Joints

Question 1

Defintion

Answer 1

The union of two bones- but do not imply movement as some are specialised to permit little-no movement

Question 2

What are the different types of joint

Answer 2

Synovial
Cartiligneous- united by cartilage
Fibrous- united by collagen

Question 3

Describe fibrous joints

Answer 3

United by collagen

Sutures
Syndesome
Gomphosis

Question 4

Describe sutures

Answer 4

found between skull bones

in foetal skulls- the sutures are wide and and bones are present in smooth opposing surface- slight movement during the passage of the head through birth canal
the growth of the skull completes and the sutures are more rigid- no movement in between the articulating bones

eg. squamous, serrated and denticulate

Question 5

Describe Syndesomes

Answer 5

2 bony components are slightly apart and are united by INTEROSSEOUS membrane- little movement

Question 6

Describe Gomophosis

Answer 6

Form of a peg in a socket- fibrous tissue is arranged Inas periodontal ligament

eg root of tooth in jaw

Question 7

Describe cartilaginous joints

Answer 7

Primary- Synchondroses

Secondary- symphysis

Question 8

Describe synchondroses

Answer 8

These joints develop between bones of endochondral origin- it is defined by the solid plate of hyaline cartilage between opposing surfaces.
This plate acts as an epiphyseal plate between primary and secondary ossification of long bones

Question 9

Describe symphysis

Answer 9

Partially moveable joint in which opposing surfaces are covered by hyaline cartilage but separated by intervening fibrous tissue- found in the midline of the body

Question 10

Describe synovial joints-

Answer 10

moveable joints that all have 4 common features and 2 not always there:

the ends of the bone are covered in articular hyaline cartilage
presence of joint cavity
joint capsule
synovial membrane

DISC
BURSAE

Question 11

Articular Cartilage

Answer 11

The ends of the bone are covered in hyaline cartilage as bone is not a suitable tissue for opposing surfaces

The fact that bones are rigid means that forces are transmitted over a small area- huge stress-
The cartilage is TOUGH BUT DEFORMABLE- its elastic properties allows it to regain its origin when force is removed

Question 12

Joint cavity

Answer 12

The ends of the bone seperated by a joint cavity which contains synovial fluid

Question 13

Joint Capsule

Answer 13

surrounds the joint like a sleeve

consists of bundles of collagen fibres- varying in toughness and thickness

Question 14

Synovial Membrane

Answer 14

Capsule lined by the synovial membrane
Has a rich bloody supply
Can secrete and absorb fluid
The viscosity of the fluid changes with speed of joint movement- ie when it is thin, its speed will be high

Question 15

Disc

Answer 15

Interposed between articular surfaces- divides the join into two cavities
Allows for the big range of movements
Increases the congruency of the joint, spreading the loading of the whole joint surface

Question 16

Bursae

Answer 16

sacs filled with synovial fluid- wither continue with synovial membrane or close to join

Question 17

Name the different types of shapes of joints -proximal to distal

Answer 17

pivot
ball and socket- head of femur and acetabulum of the hip bone.
hinge- head of radius and radius notch of ulna
condyloid
ellipsoid
saddled
gliding

Question 18

What is the direction and range of movement dependant on ?

Answer 18

shape of joint surface
tension of joint capsule
position of capsular ligaments
MUSCLE