1. COMMON COURSE OBJECTIVES:
CHAPTER 9 “Joints”
COMMON COURSE OBJECTIVES:
Joints: Structural and functional classification
Structure of a typical synovial joint
Types of synovial joints
Terms for descriptions of movements

2. JOINTS Defined: any place where two bones come together
General Function of Joints:
- Hold the skeleton together
- Allow for increased mobility and flexibility of skeleton

3. CLASSIFICATION OF JOINTS
Joints can be classified based on:
-function (what kind of movement they allow)
-structure (what material is found in the joint and if is there a joint cavity present).
You are required to know each of these categories.

4. Functional classification
Synarthroses – joints that have NO movement.
Examples: sutures of the skull, gomphoses- teeth
Amphiarthroses – partially movable joints.
Examples: intervertebral disc and pubic symphysis
Diarthroses – freely movable joints.
The most common type of functional joint in the body.
Examples: knee joint, shoulder joint, finger joints, ankle and wrist joints, etc.

5. Structural Classification
Fibrous joints (synarthroses): adjacent bones are joined by collagen fibers. 3 kinds:
- sutures, gomphoses and syndesmoses.
Cartilaginous joints (amphiarthroses): two bones are joined by cartilage. 2 kinds:
- synchondroses, and symphyses.
Synovial joints (Diarthroses): freely movable and most common joint in the body.

6. Joint mobility comparison
Note that as mobility decreases, stability increases.

7. Fibrous joints (synarthroses):

8. Cartilaginous joints (amphiarthroses)

9. Synovial Joints (diarthroses)
this type of joint is defined by the presence of a joint cavity filled with fluid.
Most joints of the body fall into this class.
Examples: knee joint, elbow joint, shoulder and hip joints and the phalanges of hands and feet, etc.

10. Structures in a Synovial Joint
articular capsule – external and internal
joint/synovial cavity – filled with synovial fluid
articular cartilage – Hyaline cartilage
synovial fluid – viscous/ clear colorless fluid
ligaments – give the joint reinforcement and strength
Nerves – provide feelings of pain and stretch
7. Vessels - provide nutrients to joint

11. Typical Synovial Joint

12. Hip Joint

13. Additional joint structures
Ligaments- join bones to bones
Consists of dense regular connective tissue.
Tendons- join muscles to bone
Bursae- fibrous sac lined with synovial membrane and containing synovial fluid
Occurs between bones and tendons or muscles
Acts to decrease friction during movement

14. Accessory joint structures
fatty pads - cushioning
menisci – tough fibrocartilage
bursae -flattened fibrous sac lined by synovial membrane.
tendon sheaths -fibrous tissue connecting a muscle to a bone

15. Knee joint structures Articular capsule Synovial membrane
Medial and lateral menisci
Suprapatellar, infrapatellar and prepatellar bursae
Anterior and posterior cruciate ligaments
Tibial and fibular collateral ligaments
Patellar capsule
Articular cartilage
Tendon of quadriceps femoris

16. Knee Joint Anterior view

17. Knee Joint posterior view

19. Types of Synovial Joints
Plane (gliding) Joints
Hinge Joints
Pivot Joints
Condyloid Joints
Saddle Joints
Ball and Socket Joints

21. Movements allowed by Synovial Joints
1. gliding – - bony surfaces of bone slide or glide over each other
2. flexion –- bending movement that decreases the angle
3. extension – movement the increases the angle, opposite of lexion
4. abduction –moving away from longitudinal axis
5. adduction –movement toward the longitudinal axis
6. circumduction –movement of the limb such that it describes a cone
7. rotation – turning the bone or limb around its long axis
8. supination –rotating the forearm laterally such that the palm faces superiorly

22. Movements allowed by Synovial Joints
9. pronation –- rotating the forearm medially such that the palm faces inferiorly
10. inversion –- sole of the foot faces or turns medially
11. eversion –- sole of the foot turn laterally
12. protraction –-juttting out of the jaw
13. retraction –- moving the jaw backward
14. elevation –- lifting the limb or body superiorly
15. depression –- moving the body part inferiorly
16. opposition –- to bring the thumb and index finger tips together

23. Body movements

24. Extension and flexion

25. Abduction and adduction

26. Protraction/Retraction Pronation/Supination
Opposition of thumb and pinky

27. Elevation/ Depression
Inversion/Eversion

28. Circumduction