Histology of Cartilage

Question 1

What is mesenchyme?

Answer 1

embryonic stem cells giving rise to many other tissue types

Question 2

Why is the role of mesenchyme in cartilage formation?

Answer 2

it gives rise to all adult CT, specifically producing chondroblasts

Question 3

3 main components of cartilage

Answer 3

1. cells
2. ECM
3. Perichondrium

Question 4

Cell types in cartilage

Answer 4

1. chondroblasts

2. chondrocytes

Question 5

Chondroblasts

Answer 5

secrete ECM, come from mesenchymal stem cells

Question 6

Chondrocytes

Answer 6

maintain/produce ECM, come from chondroblasts, reside in lacunae

Question 7

What percent of cartilage is formed by ECM?

Answer 7

95%+

Question 8

Perichondrium

Answer 8

DCT capsule, covers some cartilages, contains BVs, nerves, fibroblasts, type I collagen, essential for growth/maintenance of some cartilage

Question 9

Mechanisms of cartilage growth

Answer 9

1. Appositional growth

2. Interstitial growth

Question 10

Appositional growth

Answer 10

addition to an existing surface, generation of new chondroblasts

Question 11

Interstitial growth

Answer 11

internal expansion, proliferation of chondrocytes and formation of isogenous groups

Question 12

3 types of cartilage

Answer 12

1. Hyaline cartilage
2. Elastic Cartilage
3. Fibrocartilage

Question 13

ECM component of Hyaline cartilage

Answer 13

75% water (allows for diffusion), proteoglycans, hyaluronic acid, type II collagen

Question 14

Location of Hyaline cartilage

Answer 14

articular surfaces, nose, larynx, tracheal rings, epiphyseal plates, fetal bone models

Question 15

Appearance of Hyaline cartilage

Answer 15

fresh: blue/white
histo: basophilic matrix, indistinguishable collagen fibers with H+E stain

Question 16

Territorial matrix

Answer 16

area directly surrounding isogenous groups, darker

Question 17

Interterritorial matrix

Answer 17

space between territorial matrix, lighter

Question 18

ECM component of Elastic cartilage

Answer 18

same as Hyaline, plus elastic fibers (more bendy than Hyaline)

Question 19

Location of Elastic cartilage

Answer 19

auricle, auditory canal, auditory tube, epiglottis

Question 20

Perichondrium of Hyaline cartilage

Answer 20

present

Question 21

Perichondrium of Elastic cartilage

Answer 21

present

Question 22

Appearance of Elastic cartilage

Answer 22

fresh: yellowish
histo: prominent elastic fibers with special stain

Question 23

ECM component of Fibrocartilage

Answer 23

type I collagen (like DCT), less proteoglycans than other cartilage (vvery very strong)

Question 24

Location of Fibrocartilage

Answer 24

intervertebral discs, pubic symphysis, major tendon-bone anchorages (areas that undergo pulling forces)

Question 25

Perichondrium of Fibrocartilage

Answer 25

absent

Question 26

Appearance of Fibrocartilage

Answer 26

looks like cross between DCT and hyaline cartilage, chondrocytes arranged in long rows separated by coarse collagen fibers, acidophilic matrix