Joints articulations

9-2
Articulations
 A joint, or articulation, is the place of contact
between bones, between bone and cartilage,
or between bones and teeth.

9-3
Naming of Joints
 Usually derived from the names of the
articulating bones.

9-4
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

9-6
Classification of Joints
 Type of connective tissue that binds the articulating
surfaces of the bones.
 Whether a space occurs between the articulating
bones.

9-7
Structural
 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

9-8
 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.

9-10
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

Sutures
 Joints of skull bone
 Fixed
 Affected by sutural ligaments
 Sites of active bone growth
 Process of obliteration of sutures is
called synostosis.
9-11

Gomphosis
(peg & socket joints)
 Fibrous joints in which teeth fit into
there sockets.
 Periodontal ligament connects the tooth
with socket or alveolus.
9-12

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)
9-13

9-14
Syndesmosis
 Fibrous joints in which articulating bones are
joined by ligaments only.

 Allow for slight movement.
 classified as amphiarthroses

9-15
Cartilaginous Joints
 Bones are attached to each other by cartilage.
 Lack a joint cavity.
 Two types.
 synchondroses
 symphyses

symphyses are amphiarthroses

18
Insert Fig. 9.4 Synovial Joints

9-20
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

9-21
General Anatomy of Synovial
Joints
 Basic features:
 articular capsule
 joint cavity
 synovial fluid
 articular cartilage
 ligaments
 nerves
 blood vessels

9-22
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 stabilize joints

9-27
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

9-28
Types of Synovial Joints
 From least movable to most freely movable, the six
specific types of synovial joints are:
 planar (gliding) joints
 hinge joints
 pivot joints
 condyloid (ellipsoid) joints
 saddle joints
 ball-and-socket joints

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

9-29

MOVEMENTS OF THE SYNOVIAL
JOINTS
 FREQUENCY THESE MOVEMENTS ARE COMBINED IN
A COMPLEX MANNER IN ORDER TO SHOW AN
INFINITE VARIETY.ONE KIND OF MOVEMENT IS NOT
FOUND IN ANY PARTICULAR JOINT.
 WHERE THE MOVEMENTS ARE LIMITED, THE
RECIPROCAL ARTICULAR SURFACES ARE
APPROXIMATELY OF EQUAL SIZE, BUT WHERE THE
MOVEMENTS ARE FREE, THE MORE MOVEABLE
BONE USUALLY POSSESSES THE LARGER
ARTICULAR SURFACE, AND e.g., THE HEAD OF THE
HUMERUS IS EXTREMELY LARGE AS COMPARED
WITH THE GLENOID CAVITY OF THE SCAPULA BONE.
9-30

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
9-31

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
9-32

A) FLEXION
 IT OCCURS ALONG A TRANSVERSE OR OBLIQUELY
TRANSVERSE AXIS. IT USUALLY RESULTS IN
APPROXIMATION OF TWO MORPHOLOGICALLY VENTRAL
SURFACES. THree FOLLOWING EXCEPTIONS:
 1.CARPOMETACARPAL JOINT THE THUMB:
HERE THE AXIS OF MOVEMENTS IS ANTERO-POSTERIOR
AND NOT TRANSVERSE.
 2.HIP JOINTS
HERE THE APPROXIMATION OF MORPHOLOGICALLY
DORSAL SURFACE OF THE THIGH AND VENTRAL
SURFACE OF THE TRUNK, TAKES PLACE DURING
FLEXION. THIS REVERSAL IS DUE TO ROTATION OF
LOWER LIMB DURING DEVELOPMENT.
9-33

B)EXTENSION
C) ADDUCTION
D) ABDUCTION
 B)EXTENSION:IT ALSO OCCURS ALONG A TRANSVERSE
AXIS AND IS CHARACTERIZED BY APPROXIMATION OF
TWO MORPHOLOGICALLY DORSAL SURFACES. THE
EXCEPTIONS ARE THE SAME AS IN FLEXION.
 C)ADDUCTOIN:IT OCCURS AROUND AN ANTERO-
POSTERIOR AXIS. IT IMPLIES THE APPROXIMATION
TOWARDS THE MEDIAN PLANE OF THE BODY. THE
EXCEPTION TO THIS DEFINITIONS IS CARPOMETA
CARPAL JOINT OF THE THUMB WHERE THE AXIS OF
MOVEMENT IS TRANSVERSE INSTEAD OF
ANTEROPOSTERIOR
 D)ABDUCTION:IT ALSO OCCURS ALONG THE
ANTEROPOSTERIOR AXIS. IT IS CHARACTERIZED BY DE-
APPROXIMATION (i.e., AWAY FROM) THE MEDIAN PLANE,
THE EXCEPTION IS THE SAME AS IN ADDUCTION.
9-34

