Chapter 9
Joints
I. Classification of Joints (p. 205, Table 9.1)
A. Joints (articulations) are sites where two or more bones meet; joints give the human skeleton mobility and hold
it together.
B. Joints are classified by either structure or function.
1. Functional classification focuses on the amount of movement allowed at the joint. There are three functional
classifications for joints; synarthroses (immovable joints), amphiarthroses (slightly movable joints), and
diarthroses (freely movable joints).
2. Structural classification is based upon the material binding the joint together and the presence or absence of
a joint cavity. There are three structural classifications for joints; fibrous joints, cartilaginous joints, and
synovial joints.
II. Fibrous Joints (pp. 205–206, Fig. 9.1, Table 9.2)
A. Fibrous joints are connected by dense regular connective tissue and lack a joint cavity.
1. Sutures (immovable and located between skull bones)
2. Syndesmoses (connected exclusively by ligaments and amount of movement varies from no movement to
slightly or freely movable, depending on length of ligaments)
3. Gomphoses (a peg-in-socket joint for tooth attachment)
III. Cartilaginous Joints (pp. 206–207, Fig. 9.2, Table 9.2)
A. Bones are united by cartilage in cartilaginous joints and a joint cavity is lacking.
1. Synchondroses (united by hyaline cartilage and immovable)
2. Symphyses (united by fibrocartilage and slightly movable)
IV. Synovial Joints (pp. 207–230, Figs. 9.3–9.17, Table 9.2)
A. Synovial joints are characterized by a fluid-filled joint cavity; all synovial joints are freely movable
(diarthrotic) and most of the body’s joints are in this class.
B. All synovial joints have general structural characteristics in common.
1. Articular cartilage
2. Joint cavity (synovial cavity)
3. Articular capsule
4. Synovial fluid
5. Reinforcing ligaments
6. Nerves and vessels
C. Certain synovial joints contain menisci (articular discs).
D. Functioning of synovial joints is possible because friction is reduced in the joint by a mechanism called
weeping lubrication. (p. 209)
E. Several factors influence the stability of synovial joints: shapes of the articulating surfaces, ligaments, and tone
of muscles whose tendons cross the joint. (pp. 209–211)
F. Bursae and tendon sheaths are bags of lubricant (synovial fluid) that reduce friction between adjacent structures
associated with synovial joints. (p. 209, Fig. 9.4)
G. Movements allowed by synovial joints are three basic types. (pp. 211–213, Fig. 9.5, Table 9.3)
1. Gliding of one bone across another bone
2. Angular movements (flexion, extension, abduction, adduction, and circumduction)
3. Rotation of a bone around its long axis
H. Special movements of the body do not fit the basic categories. (pp. 213–216, Fig. 9.6, and Table 9.4)
1. Supination and pronation of the forearm
2. Dorsiflexion and plantar flexion of the foot
3. Inversion and eversion of the foot
4. Protraction and retraction of the mandible and scapula
5. Elevation and depression of the mandible and scapula
6. Opposition of the thumb
I. Shapes of the articulating bone surfaces determine the movements allowed at the joint. (pp. 216–217, Fig. 9.7)
1. Plane (translational)
2. Hinge or pivot (uniaxial)
3. Condyloid or saddle (biaxial)
4. Ball and socket (multiaxial)
J. Selected synovial joints. Each of the selected joints contain all structures common to synovial joints. (pp. 218–
230, Figs. 9.8–9.17)
1. Shoulder (glenohumeral) joint—the most moveable joint of the body; formed between the head of the
humerus and the glenoid cavity of the scapula. (Fig. 9.8)
2. Elbow joint—a hinge joint, which is stabilized by the articulation of the trochlear notch of the ulna and the
trochlea of the humerus. (Fig 9.9)
3. Wrist joint—has two major joint surfaces; the radiocarpal joint and the intercarpal joint. (Fig. 9.10)
4. Hip joint—a true ball-and-socket joint. Movement is possible in all axes, but limited by the deep articular
surface ligaments. (Fig. 9.11)
5. Knee joint—the most complex joint; acts primarily as a hinge. (Figs. 9.12–9.14)
6. Ankle joint—a single hinge between the inferior ends of the tibia and fibula and the talus of the foot. (Fig.
9.15)
7. Temporomandibular joint—a diarthrotic joint; the condyle of the mandible articulates with the mandibular
fossa of the temporal bone. (Fig. 9.16)
8. Sternoclavicular joint—a saddle joint formed between the manubrium of the sternum and the medial end of
the clavicle. This joint’s unique shape allows for multiple complex movements. (Fig. 9.17)
V. Disorders of Joints (pp. 230–233, Fig. 9.18)
A. There are three basic types of joint injuries: sprains, dislocations, and torn cartilage.
B. Examples of joint inflammatory and degenerative conditions are bursitis, tendinitis, many types of arthritis
(including osteoarthritis, rheumatoid arthritis, and gout), and Lyme disease.
