Cartilage

Question 1

Where do we find cartilage?

Answer 1

• Embryo: skeleton intially mostly cartilage, bones replace during fetal development/childhood
• Adult: skeleton (e.g. costal cartilage (hyaline) in ribcage), nose, external ear, trachea and larynx

Question 2

What is cartilage (structure, function, characteristics)?

Answer 2

• Semi-rigid, flexible connective tissue
• Support in tissues/organs and scaffolding for bone development
• Avascular and aneural - obtains nutrition by long range diffusion from blood vessels on its periphery
• High-mechanical strength

Question 3

What is cartilage composed of?

Answer 3

CT so:
1. Cells - chondroblasts and chondrocytes
2. ECM - water, mixture of molecules, fibres

Question 4

What are the 3 types of cartilage?

Answer 4

1. Hyaline
2. Elastic
3. Fibrocartilage

Question 5

Where can hyaline cartilage be found

Answer 5

Articular, costal and nasal cavities, larynx, trachea, bronchi and epiphyseal growth plates

Question 6

What is the appearance of hyaline cartilage and how strong is it?

Answer 6

Glassy appearance - weakest type of cartilage

Question 7

How do the different types of carticalge differ from each other?

Answer 7

In compostion of ECM and number of cells

Question 8

What is the composition of hyaline cartilage like?

Answer 8

type II collagen fibres, proteoglycans, glycoproteins, and extracellular fluid. + chondrocytes (cells)

Question 9

Where is elastic cartilage found

Answer 9

external ear, larync and epiglottis (maintains shape)

Question 10

What are some features of elastic cartilage

Answer 10

Flexible but resistant

Question 11

What does elastic cartilage contain?

Answer 11

Chondrocytes, elastic and collagen fibres, matrix is composed of glycosaminoglycans, proteoglycans and multiadhesive glycoproteins

Question 12

Where is fibrocartilage found?

Answer 12

In joint capsules, ligament/tendon insertions (into bone) and intervertebral discs

Question 13

What is the composition of fibrocartilage

Answer 13

Chondrocytes + Alternating layers of hyaline cartilage matrix and dense bundles of (type 1) collagen fibres - no perichondrium

Question 14

What is the perichondrium

Answer 14

a dense layer of fibrous connective tissue that covers the surface of most of the cartilage in the body. The perichondrium consists of an outer fibrous layer that contains fibroblasts and an inner chondrogenic layer that contains chondroblasts.

Question 15

How strong is fibrocartilage

Answer 15

Strongest type

Question 16

What are the properties of cartilage in terms of blood supply and how does this affect cartilage’s structure?

Answer 16

Avascular (although carticage channels = pores from B-vessels into cartilage matrix), and since most cells distant from vascular supply, diffusion must occur from surface (perichondrial) vessels to cells. - Cartilage thus is limited to a few mm thick and does not regenerate well/at all (no O2/nutrients)

Question 17

Articular cartilage

Answer 17

Type of hyaline cartilage: smooth, white tissue that covers the ends of bones where they come together to form joints. Obtains its nutrients from synovial fluid, but doesn’t heal itself well so damage/wear and tear causes it to degrate and stop smooth movement of bones

Question 18

What can happen to carticage in terms of ageing

Answer 18

Water content dec:
- dec shock absorption
- less protection of articular surfaces —> inc risk of damage

Question 19

Which cartilage types have a perichondrium

Answer 19

Hyaline and elastic

Question 20

Chondrocytes

Answer 20

Chondrocytes are the cells responsible for cartilage formation, and they are crucial for the process of endochondral ossification, which is useful for bone development. - mainly responsible for the production of collagen and the extracellular matrix that will lead to the maintenance of cartilaginous tissues within joints.
- only cells found in healthy cartilage

Question 21

how do the 3 types of cartilage differ

Answer 21

In relative amounts of callagen, elastic fibres and ground substane/matrix