III.ROTATAION OR ROTATORY
MOVEMENTS:
 THIS TERM IS OFTEN USED TO DENOTE A FORM OF
MOVEMENT IN WHICH A BONE MOVES AROUND SOME
LONGITUDINAL AXIS. THE AXIS OF THE ROTATION MAY LIE IN:
 A SEPARATE BONE, E.G., THE PIVOT OF DENS(2ND CERVICAL
VERTEBRA), AROUND WHICH THE ARCH OF ATLAS (IST CERVICAL
VERTEBRA) MOVES. OR
 THE SAME BONE, E.G., DURING THE ROTATION OF HUMERUS AT
THE SHOULDER JOINT, THE AXIS OF MOVEMENTS LIE IN THE
HUMERUS. OR
 TWO BONES OBLIQUE AXIS E.G., IN SUPERIOR RADIOULNAR JOINT
THE AXIS OF MOVEMENTS PASSES FROM RADIUS TO ULNA.
 THE BEST EXAMPLES OF ROTATORY MOVEMENTS ARE:
 SUPINATION AND PRONATION OF THE FOREARM, (IT OCCURS AT
THE SUPERIOR RADIOULNAR JOINT).
 INVERSION AND EVERSION OF THE FOOT. (IT OCCURS AT THE9-35

IV.CIRCUMDUCTION
 IT IS DERIVED MOVEMENT IN WHICH THE
ELEMENTS OF FLEXION, EXTENSION,
ADDUCTION AND ABDUCTION ARE
COMPOUNDED.THIS MOVEMENT
OCCURS AT THE FOLLOWING JOINTS:
 1.SHOULDER JOINT.
 2.HIP JOINT.
 3.CARPOMETACARPAL JOINT OF THE
THUMB.
9-37

V. MISCELLANEOUS MOVEMENTS :
THE AXIAL LINE OF THE HAND IS PASSING THROUGH THE MIDDLE
FINGER AND THE AXIAL LINE OF THE FOOT IS PASSING
THROUGH THE SECOND TOE.
 THE MOVEMENTS OF ADDUCTION AND ABDUCTION OF THE
FINGERS AND TOES ARE ACTUALLY THE MOMENTS TOWARDS
AND AWAY FROM THESE AXIAL LINES, I.E., MIDDLE FINGER AND
SECOND TOE.
 PRONATION MEANS A ROTATORY MOVEMENT IN WHICH THE
PALM OF THE HAND FACES BACKWARDS.
 SUPINATION MEANS A ROTATORY MOVEMENT IN WHICH
THE PALM OF THE HAND FACES FORWARDS.
9-38

V. MISCELLANEOUS MOVEMENTS
 INVERSION MEANS THE ROTATORY MOVEMENT OF THE FOOT IN
WHICH THE SOLE FACES INWARDS.
 EVERSION MEANS THE ROTATORY MOVEMENT OF THE FOOT IN
WHICH THE SOLE FACES OUT WARDS.
 OPPOSITION. IN THIS MOVEMENT THE PALMAR SURFACES OF
FINGERS ARE BROUGHT IN CONTACT WITH THE PALMAR SURFACE OF
FINGERS ARE BROUGHT IN CONTACT WITH THE PALMAR SURFACE OF
THE THUMB. IT IS THE CHARACTERISTIC MOVEMENT OF THE THUMB
OF THE HAND AND FORMS INTEGRAL PART OF GRASPING HOLDING
AND MANY OTHER SKILLED MOVEMENTS.
 PROTRACTION MEANS TO MOVE FORWARD, e.g., MOVEMENTS OF
LOWER JAW AND SHOULDER GIRDLE.
 RETRACTION MEANS TO MOVE BACKWARDS. EXAMPLES ARE THE
SAME AS OF PROTRACTION.
 ACCESSORY MOVEMENTS:
9-39

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)
45

• THE SYNOVIAL VESSELS PARTICULARLY SUPPLY THE
PERIPHERAL PORTION OF ARTICULAR CARTILAGE; WHERE
AS THE NUTRITION TO THE CENTRAL PART OF THE
CARTILAGE IS NOT SO ESTABLISHED. THUS IN OSTEO-
ARTHRITIS, THE PERIPHERAL PORTION MAY SHOW
OVERGROWTH, WHICH PRODUCES LIPPING OF ARTICULAR
MARGIN IN RADIOGRAPHS OF THE JOINTS, WHEREAS THE
CENTRAL PORTION SHOWS DEGENERATIVE CHANGES OF
VARYING DEGREE.
• THE RELATIVELY SMOOTH, FREE SURFACE OF THE
ARTICULAR CARTILAGE IS COMPRESSIBLE. THIS PROPERTY
DECREASES THE OCCURANCE OF UNPLEASANT SHOCKS AT
JOINTS. IF WE EXAMINE THE ARTICULAR CARTILAGE WITH
MICROSCOPE THE SMOOTH APPEARANCE IS NOT VISIBLE.
HOWEVER, ITS SURFACE SHOWS SLIGHT IRREGULARITIES
INDICATING NORMAL WEAR AND TEAR PROCESS.
• THE SYNOVIAL FLUID IS RELEASED INTO THE JOINT CAVITY
DURING MOVEMENTS AND IS REABSORBED BY THE
CARTILAGE WHEN MOVEMENT CEASES.
46

