Joints, Synovial Fluid and Cartilage

Question 1

3 basic types of joints

Answer 1

Fibrous
Cartilaginous
Synovial

Question 2

3 Fibrous joints

Answer 2

Periodontal Ligament
Cranial Sutures
Interosseus Membranes

Question 3

2 types of cartilaginous joints

Answer 3

Primary and Secondary

Question 4

Describe a Primary cartilaginous joint and give an example of one

Answer 4

Only hyaline cartilage

Growth plates

Question 5

Describe a Secondary Cartilaginous joint and give an example of one

Answer 5

Hyaline AND fibrocartilage

Intervertebral Disc

Question 6

Common features of a synovial joint

Answer 6

Articular Cartilage
Fibrous Capsule
Synovial Membrane
Synovial Cavity + Synovial fluid

Question 7

What MAY synovial joint also contain

Answer 7

Articular Discs
Ligaments
Bursae

Question 8

6 types of synovial joint and examples of each

Answer 8

Plane - Intervertebral 
Hinge - Elbow (proper name for joint)
Pivot - ?
Condylar (ellipsoid) - 1st vertebra?
Saddle - Thumb?
Ball and socket - Shoulder

Question 9

What Glycoprotein, Proteoglycan and Glycosaminoglycan are related to hyaline cartilage

Answer 9

Glycoprotein - Lubricin
Proteoglycan - Aggrecan
Glycosaminoglycan - Hyaluronic Acid

Question 10

What layer hyaline cartilage produces Lubricin

Answer 10

Superficial/Tangential layer

Question 11

What layer of hyaline cartilage produces Aggrecan

Answer 11

Transitional layer

Question 12

What structure produces Lubricin and Aggrecan

Answer 12

Lubricin - Flattened Chondrocytes

Aggrecan - Round Chondrocytes

Question 13

What layer of hyaline cartilage produces Collagen

Answer 13

Superficial/Tangential layer

Question 14

What changes from Superficial to Deep layer of Hyaline Cartilage

Answer 14

Orientation of collagen

Question 15

What feature of cartilage makes supplying nutrients difficult and how is this overcome

Answer 15

It’s avascular

Synovial Fluid => Direct exchange of CO2 and metabolites between blood and synovial fluid

Question 16

What produces Synovial Fluid

Answer 16

Synoviocytes

Question 17

2 types of Synoviocytes

Answer 17

Type A

Type B

Question 18

Describe Type A Synoviocytes

Answer 18

Look like Macrophages
Remove debris
CONTRIBUTE to synovial fluid production

Question 19

Describe Type B Synoviocytes

Answer 19

Fibroblast like

MAIN producer of synovial fluid

Question 20

What is synovial fluid composed of

Answer 20

Hyaluronic Acid and Lubricin (fluid component?water?)

Question 21

Volume of synovial fluid in knee joint and turnover

Answer 21

~0.5ml

~2 hours

Question 22

Functions of synovial fluid

Answer 22

Nutrition of cartilage
Removal of waste products
Lubrication => less friction => less wear

Question 23

Describe the 3 methods of Lubrication

Answer 23

Boundary - Lubricin binds to receptors on ARTICULAR SURFACES forming a THIN FILM
Hydrodynamic - Surfaces kept apart by liquid pressure (like aquaplaning) (viscosity changes with load and velocity of movement)
Weeping

Question 24

Describe the 3 methods of Lubrication

Answer 24

Boundary - Lubricin binds to receptors on ARTICULAR SURFACES forming a THIN FILM
Hydrodynamic - Surfaces kept apart by liquid pressure (like aquaplaning) (viscosity changes with load and velocity of movement)
Weeping - Fluid that present in the cartilage is squeezed out into the synovial cavity to increase fluid volume

Question 25

What is a bursa and where is one found

Answer 25

Small fluid-filled sac lined by synovial membrane containing viscous synovial fluid
Provides a cushion between bones and tendons and/or muscles around a joint
Helps Reduce friction
can be found in the knee

Question 26

What happens to Synovial cartilage as one ages

Answer 26

Viscosity of synovial fluid decreases => Reduced lubrication and slower joint movements
Water content of cartilage decreases => Reduced shock absorption