Joints

1. 1
Human Anatomy
Chondrology & Arthrology

2. 6-2
Cartilage Connective Tissue
Characteristics:
 Weaker than bone
 More flexible than bone
 Cells in an abundant matrix.
 Cell Types
 Chondroblasts
 Chondrocytes in lacunae
 Avascular

3. 6-3

4. 6-4
3 Major Functions of Cartilage
 Supporting soft tissues.
 Providing a gliding surface at
articulations (joints)
 Providing a model for the formation of
most of the bones in the body.

5. 6-5
Types of Cartilage
 Three types of cartilage:
 Hyaline cartilage

Most abundant kind

Has a perichondrium (membrane)

Associated with synovial joints

Most bones first modeled in hyaline cartilage
 Fibrocartilage

Has collagen fibers

Intervertebral discs, pubic symphysis
 Elastic cartilage

Has elastic fibers

Ear, respiratory tubing

6. 6-6

7. 9-7
Articulations
 A joint, or articulation, is the place of contact
between bones, between bone and cartilage,
or between bones and teeth.

8. 9-8
Naming of Joints
 Usually derived from the names of the
articulating bones.

9. 9-9
Mobility and Stability in Joints
 Motion permitted ranges from none to various
extensive motions.

Structure determines both its mobility and its stability.
 more mobile = less stable

10. 10

11. 9-11
Structural
Classification of Joints
 A fibrous joint occurs where bones are held together
by dense regular (fibrous) connective tissue.
 A cartilaginous joint occurs where bones are joined
by cartilage.
 A synovial joint
 has a fluid-filled synovial cavity
 bones are enclosed within a capsule
 bones are joined by various ligaments

12. 9-12
Classification of Joints
 Functionally based on the extent of movement they
permit:
 Synarthrosis is an immovable joint.
 Amphiarthrosis is a slightly movable joint.

Diarthrosis is a freely movable joint.

13. 9-13
Fibrous Joints
 Union is due to dense fibrous tissue.
 Most are immovable or only slightly
movable.
 Have no joint cavity.
 Three types.
 Gomphosis
 sutures
 syndesmosis

14. 14

15. Sutures
 Joints of skull bone
 Fixed
 Affected by sutural ligaments
 Sites of active bone growth
 Process of obliteration of sutures is
called synostosis.
9-15

16. Gomphosis
(peg & socket joints)
 Fibrous joints in which teeth fit into their
sockets.
 Periodontal ligament connects the tooth
with socket or alveolus.
9-16

17. Varieties of sutures.
 Depends on shape of articulating surfaces and mode
of fusion of articulating bones.
 Serrate sutures (sagittal suture).
 Denticulate suture (lambdoid suture).
 Squamous Plane sutures (temporo parietal suture).
 Limbus suture
 Plane sutures ( inter palantine suture).
 Wedge and groove suture(vomero sphenoid suture)
9-17

18. 9-18
Cartilaginous Joints
 Bones are attached to each other by cartilage.
 Lack a joint cavity.
 Two types.
 Primary cartilaginous joint or synchondrosis

Symphyses, secondary cartilaginous joints.

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20. 20

21. 9-21
Synovial Joints
 Freely movable articulations
 Classified as diarthroses
 Bones are separated by a space called a joint
cavity
 Most of the commonly known joints in the
body
 glenohumeral (shoulder) joint
 temporomandibular joint
 elbow joint
 knee joint

22. 22
Insert Fig. 9.4 Synovial Joints

23. 9-23
General Anatomy of Synovial
Joints
 Basic features:
 articular capsule
 joint cavity
 synovial fluid
 articular cartilage
 ligaments
 nerves
 blood vessels

24. 9-24
General Anatomy of Synovial
Joints – Accessory Structures
 Bursae
 fibrous, saclike structure that contains synovial fluid and is
lined by a synovial membrane
 Fatpads
 often distributed along the periphery of a synovial joint
 act as packing material and provide some protection for the
joint
 fill the spaces that form when bones move and the joint
cavity changes shape
 Tendons
 attaches a muscle to a bone
 help to stabilize joints

