1.1 Basic anatomy

Question 1

What are synathroses and Amphiarthroses?

Answer 1

Syn: an interlocking suture line between adjacent bones

Amp: fibrocartilage between adjacent bones

Question 2

What are the 3 types of synovial joints?

Answer 2

Hinge, ball and socket and saddle

Question 3

What is the synovium and what does it not cover?

Answer 3

The internal lining of the joint, does not cover the cartilage or meniscus unless it is pathological

Question 4

What are the layers of the synovium and what is their function?

Answer 4

Inner: synoviocytes which are 3 cells thick and produce hyaluronic acid

Outer: subintima which produces fibroblasts

Question 5

What is synovial fluid and what does it carry?

Answer 5

An ultrafiltarte of blood which has the hyaluronic acid to increase viscosity to allow the sliding of bones.

Acts as a lubricant and nutrient transport

Question 6

What is synovitis?

Answer 6

An immune attack on the synovium such as that seen in RA

Question 7

What happens in early RA?

Answer 7

oedematous, thickened, hyperplastic projections. Dense infiltration with inflammatory cells

Question 8

What happens in late RA?

Answer 8

Pannus formation - hyperaemic, fibrovascular granulation tissue in the joint causing loss of bone and cartilage

Question 9

What is the role of fibrocatilage?

Answer 9

Attaches tendons and ligaments to bone

Question 10

Where is fibroelastic cartilage located?

Answer 10

IV discs and intraarticular menisci (load bearing and shock absorption)

Question 11

Where is articular cartilage located, what is its function and what are the key cells?

Answer 11

Locates at the ends of bones in synovial joints and acts as a shock absorber. The main cell type is the chondrocytes which synthesise the ECM (ground substance)

Question 12

What type of collagen is in articular cartilage and what is its orientation

Answer 12

Type 2 collagen

Superficially they run parallel to the surface, intermediate no direction and deep they are vertical

Question 13

Where do the collagen fibres come from in the articular cartilage?

Answer 13

they hold down the articular cartilage to the calcified cartilage which is related to the subchondral bone

Question 14

What is the tidemark?

Answer 14

Where the calcified and normal cartilage meet

Question 15

What are the components of ground substance and what is their function?

Answer 15

proteoglycan and elsatin
Act to bind the water in the cartilage, if you have degeneration in this you will lose water in the cartilage and the force that they transmit is lost leaving the force to be transmitted into the subchondral bone which has pain fibres

Question 16

What cells secrete proteoglycans?

Answer 16

Chondroitin and keratin sulphate

Question 17

Where are the 5 main types of collagen located?

Answer 17

1: skin, fascia, tendon, ligament, bone
2: cartilage
3: skin, artery and uterus (in combination with 1)
4: basement membrane
5: placenta and blood vessels

Question 18

what is the function of collagen?

Answer 18

Determines the tensile strength of tissues
Provides a framework
Limits movement of other tissue components
Induces platelet aggregation and clot formation
Regulates hydroxyapatite deposition in bone

Question 19

What is the composition of ligament and what is its function?

Answer 19

Dense collagenous tissue with rows of fibroblasts within and ECM of type 1 collagen fibres with elastin to allow for stretch
Function: to prevent excessive movement

Question 20

What is the role of a tendon?

Answer 20

Carry tensile forces and store energy

injury: tears or degenration

Question 21

What is the structure of a tendon?

Answer 21

parallel layers of collagen embedded in a matrix of proteoglycans

Question 22

What happens in degeneration of tendons

Answer 22

There are no inflammatory cells leading to collagen fibre disorganisation and separation (microtears)

Question 23

What is the structure and function os tenon sheath?

Answer 23

outer fibrotic layer and inner synovial layer with synovial fluid between the layers
Acts to reduce friction

Question 24

What is paratenon and epitenon?

Answer 24

Paratenon: loose, arolar conective tissue around tendons
Epitenon: fine connective tissue sheath covering the tendon

Made of type 1 and 3 collagen fibres

Question 25

What is the enthesis and what are the 4 zones?

Answer 25

Attachment point of the tendon/ligament to bone
Tendon/ligament, fibrocartilage, mineralized fibrocartilage and bone

The collagen bundles of the tendon continues into the fibrocartilage and the tidemark will separate this from the mineralized fibrocartilage