Cartilage

Question 1

Characteristics of cartilage:

Answer 1

-avascular
-no nerve supply or lymphatics
-extracellular matrix

Question 2

What are the cells of cartilage?

Answer 2

chondroblasts or chondrocytes

Question 3

What are the functions of cartilage?

Answer 3

-bear mechanical stresses without distortion
-shock absorber
-frictionless movement at joints
-bone repair
-fracture repair

Question 4

What the three types of cartilage?

Answer 4

hyaline
elastic
fibrocartilage

Question 5

What is perichondrium?

Answer 5

dense connective tissue interface around hyaline and elastic cartilage
-carry blood supply
-source of new cartilage cells

Question 6

What are fibrogenic cells?

Answer 6

outer perichondrium, become fibroblasts and give rise to fibers and ground substance

Question 7

What are chondrogenic cells?

Answer 7

inner perichondrium, give rise to chondroblasts and osteoprogenitor cells

Question 8

When are chondroblasts formed?

Answer 8

when there is not high amounts of oxygen

Question 9

When are osteoprogenitors formed?

Answer 9

where there is oxygen present

Question 10

What are chondroblasts?

Answer 10

replicating cells that secrete cartilaginous extracellular matrix
-flatter cells with large nucleus

Question 11

What are chondrocytes?

Answer 11

round cells with small, dark nuclei
-often in groups of 2-8 cells (isogenous groups)

Question 12

What are chondroclasts?

Answer 12

cells in cartilage that is removing calcified cartilage
-appear to enter cartilage with vasculature

Question 13

What does the matrix of cartilage do?

Answer 13

resist compressive forces

Question 14

What are the components of cartilage matrix?

Answer 14

fibers (collagen) and GAGs

Question 15

What are proteoglycans?

Answer 15

core proteins with GAG side chains

Question 16

What is the most abundant monomer of GAGs in proteoglycans?

Answer 16

aggrecan

Question 17

What causes the gel like consistency of matrix of cartilage?

Answer 17

electrostatic bonds between collagen fibers and GAG side chains
-bind of water to GAGs

Question 18

What attach matrix components to one another?

Answer 18

glycoproteins

Question 19

What are the glycoproteins associated with matrix?

Answer 19

link proteins, fibronectin, and chondronectin

Question 20

What do chondronectin bind to?

Answer 20

C-4 and C-6 sulfates , HA and integrins

Question 21

What is the territorial matrix?

Answer 21

matrix found around each chondrocytes
-high amounts of GAGs and low collagen

Question 22

What is the inter-territorial matrix?

Answer 22

surrounds the territorial matrix
-more collagen II, fewer proteoglycans

Question 23

What forms the consistency of hyaline cartilage?

Answer 23

extensive cross linkinh

Question 24

What do proteoglycans associate with in hyaline cartilage?

Answer 24

collagen II fibrils

Question 25

What surrounds hyaline cartilage? (except for in articular surfaces)

Answer 25

surrounded and nourished by perichondrium

Question 26

Where is hyaline cartilage?

Answer 26

-temporary skeleton in embryo -epiphyseal plates

Question 27

What causes growth of hyaline cartilage?

Answer 27

hormones

Question 28

What causes abnormal growth and calcification of hyaline cartilage?

Answer 28

hormones and vitamins

Question 29

What is a characteristic of elastic cartilage?

Answer 29

increased flexibility -returns to original shape after deformation

Question 30

Where is elastic cartilage found?

Answer 30

auricle, auditory tube, ear, epiglottis, and laryngeal cartilages

Question 31

Characteristics of fibrocartilage:

Answer 31

-no perichondrium -chondrocytes in rows -abundant collagen I and II -ground substance has dermatan and chondroitin sulfate

Question 32

Where is fibrocartilage found?

Answer 32

ligaments, articular surfaces, symphysis pubis, menisci, labrum, intervertebral discs

Question 33

What can form due to damage in hyaline cartilage?

Answer 33

fibrocartilage

Question 34

What is appositional growth?

Answer 34

new cartilage forming on surfaces of pre-existing cartilage

Question 35

Where does appositional growth occur?

Answer 35

inner layer of perichondrium

Question 36

What do chondrogenic cells make?

Answer 36

collagen I (in perichondrium)

Question 37

What do chondroblasts secrete?

Answer 37

collagen II and ground substance

Question 38

What are the stages of interstitial growth?

Answer 38

take place within cartilage mass itself -chondrocytes divide within lacunae (make more isogenous groups) -chondrocytes secrete more matrix, which increase mass of cartilage -overall growth due to secretion of new matrix

Question 39

What limits interstitial growth?

Answer 39

avascular nature

Question 40

What typically repairs damaged cartilage?

Answer 40

perichondrium

Question 41

Are a lot of chondrocytes produced in adulthood?

Answer 41

no, few are produced

Question 42

What replaces cartilage?

Answer 42

dense connective tissue or bone (if vascularized)

Question 43

What stimulates bone growth instead of cartilage repair?

Answer 43

proximity of blood vessels