Classification of joints & joint terminology

Question 1

Synovial joints

Answer 1

Any movable joint
Movement of bones is lubricated by articular cartilage and synovial fluid which is secreted by the synovial membrane.

Question 2

Components of a synovial joint.

Answer 2

Synovial cavity, synovial membrane, joint capsules, articular/hyaline cartilage, ligaments, and synovial fluid.

Question 3

Articular capsule

Answer 3

Tough fibrous tissue - resists tensile force & thus dislocation
Sleeve connecting the articulating bones
Flexible to allow movement
Inside lined with synovial membrane

Question 4

Articular cartilage

Answer 4

Hyaline cartilage that covers ends of articulating bones in synovial joints
This makes a frictionless coat, which also acts as a shock absorber.

Question 5

Synovial Membrane

Answer 5

Secretes synovial fluid and surrounds the synovial cavity.

Question 6

Synovial Fluid

Answer 6

Lubricates & provides nourishment to cartilage

Question 7

Ligaments

Answer 7

Part of the fibrous membrane surrounding the synovial membrane.
Attach bones either side of the joint together in the joint capsule.
Their specific attachment sites allow them to resist certain movements.

Question 8

Articular / Intra-articular discs

Answer 8

White fibrocartilage
Helps with movement and joint congruency

Question 9

Bursa

Answer 9

Sac-like structures filled with fluid similar to synovial
reduces joint friction

Question 10

Types of synovial joint

Answer 10

planar, hinge, pivot, saddle, ball & socket, ellipsoid, condyloid

Question 11

Planar joint surface

Answer 11

joint surface is flat & of equal extent

Question 12

Planar joint movement

Answer 12

A single glide / twist of one bone against another in the same plane as the articular surfaces

Question 13

Hinge joint surface

Answer 13

2 articular surfaces that “fit”

Question 14

Hinge joint movement

Answer 14

allow movement in one axis / plane

Question 15

Pivot joint surface

Answer 15

One bone rotates within a fibro-osseous ring

Question 16

Pivot joint movement

Answer 16

Movement occurs about a single axis

Question 17

Saddle joint surface

Answer 17

Reciprocally concavoconvex
like a rider sitting on a saddle

Question 18

Saddle joint movement

Answer 18

Movement occurs about 2 mutually perpendicular axes & a smaller movement about a 3rd axis

Question 19

Ball and socket joint surface

Answer 19

“Ball” of one bone fits into the “socket” of another

Question 20

Ball and socket joint movement

Answer 20

Movement around 3 principal mutually perpendicular axes

Question 21

Ellipsoid joint surface

Answer 21

ellipsoid = Oval ball & socket

Question 22

Ellipsoid joint movement

Answer 22

movement about 2 perpendicular axes

Question 23

Condyloid joint surface

Answer 23

Ovoid articular surface, or condyle that is received into an elliptical cavity

Question 24

Condyloid joint movement

Answer 24

Active: about 2 perpendicular axes
Passive: about a 3rd axis

Question 25

Fibrous joints - function & 3 types

Answer 25

Designed for stability rather than movement
1) suture - between bones in skull
2) syndesmosis - two parallel bones are joined by fibrous connective tissue
3) gomphosis - anchors the root of a tooth into its bony socket within the maxillary bone (upper jaw) or mandible bone (lower jaw) of the skull.

Question 26

Cartilaginous joints & types

Answer 26

2 bones joined by a continuous pad of cartilage
Types: primary & secondary

Question 27

Secondary cartilaginous joint features

Answer 27

Occurs in the midline
Allows a small amount of controlled movement
Articular surfaces covered by hyaline cartilage which sandwich a pad of fibrocartilage