Cartilage, Bones and Joints Flashcards Preview

Hugh's Locomotor > Cartilage, Bones and Joints > Flashcards

Flashcards in Cartilage, Bones and Joints Deck (32):
1

How is endochondral bone formed?

A cartilage model is made first which is replaced by bone

1

Describe how Haversian systems form

Osteoclast bore holes in bone in areas of stress

Vessels and endosteum colonise the holes

Layers of bone are laid down from the outside in

A narrow space between the vessels and bone is left - called the Haversian canal

 

2

What type of cartilage is present in intervertebral discs?

Fibrocartilage

2

Where does most bone formation occur in relation to the growth plate?

On the shaft side edge of the plate

4

The addition of what to hyaline cartilage makes it elastic cartilage?

Elastin

4

Which type of marrow is more haemopoetically active, yellow or red marrow?

Red marrow

5

Describe Haverian systems?

Long cylindrical columns of dense bone that run parallel to lines of stress

6

Where is most red marrow present in adults?

Flat bones

6

How is the diaphysis of new long bones first formed?

The cartilage is surrounded by bone that deny it nutrients therefore it degenerates and is replaced

7

Describe the cellular organisation of the growth plate

The proximal layer consists of normal cartilage (resting zone)

Then comes dividing chondrocytes (proliferation zone)

The mature chondrocytes (maturation zone)

Zone of hypertrophic, dying chondrocytes (hypertrophic zone)

Then degenerated chondrocytes are replaced by bone

 

8

What are osteocytes?

Osteoblasts that have been entombed in bone and are responsible maintenance of bone

9

What is the major type of collagen in hyaline cartilage ECM?

II

10

What is contained in the periosteum?

Fibroblasts

Connective tissue

Blood vessels

11

Is there periosteum in joints?

No

12

Where are osteoprogenitor cells located?

Periosteum

Endosteum

13

How does the composition of the nucleus propulsus change with age?

The gelatinous material - predominantly collagen type II is replaced by fibrocartilage after the age of 20

13

What do osteoprogenitor cells look like?

Flattened cells

14

Describe the blood supply of bones?

Arteries end through the compact bone and branch inside the marrow to supply a larger area of bone from the inside

 

The periosteum has a separate blood supply

 

The epiphysis and diaphysis have a separate bone supply

16

What is tartrate-resistant acid phosphatase?

A blood marker of osteoclast activity that can be measured

18

What is synovial fluid derived from?

It's an ultrafiltrate of blood with added carbohydrates

19

Which structures contain elastic cartilage?

Ears

Ear canals

Epiglottis

 

21

How do osteocytes communicate with vessels in the trabecular bone structure?

They send out processes that communicate directly with them

22

Why is the synovial membrane so leaky?

It lacks basement membrane, tight junctions and desmosomes

23

What are Sharpey's fibres?

Collagen fibres of tendons and ligaments that penetrate the bone surface and are continuous with collagen of the bone

24

Contrast the periosteum and endosteum?

Endosteum is thinner but contains more osteoprogenitor cells

26

What are the implications of the high nerve supply of bones?

Breaks are very painful

27

What structures have fibrocartilage?

Solid joints

Menisci

Intervertebral discs

28

Describe woven bone

New bone that forms during development and repair 

More vascular and cellular

Lacks Haversian systems - is replaced by them

29

Are osteoclasts more related to osteoblasts or macrophages?

Macrophages

30

What is membrane bone?

Bone that developed directly from mesenchyme

eg the skull, bones of the face

31

What is the synovial membrane?

A layer of soft tissue between the joint capsule and the joint cavity

32

What is the role of chondronectin in hyaline cartilage ECM?

Binds all the components togethers