VI. The Joints Throughout Life (p. 233)
A. Joints are derived from embryonic mesenchyme between the cartilaginous “bone models” in the late embryo.
B. Osteoarthritis is the most common joint problem associated with advancing age.
SUPPLEMENTAL STUDENT MATERIALS to Human Anatomy,
Fifth Edition
Chapter 9: Joints
To the Student
Now that you know the names of the bones of the skeleton, it is time to explore the union of bones and how movement
of the skeleton is accomplished. Chapter 9 introduces you to the variety of joints (articulations) that form where bone
attaches to bone. Although most joints unite bone to bone, some articulations join bone to cartilage. Relate the structure
of the joint to the specific type of joint and the degree of mobility permitted. A specific movement is determined by the
structure of the joint. When a muscle contracts, movement occurs. Study movements carefully and thoroughly so that
your next step, the study of muscles in Chapter 10, will not be difficult to master.
Step 1: Be able to classify joints.
- Define joint (articulation).
- Classify joints according to structure.
- Classify joints according to function.
Step 2: Describe and understand fibrous joints.
- Describe the general structure of fibrous joints.
- Give examples of three types of fibrous joints.
- Describe the mobility of each type of fibrous joint.
- Point out examples of fibrous joints on a diagram of a skeleton.
Step 3: Describe and understand cartilaginous joints.
- Describe the general structure of cartilaginous joints.
- Name two examples of cartilaginous joints.
- Describe the mobility of each type of cartilaginous joint.
- Point out examples of cartilaginous joints on a skeletal diagram.
Step 4: Describe and understand synovial joints.
- List basic structural characteristics of a synovial joint.
- Explain the mobility of a synovial joint.
- Explain how synovial joints function, including weeping lubrication.
- Distinguish between bursae and tendon sheaths and explain their significance within a synovial joint.
- Name and explain three factors that influence joint stability.
- Distinguish between gliding, angular, and rotation types of movements.
- Give examples of gliding joints.
- Define and give examples of five types of angular movements: flexion and extension, abduction and adduction,
and circumduction. Include the plane of movement for each action.
- Define and give examples of rotation.
- Define and give examples of the following special movements: supination and pronation, dorsiflexion and plantar
flexion, inversion and eversion, protraction and retraction, elevation and depression, and opposition.
- List and give examples of six structural types of synovial joints.
- Distinguish among nonaxial, uniaxial, biaxial, and multiaxial joints.
- For each of the following selected synovial joints, name the articulating bones, the structural type of joint, the
functional type of joint, and all movements permitted.
• Temporomandibular joint
• Shoulder joint
• Elbow joint
• Hip joint
• Ankle joint
Step 5: Fill in the following joint classification work sheet.
Apply three of the following terms to each of the joints on the numbered list.
Amphiarthrosis
Diarthrosis
Synarthrosis
Ball and socket
Condyloid
Gliding
Hinge
Pivot
Saddle
Suture
Symphysis
Synchondrosis
Syndesmosis
Gomphosis
Fibrous joint
Cartilaginous joint
Synovial joint
1. Interlocking joint between cranial bones:
___________________________________________________________________________
2. Knee joint:
____________________________________________________________________________________________
_______________
3. Elbow joint:
____________________________________________________________________________________________
______________
4. Intervertebral joint between articular processes:
___________________________________________________________________
5. Articulation between tibia and fibula at distal ends:
________________________________________________________________
6. Shoulder joint:
____________________________________________________________________________________________
___________
7. Symphysis pubis:
____________________________________________________________________________________________
________
8. Joint between the diaphysis and epiphysis of a long bone of a child:
______________________________________________
9. Joint between the first metacarpal and carpus (trapezium):
________________________________________________________
10. Wrist (carpals to carpals):
___________________________________________________________________________________________
11. Ankle (tarsals to tarsals):
____________________________________________________________________________________________
12. Ankle (talus to tibia):
____________________________________________________________________________________________
_____
13. Hip joint:
____________________________________________________________________________________________
_________________
14. Axis-atlas rotation:
____________________________________________________________________________________________
______
15. Finger joint (between phalanges):
___________________________________________________________________________________
16. Phalanges to metacarpals:
___________________________________________________________________________________________
17. Toe joint (between phalanges):
______________________________________________________________________________________
18. Phalanges to metatarsals:
___________________________________________________________________________________________
19. Teeth and mandible or maxilla:
_____________________________________________________________________________________