Cartilage

Question 1

All cartilage posses perichondrium except for: (3 things)

Answer 1

1. epiphyseal growth plate
2. fibro-cartilage
3. articular cartilage

Question 2

Which type of cartilage growth occurs by differentiation of perichondrial fibroblasts into chondrocytes and chondroblasts?

Answer 2

Appositional Growth

Question 3

Which type of cartilage growth occurs by mitosis of existing chondroblasts and chondrocytes and is restricted only to those sites without a perichondrium?

Answer 3

Interstitial growth

Question 4

What are the four characteristics of the perichondrium?

Answer 4

1. All cartilage posses perichondrium (except epiphyseal growth plate, fibro and articular cartilage)
2. Essential for appositional growth
3. Provides nutrients
4. Sox transcription factors induce differentiation into chrondroblasts

Question 5

Interstitial Growth occurs in cartilage that lack a ?

Answer 5

perichondrium

Question 6

Interstitial growth occurs as a functional growth hormone from the (Somatotropin):

Answer 6

pituitary that stimulates somatomedin C from liver that stimulates mitosis of chondroblasts and chondrocytes

Question 7

Achondroplasia?

Answer 7

1. no cartilage growth

2. typically presents as dwarfism

Question 8

Hyaline cartilage contains no blood vessels referring to?

Answer 8

avascular

Question 9

clusters of cell in isogenous cartilage can be formed by?

Answer 9

interstitial growth

Question 10

A chunk of the cartilage that breaks can cause pain because there is free floating cartilage that is getting caught in your articular joint (damage of cartilage covering articulating surfaces), which refers to?

Answer 10

Osteoarthritis

Question 11

Swelling of the membranes which puts pressure on the joints refers to?

Answer 11

rheumatoid arthritis

Question 12

Characteristics of Hyaline cartilage:

Answer 12

1. Type II collagen
2. basophilic matrix
3. chondrocytes usually arranged in groups
   (perichondrium present in most places; except for articular cartilages and epiphses)

Question 13

Characteristics of Elastic Cartilage:

Answer 13

1. Type II collagen
2. elastic fibers
   (perichondrium present)

Question 14

Characteristics of Fibrocartilage:

Answer 14

1. Type II collagen
2. acidophilic matrix
3. chondrocytes arranged in parallel rows between bundles of collagen
4. always associated with dense regular collagenous connective tissue or hyaline cartilage
   (perichondrium absent)

Question 15

Where is Hyaline cartilage located?

Answer 15

Articular ends of long bones, nose, larynx, trachea, bronchi, ventral ends of ribs

Question 16

Where is elastic cartilage located?

Answer 16

Pinna of ear, walls of auditory canal, auditory tube, epiglottis, cuneiform cartilage of larynx

Question 17

Where is fibrocartilage located?

Answer 17

Intervertebral disks, articular disks, pubic symphysis, insertion of some tendons

Question 18

Characteristics of cartilage (4)

Answer 18

1. Amorphous ECM predominates over fibrous ECM
2. Rich in Proteoglycans
3. Functions in Support and Flexibility for sliding of joints, as a shock absorber and growth of long bones
4. Presence declines from fetus to adult (follows evolution of the vertebrates)

Question 19

Components of cartilage: cellular

Answer 19

a) Perichondrial fibroblasts
b) Chondroblasts
c) Chondrocytes
d) Chondroclasts (i.e. osteoblasts)

Question 20

Components of cartilage: Extracellular Matrix (40%)

Answer 20

1. Amorphous matrix predominates – mostly glycosaminoglycans, proteoglycans (aggrecan, syndecan, fibroglycan) and glycoproteins (chondronectin, chondrocalcin)
2. Fibrous component less prominent with mostly Type II collagen (hyaline cartilage), Type I collagen (fibrocartilage) and elastic fibers (elastic cartilage)

Question 21

Characteristics of chondroclasts (4)

Answer 21

1. associated with cartilage resorption
2. similar to osteoclasts in morphology and function
3. In endochondral ossification, their function is to remove calcified cartilage
4. appear to enter cartilage with vasculature (may derive from monoctyes)

Question 22

Characteristics of Non-Vascularity of Cartilage (3)

Answer 22

1. No blood supply - channels form fracture planes
2. Diffusion is rate limiting to thickness of cartilage
3. Damage/loss of cartilage difficult to regenerate

Question 23

Characteristics of Interstitial Growth - Mitosis

Answer 23

1. Occurs in cartilage that lack a perichondrium i.e. epiphyseal growth plate, articular cartilage and fibrocartilage
2. Mitosis of pre-existing cells
3. Somatotropin (GH) from anterior pituitary stimulates somatomedin C from liver that stimulates mitosis of chondroblasts and chondrocytes

Question 24

Hyaline Cartilage has the following features:

Answer 24

1. avascular
2. surrounded by perichondrium (except in articular cartilage). The perichondrium has an outer fibroud layer, an inner chondrogenic layer and blood vessels
3. consists of chondrocytes surrounded by territorial and interterritorial matrices containing type II collagen interacting with proteoglycans.
4. it occurs in the temporary skeleton of the embryo, articular and the cartilage of the respiratory tract (nose, larynx, trachea and bronchi) and coastal cartilages.

Question 25

Elastic cartilage has the following features:

Answer 25

1. avascular
2. surrounded by perichondrium
3. consists of chondrocytes surrounded by territorial and interterritorial matrices containing type II collagen interacting with proteoglycans and elastic fibers, which can be stained by orcein for light microscopy.
4. occurs in the external ear, epiglottis and auditory tube

Question 26

Fibrocartilage has the following features:

Answer 26

1. avascular
2. lacks a perichondrium
3. consists of chondrocytes and fibroblasts surrounded by type I collagen and a less rigid extracellular matrix. Fibrocartilage is considered an intermediate tissue between hyaline cartilage and dense fibrous tissue.
4. predominates in the intervertebral disks, articular disks of the knee, mandible, sternoclavicular joints and pubic symphysis