1. Joints occur wherever two bones meet.

2. 3 Structural and Functional Classifications of Joints:
A. Synarthroses: These are fixed or immovable joints
Fibrous: two bones are connected directly to each other by fibrous connective tissue.
There are 3 kinds of fibrous joints:
Syndesmosis: fibrous tissue connects two bones that work together as a unit
Example: tibia and fibula; radius and ulna
Suture: interlocking seams between bones
Ex. Sutures of the skull
Gomphosis: a peg and socket joint
Ex. How teeth connect to their sockets

3. (b) Syndesmosis Joint held together by a ligament.
Fibrous tissue can vary in length, but
is longer than in sutures.
Fibula
Tibia
Ligament
Figure 8.1b

4. Joint held together with very short,
(a) Suture
Joint held together with very short,
interconnecting fibers, and bone edges
interlock. Found only in the skull.
Suture
line
Dense
fibrous
connective
tissue
Figure 8.1a

5. (c) Gomphosis “Peg in socket” fibrous joint. Periodontal
ligament holds tooth in socket.
Socket of
alveolar
process
Root of
tooth
Periodontal
ligament
Figure 8.1c

6. B. Amphiarthroses: These joints are partially movable.
Cartilaginous: fibrocartilaginous pads separate two bones.
There are 2 kinds of cartilaginous joints:
a. Synchondrosis
Ex. epiphyseal plates
b. Symphysis
Intervertebral disks; pubic symphysis

7. Bones united by hyaline cartilage
(a) Synchondroses
Bones united by hyaline cartilage
Sternum
(manubrium)
Epiphyseal
plate (temporary
hyaline cartilage
joint)
Joint between
first rib and
sternum
(immovable)
Figure 8.2a

8. Bones united by fibrocartilage
(b) Symphyses
Bones united by fibrocartilage
Body of vertebra
Fibrocartilaginous
intervertebral
disc
Hyaline cartilage
Pubic symphysis
Figure 8.2b

9. C. Diarthroses: These joints are fully movable
Synovial:
i. There are 6 kinds of synovial joints
Plane (gliding) joint: 2 bones slide past each other
Ex. Carpals and tarsals
Pivot joint: one bone rotates around another
Ex. Radioulnar joint
Saddle joint: oval bone rests in a concave depression in another bone
Ex. Thumb and triquitrium
Hinge joint: allows for extension and flexion only
Elbow and interphalangeal joints
Condyloid (Ellipsoid) joint: allows for angular motion in two directions
Knee, TMJ and neck
Ball and socket: a round head fits in a depression in another bone
Allows for greatest range of motion
Shoulder and hip

10. (a) Gliding movements at the wrist
Figure 8.5a

11. (a) Pronation (P) and supination (S)
(radius
rotates
over ulna)
Supination
(radius and
ulna are
parallel)
(a) Pronation (P) and supination (S)
Figure 8.6a

12. Saddle

13. Hinge

14. condyloid

15. Ball-and-socket joint (shoulder joint)f
Nonaxial
Uniaxial
Biaxial
Multiaxial c b f
Ball-and-socket joint (shoulder joint) a e d
Figure 8.7f

16. All Synovial joints have the following parts:
Articular cartilage
Hyaline cartilage that cushions the ends of bones in the appendicular skeleton
Only synovial joint in the axial skeleton is the temporomandibular joint (TMJ) or jaw
Articular cartilage helps reduce friction when joints move.
Synovial fluid
Slippery fluid that occupies the space between bones in the joint cavity
Lubricates the articular cartilage
Stored in the bursa: membranous sacs that make and store synovial fluid
Located between tendons and bones and between ligaments and bones

17. iii. Joint capsule iv. Joint cavity v. Ligaments Surrounds the joint
Made of dense regular connective tissue
Creates a sealed cavity between the bones
iv. Joint cavity
Found inside the joint capsule
Filled with synovial fluid
v. Ligaments
Connect bone to bone
Intrinsic ligaments are found inside the joint
Ex. ACL and PCL in the knee; ligamentus capitus in hip
Extrinsic ligaments are found outside the joint
Ex. MCL and LCL of knee

18. Synovial Joints: Range of Motion
1. Nonaxial—slipping movements only
2. Uniaxial—movement in one plane
3. Biaxial—movement in two planes
4. Multiaxial—movement in or around all three planes