ToB - cartilage

Question 1

what is cartilage?

Answer 1

a specialised avascular CT (no blood supply)

forms scar tissue

Question 2

which cells does cartilage consist of?

Answer 2

chrondroblasts (forms chondrocytes) & chondrocytes (mature cells)
collagen fibres (type 2)
dense ground substance

Question 3

what provides collagen with nutrients?

Answer 3

perichondrium (top & bottom layers)

through diffusion

Question 4

what are the 3 subtypes of cartilage?

Answer 4

hyaline, fibrocartilage, elastic

Question 5

where is hyaline cartilage found? facts about it?

Answer 5

most common type
abundance of type II collagen
found in:
C-shaped cartilage rings in trachea
sternal end of ribs
nasal septum

Question 6

what is hyaline cartilage used as?

Answer 6

precursor to long bone in endochondral ossification and articular cartilage in joints

Question 7

what happens to cartilage with age?

Answer 7

calcify

Question 8

how does hyaline cartilage develop?

Answer 8

1. interstitial growth: chondrocytes –> isogenous (deep in cartilage)
2. perichondrium (non-articulating surfaces (develop joint capsule) - appositional growth
   chondrocytes –> cartilage (growth from edge)
   contains fibroblast like cells –> chondroblast (secretes matrix) –> chondrocytes (matrix becomes) –> growing cartilage

Question 9

what is appositional growth?

Answer 9

fibroblast like cells –> chondroblasts –> chondrocytes

Question 10

what is interstitial growth?

Answer 10

chondrocytes –> isogenous groups (group of chondrocytes - deep into cartilage)

Question 11

what is the perichondrium?

Answer 11

the dense irregular connective surrounding the hyaline cartilage
contains chondrogenic cells

Question 12

what does extracellular matrix contain?

Answer 12

lots of collagen and elastin

Question 13

where are chondrocytes aggregated in?

Answer 13

lie in lacuna

Question 14

what are the 2 types of matrix within cartilage and how do they appear?

Answer 14

territorial matrix - darker, more sulphate

interterritorial matrix - lighter

Question 15

what does elastic cartilage contain? does it ossify? where is it found? what is it abundant in?

Answer 15

contains elastic fibres and elastic lacunae
does NOT ossify with ageing
found in external ear (pinna), epiglottis, Eustachian tube, external acoustic meatus
abundant elastin stains dark in H&E

Question 16

what does fibrocartilage contain? where is it found? what does it not have?

Answer 16

more type I collagen, less chondrocytes, contains fibroblasts
found in IV disks, knee joints (menisci) and pubic symphysis, sternoclavicular & temporomandibular joints
no perichondrium (top / bottom layers)
attach bone –> tendon , stained green
dense regular + hyaline cartilage
lie in hyaluronate proteoglycan aggregate (like cytoplasm)