MSK Cartilage

Question 1

What are the three types of cartilage?

Answer 1

1. hyaline
2. elastic
3. fibrocartilage

Question 2

Where is this tissue found in the human body?

Answer 2

• tracheal rings
• nose
• bronchi
• moveable joints (articulating surfaces)

(cartilage can bear mechanical stress without aprreciable distortion)

Question 3

Chondroblasts arise from _____cells and begin secreting _____of cartilage.

Answer 3

• mesenchymal
• matrix material

Question 4

________ envelopes cartilage and is responsible for its growth and maintenance.

Answer 4

Perichondrium

(fibroblasts are associated with the outer fibrous layer & chondrogenic cells are associated with the inner cellular layer)

Question 5

What are the major cell types present in developing hyaline cartilage?

Answer 5

1. mesenchyme cells
2. chondroblasts
3. fibroblasts
4. chondrogenic cells

Question 6

The outer fibrous layer of the perichondrium has which components?

Answer 6

• Fibroblasts
• type 1 collagen
• blood vessels

(fibroblasts differentiate from the mesenchymal cells present at the peripheral edge of the developing cartilage.)

Question 7

Which cell type comprises most of the inner cellular layer of the perichondrium?

Answer 7

chondrogenic cells

(can differentiate into chondroblasts)

Question 8

Define chondrocytes

Answer 8

Former chondroblasts that have completely surrounded themselves in matrix.

Question 9

Define Isogenous groups.

Answer 9

Small clusters of chondrocytes present in the central (mature) region of cartilage.

(result of chondrocyte mitosis)

Question 10

What is the circle in the photo?

Answer 10

Isogenous group

M= matrix, C = chondrocytes in lacunae

Question 11

What do the brackets indicate?

Answer 11

perichondrium

M= matrix, C = chondrocytes in lacunae

Question 12

What are the major matrix components of hyaline cartilage?

Answer 12

• collagen
• glycosaminoglycans
• chondronectin

Question 13

Why does type II collagen appear as a non-fibrillar homogenous mass under light microscope?

Answer 13

• same refractive index as the ground substance
• fiber orientation dictated by direction of stress
• fibers are fine

Question 14

What are the major glycosaminoglycans in cartilage?

Answer 14

• chondroitin 4-sulfate,
• chondroitin 6-sulfate
• keratan sulfate

Question 15

Basophilic staining of the cartilage matrix is due to the staining of what substance?

Answer 15

glycosaminoglycans

Question 16

Define chondronectin

Answer 16

glycoproteins that binds cells in the matrix

(Binds matrix components and integrins on chondroblasts and chondrocyte membranes)

Question 17

What is the main difference between elastic cartilage and hyaline cartilage

Answer 17

they are the same, except elastic cartilage has more elsatic fibers & type II collegen in prominent.

(elastic cartilage of earlobe)

Question 18

What would you stain elastic fibers with?

Answer 18

orcein

Question 19

What is the function of elastic cartilage?

Answer 19

resiliency

structure the external ear, epiglottis & larynx

Question 20

Describe the development of fibrocartilage.

Answer 20

fibroblasts secrete proteoglycans, surrounding themselves in matrix, then differentiate into chondrocytes (withou perichondrium).

Question 21

Describe the characteristics of fibrocartilage.

Answer 21

• little cartilage matrix present
• parallel type I collagen fibers are packed together in bundles with chondrocytes wedged in rows between them.

Question 22

What is the function and location of fibrocartilage?

Answer 22

high tensile strength (large type I collagen bundles)

pubic symphysis

tendons and ligaments

(picture of IV disc. fibroblasts have elongated nuclei; chondrocytes have dark round nuclei. Inset: chondrocytes contained within lacunae)