This document provides an overview of the classification and structure of different joint types in the body. It discusses the three main classifications of joints based on movement (synarthroses, amphiarthroses, diarthroses) and structure (fibrous, cartilaginous, synovial). It then describes the key characteristics and examples of different joint types, including fibrous joints like sutures and syndesmoses, cartilaginous joints like synchondroses and sympheses, and synovial joints. For synovial joints, it outlines the general structure including articular cartilage, joint cavity, articular capsule, synovial fluid, ligaments, and more. It also discusses

1. Joints
Dr. Mohamed Shawa

2. Classification of Joints
 Functional classification
(Focuses on amount of movement)
 Synarthroses (immovable joints)
 Amphiarthroses (slightly movable joints)
 Diarthroses (freely movable joints)
 Structural classification
(Based on the material binding them and presence or
absence of a joint cavity)
 Bony fusion
 Fibrous
 Cartilagenous
 Synovial

3. Table of Joint Types
Functional across
Structural down
Synarthroses
(immovable joints)
Amphiarthroses
(some movement)
Diarthroses
(freely movable)
Bony Fusion Synostosis
(frontal=metopic
suture; epiphyseal
lines)
Fibrous Suture (skull only)
-fibrous tissue is
continuous with
periosteum
Gomphoses (teeth)
-ligament is
periodontal ligament
Syndesmoses
-ligaments only
between bones; here,
short so some but not
a lot of movement
(example: tib-fib
ligament)
Syndesmoses
-ligament longer
(example: radioulnar
interosseous
membrane)
Cartilagenous
(bone united by
cartilage only)
Synchondroses
-hyaline cartilage
(examples:
manubrium-C1,
epiphyseal plates)
Sympheses
-fibrocartilage
(examples: between
discs, pubic
symphesis
Synovial Are all diarthrotic

4. Fibrous joints
 Bones connected by fibrous tissue: dense
regular connective tissue
 No joint cavity
 Slightly immovable or
not at all
 Types
 Sutures
 Syndesmoses
 Gomphoses

5. Sutures
 Only between
bones of skull
 Fibrous tissue
continuous with
periosteum
 Ossify and fuse in
middle age: now
technically called
“synostoses”=
bony junctions

6. Syndesmoses
 In Greek:
“ligament”
 Bones connected
by ligaments only
 Amount of
movement
depends on length
of the fibers: longer
than in sutures

7. Gomphoses
 Is a “peg-in-socket”
 Only example is
tooth with its
socket
 Ligament is a short
periodontal
ligament

8. Cartilagenous joints
 Articulating bones united by cartilage
 Lack a joint cavity
 Not highly movable
 Two types
 Synchondroses (singular: synchondrosis)
 Sympheses (singular: symphesis)

9. Synchondroses
 Literally: “junction of cartilage”
 Hyaline cartilage unites the bones
 Immovable (synarthroses)
 Examples:
 Epiphyseal plates
 Joint between first rib’s costal cartilage and
manubrium of the sternum

10. Sympheses
 Literally “growing together”
 Fibrocartilage unites the bones
 Slightly movable (amphiarthroses)
 Resilient shock absorber
 Provide strength and flexibility
 Hyaline cartilage on articular surfaces of bones
to reduce friction
 Examples
 Intervertebral discs
 Pubic symphysis of the pelvis

11. Synchondroses and sympheses
Also pubic symphsis

12. Synovial joints
 Include most of the body’s joints
 All are diarthroses (freely movable)
 All contain fluid-filled joint cavity

13. General Structure of Synovial Joints
1. Articular cartilage
 Hyaline
 Spongy cushions absorb
compression
 Protects ends of bones
from being crushed
2. Joint (synovial) cavity
 Potential space
 Small amount of synovial
fluid

14. General structure of synovial joints (cont.)
3. Articular (or joint) capsule
 Two layered
 Outer*: fibrous capsule of
dense irregular connective
tissue continuous with
periosteum
 Inner*: synovial membrane
of loose connective tissue
(makes synovial fluid)
 Lines all internal joint
surfaces not covered by
cartilage*
*
*
*

15. General structure of synovial joints (cont.)
4. Synovial fluid
 Filtrate of blood
 Contains special glycoproteins
 Nourishes cartilage and
functions as slippery lubricant
 “Weeping” lubricatioin
5. Reinforcing ligaments (some
joints)
 Capsular (most) – thickened
parts of capsule
 Extracapsular
 Intracapsular

16. General structure of synovial joints (cont.)
6. Nerves
 Detect pain
 Monitor stretch (one of the
ways of sensing posture
and body movements)
7. Blood vessels
 Rich blood supply
 Extensive capillary beds in
synovial membrane
(produce the blood filtrate)

17. General structure of synovial joints

18.  Articular disc or
meniscus
(literally “crescent”)
 Only some joints
 Those with bone
ends of different
shapes or fitting poorly
 Some to allow two kinds of movement (e.g. jaw)
 Of fibrocartilage
 Examples: knee
TMJ (temporomandibular joint)
sternoclavicular joint
Some joints…

19. Bursae and tendon sheaths
 Contain synovial fluid
 Not joints but often associated with them
 Act like ball bearings
 Bursa means “purse” in Latin
 Flattened sac lined by synovial membrane
 Where ligaments, muscles, tendons, or bones
overlie each other and rub together
 Tendon sheath
 Only on tendons subjected to friction

