Cartilage

Question 1

What are hyaline cartilage derived from?

Answer 1

Mesenchymal cells

Question 2

What are the cells within hyaline cartilage?

Answer 2

Chondroblasts & Chondrocytes

Question 3

What are in the extracellular matrix of hyaline cartilage?

Answer 3

Type 2 collagen fibers

GAGs- hyalauronic acid and glycoproteins

Question 4

How does hyaline cartilage grow?

Answer 4

Appositional & interstitial growth

Question 5

How does hyaline cartilage degenerate?

Answer 5

Doesn’t really degenerate

Question 6

Describe the calcification of hyaline cartilage

Answer 6

Calcifies- bone formation & aging

Question 7

What is the function of hyaline cartilage?

Answer 7

• supportive
• cushioning
• shock absorber
• growth plate
• model for bone formations

Question 8

Describe the histology of the hyaline cartilage

Answer 8

Matrix has a “glassy” appearance because fibers and ground substance has the same refractive index

• ECM correlates to function!
• collagen
• sulfates groups

Question 9

What are the locations of hyaline cartilage?

Answer 9

• Nose (cartilaginous portion)
• Tracheal and bronchial rings
• Laryngeal cartilages
• Costal cartilages
• Articular surfaces of long bones
• Epiphyseal growth plate
• Fetal skeleton

Question 10

What is appositional growth?

Answer 10

Occurs from chondrogenic cells in the perichondrium differentiating into chondroblasts, forming a new layer of cartilage around the periphery of the existing cartilage
-This increases the width or thickness of the cartilage

Question 11

What is interstitial growth?

Answer 11

Occurs only in young cartilage from cell divisions within the cartilage
-This increases the length of the cartilage

Question 12

List in order of most influential first, what is the most influential hormones for growth?

Answer 12

• Growth hormone
• Thyroxine
• Testosterone
• Hydroxycortisone
• Estradiol

Question 13

Summarize regeneration 9f hyaline cartilage

Answer 13

Hyaline cartilage regenerates very poorly and often the perichondrium forms scar tissue

Question 14

When dies hyaline cartilage calcify?

Answer 14

In old age hyaline cartilages can get calcified

Question 15

Describe Articular cartilage

Answer 15

A type of hyaline cartilage found at Articular surfaces
-does not have perichondrium

It is in contact with Articular surface of bone on opposite side

• Remnant of original cartilage template of developing bone
• Persists throughout adult life

Question 16

What are the various regions of Articular cartilages?

Answer 16

1. Trans genital layer
2. Transitional layer
3. Radial layer
4. Calcified layer

Question 17

What are elastic cartilage derived from?

Answer 17

Mesenchymal cells

Question 18

What are the cells of elastic cartilage?

Answer 18

Chondroblasts and Chondrocytes

Question 19

What is in the Extracellular matrix of elastic cartilage?

Answer 19

• type 2 collagen fibers and elastic fibers

- GAGs and glycoproteins, multi-adhesive glycoproteins

Question 20

What kind of growth does elastic cartilage?

Answer 20

Appositional & interstitial growth

Question 21

Does elastic cartilage degenerate

Answer 21

Doesn’t readily degenerate

Question 22

Does elastic cartilage calcify?

Answer 22

Never calcify

Question 23

What is the function of elastic cartilage?

Answer 23

Support with flexibility

Question 24

What are the locations of elastic cartilage?

Answer 24

• Pinna of the ear
• external acoustic meatus
• Eustachian tube
• epiglottis

Is often found with hyaline cartilage

Question 25

Is perichondrium present in elastic cartilage?

Answer 25

Yes

Question 26

Contrast degeneration of elastic and hyaline cartilage

Answer 26

Does not degenerate as readily as hyaline cartilage

Question 27

Where is elastic cartilage found functionally?

Answer 27

• located where support with flexibility is required
• matrix is identical to that of hyaline cartilage, except it also contains a network of elastic fibers that impart to it a yellowish color on visualization of the gross specimen

Question 28

What are fibrocartilage derived from?

Answer 28

Mesenchymal cells

Question 29

What are cells of the fibrocartilage?

Answer 29

Fibroblasts transform to Chondrocytes under stress

Question 30

What is in the extracellular matrix of fibrocartilage ?

Answer 30

• produced by Chondrocytes and fibroblasts
• predominantly type 1 collagen fibers
• also contains type 2 collagen fibers
• GAGs- predominantly chondroitin and dermatan sulphates

Question 31

What kind of growth does fibrocartilage undergo?

Answer 31

Only interstitial growth (due to absence of perichondrium)

Question 32

What is the function of fubricartilage?

Answer 32

Resists deformation under stress (support and tensile strength)

Question 33

What are the locations of fibrocartilage?

Answer 33

• Intervertebral disc (annulus fibrosus)
• At the pubic symphysis
• Medial and lateral menisci
• Attachment of ligament to bone
• Intersections of some tendons and ligaments
• Articular discs

Question 34

What are the unique characteristics of fibrocartilage?

Answer 34

• Absence of perichondrium
• Matrix contains type 1 (mainly) & type 2 collagen fibers
• These fibers can be seen here with H & E and trichromatic staining
• Fibers arranged perpendicular to the direction of stress
• Can undergo calcification
• Isogenous groups are in linear fashion (longitudinal columns) due to the compression of collagen fibers
• Doesn’t occur alone, but is found in conjunction with hyaline cartilage and other fibrous tissue