Make daughter cells
Cause increase in overall size of cartilage
Restricted because avascular

Question 13

Repair cartilage

Answer 13

Hyaline and fibrous cartilage with perichondrium
Contains type I and II collagen
Can stimulate bone growth
Facilitates the healing of bone fracture
Age dependent

Question 14

Parts of synovial joints

Answer 14

Articular capsule-synovial membrane and fibrous layer
Synovial membrane
Articular cartilage

Question 15

Articular capsule

Answer 15

Dense regular CT that gives strength
Extrinsic ligaments-outside the capsule
Intrinsic ligaments-part of the capsule

Question 16

Synovial membrane

Answer 16

Surrounds articular capsule except for articular cartilage
Makes synovial fluid
Synovium 
Absorbs shock
Regenerative properties

Question 17

Articular cartilage

Answer 17

Hyaline cartilage with no perichondrium
Reduces friction
Collagen fibers run perpendicular to the tissue surface and bend gradually
Superficial
Intermediate
Deep
Calcified zones

Question 18

Superficial zone

Answer 18

Most superficial part is devoid of cells
Flat, small chondrocytes run parallel to surface
Collagen fibers run parallel to surface

Question 19

Intermediate zone

Answer 19

Chondrocytes slightly larger and round
Occur both alone and in isogenous groups
Collagen fibers are oblique

Question 20

Deep Zone

Answer 20

Large chondrocytes form radial columns
Collagen fibers run in same direction as chondrocytes
Perpendicular to surface

Question 21

Calcified zone

Answer 21

Rests on the underlying cortex of the bone

Matrix stains slightly darker than the matrix of other layers

Question 22

Type A macrophage-like synoviocytes

Answer 22

Phagocytic
Contain lysosomes that degrade debris from friction caused by articular cartilage
25% of cells
Regulate inflammatory events

Question 23

Type B fibroblast-like synovial cells

Answer 23

Produce synovial fluid
Produce hyaluronate to combine with synovial fluid
Lubricates/nourishes the articular cartilage

Question 24

Osteoarthritis

Answer 24

Affects articular cartilage
Superficial zone during early stages
Calcified zone and to the bone during late stages