25. 25

26. STRUCTURES COMPRISING A
SYNOVIAL JOINT
• ARTICULAR BONY SURFACES:
• THE CONTIGUOUS BONY SURFACES, WHICH ARE TAKING
PART IN THE FORMATION OF A JOINT, ARE CALLED ARTICULAR
BONY SURFACES. THESE SURFACES ARE NOT IN CONTINUITY
WITH EACH OTHER BUT ARE RATHER WELL ADAPTED TO
EACH OTHER.
• EACH BONY ARTICULAR SURFACE IS COVERED BY BLUISH-
WHITE ARTICULAR-WHICH IS AVASCULAR, ANERVOUS AND
DEVOID OF PERICHONDRIUM.
• IT DERIVES ITS NUTRITION BY DIFFUSION FROM THREE
SOURCES:
• SYNOVIAL FLUID.
• EPIPHYSEAL VESSELS.
• SYNOVIAL VESSELS (CIRCULUS VASCULOSUS ARTICULI)
26

27. 27

28. JOINT CAVITY (SYNOVIAL CAVITY)
• EVERY SYNOVIAL JOINT HAS A
SPECIAL CAVITY LINED BY SYNOVIAL
MEMBRANE. THIS CAVITY IS NOT AN
EMPTY SPACE, BUT IS FILLED WITH A
LUBRICATING FLUID CALLED
SYNOVIAL FLUID.
28

29. ARTICULAR CAPSULE AND ITS
THICKENINGS (CAPSULAR LIGAMENTS)
• EACH JOINT IS SURROUNDED BY A TUBULAR DENSE
FIBROUS CAPSULE, WHICH IS ATTACHED TO THE ARTICULAR
LINES OF THE PARTICIPATING BONES.
• EXAMPLES
– EPIPHYSEAL LINE OF HEAD OF FEMUR IS COMPLETELY
INTRACAPSULAR.
– EPIPHYSEAL LINE OF LOWER END OF FEMUR IS
COMPLETELY EXTRA CAPSULAR.
– EPIPHYSEAL LINE OF UPPER END PARTLY EXTRA
CAPSULAR.
29

30. ARTICULAR CAPSULE
• THE FIBROUS CAPSULE OF THE JOINT MAY BE
STRENGTHENED BY ADJACENT MUSCLES, TENDONS AND
ACCESSORY LIGAMENTS OR TRUE LIGAMENTS.
• SMALL NERVES AND VESSELS ARE PIERCING THE CAPSULE.
THE SYNOVIAI MEMBRANE MAY PROTRUDE OUT OF THE
CAPSULE THROUGH HOLES AND FORM BURSAE, WHICH
REDUCE FRICTION DURING MOVEMENTS.
30

31. ARTICULAR CAPSULE EXAMPLE
31

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36. 9-36
Types of Synovial Joints
 Classified by the shapes of their articulating surfaces
 Types of movement they allow
 uniaxial if the bone moves in just one plane
 biaxial if the bone moves in two planes
 multiaxial (or triaxial) if the bone moves in multiple
planes

37. 9-37
Types of Synovial Joints
 From least movable to most freely movable, the six
specific types of synovial joints are:
 Plane (gliding) joints intercarpal joint.
 hinge joints Elbow joint.
 pivot joints ,atlanto axial ,proximal radio ulnar joint
 condyloid (ellipsoid) joints , knee
joint,metacarpophalangeal joint.
 saddle joints.ankle joint,carpometacarpal joint.
 ball-and-socket joints.shoulder joint ,hip joint.

38. 38

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41. 41

42. MOVEMENTS OF THE SYNOVIAL
JOINTS
 THE MOVEMENTS PERMITTED AT A JOINT (e.g.,
SYNOVIAL) ARE OF FOLLOWING TYPES:-
 GLIDING.
 ANGULAR.
 ROTATION.
 CIRCUMDUCTION.
 MISCELLANEOUS.
9-42

43. I.GLIDING MOVEMENTS
 IT IS THE SIMPLEST KIND OF MOVEMENTS IN
WHICH ONE SURFACE CRAWLS OVER THE
OTHER WITHOUT ANY ANGULAR OR ROTATORY
MOVEMENTS.
EXAMPLES:
 INTER CARPAL JOINTS
 INTER TARSAL JOINTS (ONLY GLIDING IS
POSSIBLE)
 MANY SYNOVIAL JOINTS
9-43

44. II.ANGULAR MOVEMENTS
 IT IMPLIES DECREASE OR INCREASE IN
ANGLE BETWEEN THE ADJOINING
BONES.
 THE ANGULAR MOVEMENTS ARE OF
FOUR TYPES:
 A) FLEXION
 B) EXTENSION
 C) ADDUCTION
 D) ABDUCTION
9-44

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62. 9-62
Arthritis
 A group of inflammatory or degenerative
diseases of joints that occur in various forms.
 swelling of the joint
 pain
 stiffness
 Most prevalent crippling disease in the United
States.
 gouty arthritis
 osteoarthritis

rheumatoid arthritis