Cartilage

Question 1

What is cartilage?

Answer 1

Semi-rigid tissue comprised of cells and ECM

Question 2

What are the components of ECM?

Answer 2

Collagen and elastic fibers

Question 3

What are the components of cartilage?

Answer 3

Cells - Chondroblasts, chondrocytes

Matrix- collagen fibers (type 1 or 2) and ground substance

Question 4

What are chondroblasts?

Answer 4

Immature cells that secrete components of cartilage ECM (appositional growth)

Question 5

What are chondrocytes?

Answer 5

Mature cartilage cells in lacunae that secrete ECM and nourish cartilage. Derived from chondroblasts. Interstitial growth

Question 6

What are the three types of cartilage?

Answer 6

Hyaline, elastic and fibrocartilage

Question 7

What type of collagen does hyaline cartilage contain?

Answer 7

Type II collagen

Question 8

Where is hyaline cartilage found?

Answer 8

Articular cartilage, larynx, trachea, ribs, embryonic development

Question 9

What type of collagen does Elastic cartilage have?

Answer 9

Type II collagen

Question 10

Where is elastic cartilage located?

Answer 10

External ear, epiglottis, auditory tube

Question 11

What type of collagen does fibrocartilage contain?

Answer 11

Type I collagen

Question 12

Where is fibrocartilage located?

Answer 12

Intervertebral discs, pubic symphysis, TMJ

Question 13

what is an isogenous group?

Answer 13

Two or three chondrocytes grouped together

Question 14

What is the territorial matrix? Where is the inter territorial matrix?

Answer 14

Territorial - A matrix that directly surrounds isogenous group.

Interterritorial- surrounds the territorial matrix

Question 15

What is the difference (in staining and characteristics) between territorial and interterritorial matrix?

Answer 15

Territorial is moderately staining, while territorial is less intensely stained. Territorial has decreased collagen while interterritorial has more collagen II and fewer proteoglycans

Question 16

What is perichondrium?

Answer 16

It is dense irregular CT that surrounds hyaline and elastic cartilage. It’s a source of new cartilage cells

Question 17

What is the fibrous layer of perichondrium?

Answer 17

The outer layer that produces type I collagen and elastin

Question 18

What is the chondrogenic layer of perichondrium?

Answer 18

The inner layer that differentiates into chondroblasts. Secretes type II collagen

Question 19

What is elastic cartilage?

Answer 19

Components of hyaline cartilage plus elastic fibers within the matrix; surrounded by perichondrium

Question 20

What is fibrocartilage?

Answer 20

A combination of hyaline cartilage and dense regular CT (has type 1and type 2 collagen and a lack of perichondrium)

Question 21

What is appositional growth

Answer 21

Chondrogenesis of new cartilage on the surface of existing cartilage; chondrogenesis cells located within inner layer of perichondrium

Question 22

What is interstitial growth?

Answer 22

Chondrogenesis that takes place within a cartilage mass; chondrocytes divide within lacunae, creating new isogenous groups

Question 23

Why is cartilage repair capacity limited?

Answer 23

Due to its avascular nature

Question 24

What is repair cartilage?

Answer 24

An ECM matrix composition intermediate of hyaline and fibrous cartilage. It contains type 1 and 2. Facilitates healing of a bone fracture

Question 25

Describe the components of an articular capsule

Answer 25

It has an outer fibrous layer made of dense regular CT and extrinsic (separate from capsule) and intrinsic (part of fibrous capsule) ligaments

Question 26

Describe articular cartilage

Answer 26

It is hyaline cartilage, it reduces friction, its avascular and lacks nerve supply and it is nourished by synovial fluid

Question 27

Describe synovial membrane

Answer 27

Synovium; lines joint cavities (except articular cartilage), lubricates articular cartilage, has a vascular CT membrane, produces synovial fluid, has regenerative properties and absorbs shock

Question 28

What are the three components of synovial joints

Answer 28

Synovial membrane, articular capsule and articular cartilage

Question 29

What are synoviocytes?

Answer 29

Cells in the joints of synovium

Question 30

What are type A macrophage like synovial cells?

Answer 30

They are phagocytosis cells what contain lysosomes to clear articular cavities of debris formed by friction of articular cartilages. Make up 25% of the cells lining synovium. Regulate Inflammatory events

Question 31

What are type B fibroblast like synovial cells?

Answer 31

They are cells that produce synovial fluid (plasma filtrate) and produce hyaluronate that combines with synovial fluid. They lubricate and nourish the articular cartilage.

Question 32

What are the four zones of articular cartilage

Answer 32

Superficial (tangential) Intermediate (transitional) Deep (radial) Calcified

Question 33

What are three characteristics of the superficial zone of articular cartilage?

Answer 33

Chondrocytes are small and flattened parallel to the surface Most superficial region is devoid of cells Collagen fibers run parallel to surface

Question 34

What are three characteristics of the intermediate zone of articular cartilage?

Answer 34

Chondrocytes are slightly larger and round Occur both alone and in isogenous groups Collagen fibers take an oblique course through the matrix

Question 35

What are three characteristics of the deep zone of articular cartilage?

Answer 35

Large chondrocytes form radial columns Stacks are oriented perpendicular to the articulating surface Collagen fibers follow orientation of chondrocytes columns

Question 36

What are two characteristics of the calcified zone of articular cartilage?

Answer 36

Rests on the underlying cortex of the bone Matrix of the calcified cartilage layer stains slightly dark than the matrix of other layers

Question 37

What is osteoarthritis?

Answer 37

A degenerative joint disease; characterizes by chronic joint pain and various degrees of joint deformity and destruction of articular cartilage

Question 38

What happens in the early stages of osteoarthritis?

Answer 38

Superficial layer of articular cartilage is disrupted

Question 39

What happens in the late stages of osteoarthritis?

Answer 39

Destruction of the cartilage extends to the bone, where the exposed subchondral bone becomes new articular surface (progressive reduction of mobility and increased pain)