Cartilage

Question 1

Chondrocytes

Answer 1

Mature cartilage cells in lacunae

- Maintain matrix

Question 2

Chondroblasts

Answer 2

Cells that secrete cartilage matrix

Mitotic capabilities

Question 3

What is the ground substance of cartilage composed up?

What are the 4 types?

Answer 3

Proteoglycans

• Hyaluronic acid
• Chondroitin sulfate
• Keratin sulfate
• Aggrecan

Question 4

Where is Type I collagen present in cartilage matrix?

Answer 4

• Fibrocartilage, outer perichondrium

Question 5

What are the three types of cartilage? What type of fiber does each contain?

Answer 5

1. Hyaline: Type II Collagen
2. Elastic: Type II Collagen
3. Fibrocartilage: Type I Collagen

Question 6

Where is Hyalin cartilage found?

Answer 6

Articular cartilage
larynx
trachea
ribs
embryonic development

Question 7

Where is elastic cartilage found?

Answer 7

External ear
Epiglottis
Auditory Tube

Question 8

Where is Fibrocartilage found?

Answer 8

Intervertebral discs
Pubic Symphysis
TMJ

Question 9

What kind of cartilage lacks a perichondrium?

Answer 9

• Fibrocartilage

- Articular cartilages

Question 10

What is the territorial matrix composed of?

Answer 10

Randomly arranged Type II collagen

• High GAGs
• Decreased collagen

(Moderate staining)

Question 11

What is interterritorial matrix composed of?

Answer 11

• Surrounds territorial matrix
• Mostly collagen II, fewer proteoglycans

(Less intensely staining)

Question 12

Characteristics of the perichondrium?

Answer 12

Dense, irregular CT

Contains vascular supply

Hyalin + elastic cartilage only

Question 13

What is the source of new cartilage cells?

Answer 13

Perichondrium

Question 14

What is the fibrous layer of the Perichondrium?

Answer 14

Outer layer that produces Type I collagen and elastin

Transitional zone

Question 15

What is the chondrogenic later of the perichondrium?

Answer 15

Inner layer that differentiates into chondroblasts

- Secretes type II collagen

Question 16

What is elastic cartilage composed of?

What is its function?

Answer 16

Hyalin cartilage + elastic fibers within the matrix

Recoil/ Rebound, retains shape after deformation

Surrounded by perichondrium

Question 17

What is fibrocartilage composed of?

Answer 17

Hyaline cartilage + dense regular CT

• Type I + Type II collagen
• Less cartilage matrix
• Lacks perichondrium

Question 18

What is the function of fibrocartilage?

Answer 18

Withstand compression and shearing forces

Question 19

What are the steps of appositional growth of cartilage?

Answer 19

Forms new cartilage on the surface of existing cartilage

1. Growth is initiated
2. Cells —> chondroblasts
3. Secrete type II collagen and ground substance

Question 20

What are the steps of interstitial growth of cartilage?

Answer 20

Takes place within a cartilage mass

• Chondrocytes divide within lacunae, create new isogenous groups
• Secrete more matrix
• Limited by avascular nature

Question 21

When is repair cartilage formed?

Answer 21

When perichondrium is involved

• stimulates bone growth
• facilitates healing bone fracture
• repair is age dependent

Question 22

What type of cartilage is found in articular cartilage?

What are the functions of articular cartilage?

Answer 22

1. Hyaline cartilage

2. Reduce friction, avascular, nourished by synovial fluid

Question 23

What type of tissue makes up the articular capsule?

Answer 23

Dense regular CT

• Responsible for strengthening the joint

Question 24

What is the difference between extrinsic and intrinsic ligaments? (Articular capsule)

Answer 24

Extrinsic = separate from capsule

Intrinsic = part of the fibrous capsule

Question 25

What is the function of Type A Macrophage-like synovial cells? What percent of the synovium lining are these type of cells?

Answer 25

Phagocytosis (contains lysosomes) 25% of cells lining the synovium

Question 26

Type B Fibroblast-like synovial cells

Answer 26

- produce synovial fluid - produce hyaluronate that combines with synovial fluid Lubricates and nourishes articular cartilage

Question 27

What are the different layers of articular cartilage? What are the characteristics of cells in each of these layers?

Answer 27

1. Superficial: small, flattened chondrocytes parallel to the surface 2. Intermediate (transitional): slightly rounder, larger chondrocytes in isogenous groups or alone 3. Deep (radial): Large condrocytes in radial columns, perpendicular to the articulated surface 4. Calcified: on the underlying cortex of bone

Question 28

What are the clinical characteristics of Osteoarthritis?

Answer 28

Chronic joint pain, various degrees of joint deformity + destruction of articular cartilage

Question 29

What happens in the early stages of osteoarthritis?

Answer 29

Superficial layer of articular cartilage is disrupted

Question 30

What happens in the late stages of osteoarthritis?

Answer 30

Destruction of the cartilage extends to the bone, exposed subchondral bone becomes new articular surface