Lecture 5

Question 1

What is a young cell?

Answer 1

Osteoblast

Question 2

Is there elastic in bone?

Answer 2

only INSIDE bone

Question 3

What are the 2x components of Connective Tissue?

Answer 3

Cells and ECM

Question 4

What are the 5x components of ECM?

Answer 4

Fibres
Matrix
Glycoproteins
Tissue Fluid
Hydroxyapatite

Question 5

What colour does Cancellous bone stain?

Answer 5

dark purple

Question 6

What colour does bone marrow stain?

Answer 6

light purple

Question 7

What are features of bones of the vertebral bodies?

Answer 7

Fine webs of bone
Preferential alignment upwards - indirection of head
Small shafts running sideways, creating a network
Periosteum fibrous tissue on outside

Question 8

Periosteum

Answer 8

Peri- = outside
osteum = osteogenic properties
Thicker and more fibrous
contains OSteoblasts

Question 9

Cancellous bone

Answer 9

Trabeculae smallest element
Trabeculae surrounded by bone marrow
Osteocytes in lacunae

Question 10

What do histological sections of lacunae look like?

Answer 10

often empty

as the cells have fallen out

Question 11

Endosteum

Answer 11

Thinner and less collagen fibre
More in adult bone
Cells dont do much

Question 12

Compact bone

Answer 12

markedly thicker
Osteons not located near surface - as blood supply is sourced from Peri and endosteum
finger like process

Question 13

What layers (collective name) contain osteoblasts?

Answer 13

Osteogenic layers

-both periosteum and endosteum

Question 14

What sound can you hear when you pull of periosteum?

Answer 14

cracking
fibres running at 90degrees breaking
-cannot pull endosteum off as is too thin

Question 15

Where are the 2x types of osteoblast growth?

Answer 15

1. Osteoblasts Closest to bone, surrounds itself with matrix, incorporating itself in bone and becoming part of new bone by secreting hydroxiapatite and collagen themselves
2. Maintain and Remains part of the osteogenic layer

Question 16

When has an osteoblast completely transitioned to become a mature cell osteocyte?

Answer 16

Once it has matrix hydroxyapatite and collagen surrounding it Completely

Question 17

Collagen fibrils in histology slide

Answer 17

large numbers in matrix
Produced and secreted by osteoblasts
Cut in cross section (transversely) are coming out of the page - therefore appear to be dots

Question 18

What is the blotches of dark staining material in a bone histology slide?

Answer 18

dark staining material
crystal
seeds into collagen fibres

Question 19

What are the features of bone?

Answer 19

Bone is good under tension, compression and torsion
Strong
Lightweight
Dynamic-remodel

Question 20

What does hydroxyapatite allow resistance to?

Answer 20

pressure and torsion

Question 21

What is the relative amount of PG in bone?

Answer 21

Small
as is rigid and isnt depressed
only PG is Decorin which allows for alignment of colagen

Question 22

What are glycoproteins?

Answer 22

small molecules that help bind other matrix molecules together
Osteonectin