20. Bursae and tendon sheaths

21. Joint stability
 Articular surfaces
 Shape usually plays only minor role
 Some deep sockets or grooves do provide stability
 Ligaments
 Usually the more, the stronger the joint
 Can stretch only 6% beyond normal length before
tear
 Once stretched, stay stretched
 Muscle tone
 Constant, low level of contractile force
 Keeps tension on the ligaments
 Especially important at shoulders, knees, arches of
foot

22. Movements allowed by synovial joints
 Gliding
 Angular movements: or  the angle between
two bones DO TOGETHER
 Flexion
 Extension
 Abduction
 Adduction
 Circumduction
 Rotation
 Special movements

23. Special movements
 Pronation
 Supination
 Dorsiflexion
 Plantar flexion
 Inversion
 Eversion
 Protraction
 Retraction
 Elevation
 Depression
 Opposition

24. Joint movements pics
(from Marieb, 4th
ed.)

30. Synovial joints
classified by shape
(of their articular surfaces)
 Plane (see right)
 Hinge (see right)
 Pivot
 Condyloid
 Saddle
 Ball-and-socket

32. Shoulder
(glenohumeral) joint
 Stability sacrificed for
mobility
 Ball and socket: head of
humerus with glenoid
cavity of scapula
 Glenoid labrum: rim of
fibrocartilage
 Thin, loose capsule
 Strongest ligament:
coracohumeral
 Muscle tendons help
stability
 Disorders
Selected synovial joints
Rotator cuff muscles add to stability
Biceps tendon is intra-articular

33. Elbow joint
 Hinge: allows only flexion
and extension
 Annular ligament of
radius attaches to
capsule
 Capsule thickens into:
 Radial collateral
ligament
 Ulnar collateral
ligament
 Muscles cross joint
 Trauma

34. Wrist joint
Two major joint surfaces
Several ligaments stabilize
1. Radiocarpal joint
 Between radius and
proximal carpals
(scaphoid and lunate)
 Condyloid joint
 Flexion extension
adduction, abduction,
circumduction
1. Intercarpal or
midcarpal joint
 Between the proximal
and distal rows of
carpals

35. Hip (coxal) joint
 Ball and socket
 Moves in all axes but
limited by ligaments
and deep socket
 Three ext. ligaments
“screw in” head of
femur when standing
 Iliofemoral
 Pubofemoral
 Ischiofemoral

36.  Acetabular labrum
diameter smaller than
head of femur
 Dislocations rare
 Ligament of head of
femur supplies artery
 Muscle tendons cross
joint
 Hip fractures common
in elderly because of
osteoporosis

37. Right hip, AP view

38. Knee joint
 Largest and most complex joint
 Primarily a hinge
 Compound and bicondyloid: femur and
tibia both have 2 condyles
 Femoropatellar joint shares joint cavity
 At least a dozen bursae
 Prepatellar
 Suprapatellar

39.  Lateral and medial
menisci
 “torn cartilage”
 Capsule absent
anteriorly
 Capsular and
extracapsular ligaments
 Taut when knee
extended to prevent
hyperextension

40.  Patellar ligament
 Continuation of
quad tendon
 Medial and lateral
retinacula
 Fibular and tibial
collateral ligaments
 Called medial and
lateral
 Extracapsular
 Oblique popliteal
 Arcuate popliteal

41. Cruciate ligaments
 Cross each other
(cruciate means cross)
 Anterior cruciate (ACL)
 Anterior intercondylar area
of tibia to medial side of
lateral condyl of femur
 Posterior cruciate
 Posterior intercondylar
area of tibia to lateral side
of medial condyl
 Restraining straps
 Lock the knee

42. Cruciate ligaments

43. Knee injuries
 Flat tibial surface
predisposes to
horizontal injuries
 Lateral blow: multiple
tears
 ACL injuries
 Stop and twist
 Commoner in women
athletes
 Heal poorly
 Require surgery

44. Ankle joint
 Hinge joint
 Distal tibia and fibula to talus
 Dorsiflexion and plantar
flexion only
 Medial deltoid ligament
 Lateral ligaments: 3 bands
 Anterior talofibular
 Posterior talofibular
 Calcaneofibular
 Anterior and posterior
tibiofibular (syndesmosis)

45. Right ankle, lateral view

48. Temporomandibular
joint (TMJ)
 Head of mandible
articulates with temporal
bone
 Disc protects thin
mandibular fossa of
temporal bone
 Many movements
Demonstrate movements together
 Disorders common

49. Sternoclavicular joint
 Saddle joint
 Only other example is trapezium
and metacarpal 1 (thumb),
allowing opposion
 Sternum and 1st
costal (rib)
cartilage articulate with clavicle
 Very stable: clavicle usually
breaks before dislocation of joint
 Only bony attachment of axial
skeleton to pectoral girdle
Demonstrate movements together

50. Disorders of joints
 Injuries
 Sprains
 Dislocatios
 Torn cartilage
 Inflammatory and degenerative conditions
 Bursitis
 Tendinitis
 Arthritis
 Osteoarthritis (“DJD” – degenerative joint disease)
 Rheumatoid arthritis (one of many “autoimmune” arthritites)
 Gout (crystal arthropathy)