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.
49

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. THE SIZE AND SHAPE
OF THE TUBE VARIES WITH THAT OF ARTICULATING BONES.
DURING FOETAL LIFE THE CAPSULE IS ATTACHED TO THE
EIPHYSEAL CARTILAGE, WHICH IS REPRESENTED BY AN
EPIPHYSEAL LINE IN AN ADULT INDIVIDUAL. DURING
DEVELOPMENT THE ATTACHMENTS OF CAPSULE UNDERGO
MIGRATION. AS A RESULT OF THIS MIGRATION THE
EPIPHYSEAL LINE MAY BECOME COMPLETELY OR PARTLY
INTRA CAPSULE OR EXTRA CAPSULAR,
51

ARTICULAR CAPSULE
• 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.
• 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.
52

CAPSULAR LIGAMENTS:
• IN THE REGION OF CONSTANT STRESS AND STAIN, THE COLLAGEN
FIBRES OF THE CAPSULE ARE ARRANGED PARALLEL TO THE LINE
OF STRESS AND STRAIN, AND FORM CAPSULAR LIGAMENTS.
EXAMPLES:
• RADIAL COLLATERAL LIGAMENT OF ELBOW JOINT.
• ULNAR COLLATERAL LIGAMENT OF ELBOW JOINT.
• GLENOHUMERAL LIGAMENTS OF SHOULDER JOINT.
• ILIOFEMORAL LIGAMENT OF HIP JOINT.
• PUBOFEMORAL LIGAMENT OF HIP JOINT.
• ISCHIOFEMORAL LIGAMENT OF HIP JOINT.
• FUNCTIONS OF JOINT CAPSULE:
– IT UNITES THE ARTICULAR ENDS OF PARTICIPATING BONES.
– ITS FLEXIBLE NATURE ALLOWS MOVEMENTS.
– DUE TO GREAT TENSILE STRENGTH IT RESISTS DISLOCATIONS.
54

ACCESSORY LIGAMENTS
• THE ARTICULATING BONY ENDS ARE USUALLY CONNECTED BY A VARI-ABLE
NUMBER OF LIGAMENTS, WHICH ARE ADDITIONAL TO ARTICULAR CAPSULE,
AND CAPSULAR LIGAMENTS. THIS MAY BE:-
• EXTRA-CAPSULAR ACCESSORY LIGAMENTS: THIS TYPE IS MORE COMMON,
e.g.,
– CORACOCLAVICULAR LIGAMENT: IT IS AN ACCESSORY LIGAMENT OF
ACROMIOCLAVICULAR JOINT WHICH IS MAINLY RESPONSIBLE FOR
PERFECT CONNECTION AND STRENGTH OF JOINT INDEPENDENT OF
ARTICULAR CAPSULE.
– COSTOCLAVICULAR LIGAMENT: IT IS AN ACCESSORY LIGAMENT OF
STERNO-CLAVICULAR JOINT AND HELPS IN STRENGTHENING THE JOINT
ON ITS INFERIOR SURFACE.
– CORACOHUMERAL LIGAMENT OF SHOULDER, WHICH STRENGTHENS
THE SUPERIOR PART OF THE ARTICULAR CAPSULE.
– SACROTUBEROUS LIGAMENT.
– SACROPINOUS LIGAMENT. (ACCESSORY LIGAMENTS OF SACROILIAC
JOINTS)
55

INTRA CAPSULAR ACCESSORY LIGAMENTS
• THEY ARE LESS COM-MON BUT RELATIVELY MORE
IMPORTANT AS COMPARED WITH EXTRACAPSULAR
LIGAMENTS, e.g.,
– CRUCIATE LIGAMENTS OF KNEE JOINT: THEY STABALIZE
THE JOINT.
– LIGAMENT OF HEAD OF FEMUR: IT IS THE ACCESSORY
LIGAMENT OF THE HIP JOINT. IT HELPS INNUTRITION OF
HEAD OF FEMUR IN ADULTS.
56

SYNOVIAL MEMBRANE:
• IT IS A SMOOTH, PINKISH, SHINY, HIGHLY VASCULAR
MESENCHYMAL MEMBRANE WHICH LINES THE
ARTICULAR CAPSULE AND OTHER INTRA-ARTICULAR
STRUCTURES EXCEPT THE ARTICULAR CARTILAGES
AND ARTICULAR DICS/MENISCI.
• THE SYNOVIAL MEMBRANE IS THROWN INTO SYNOVIAL
VILLI, FOLDS AND FRINGES, WHICH ARE PROJECTING
INTO THE JOINT CAVITY. FATTY PADS ARE ALSO
RELATED WITH SYNOVIAL MEMBRANES OF MANY
JOINTS. EGG-ALBUMIN LIKE FLUID IS SEEN IN ALL
SYNOVIAL JOINTS, WHICH IS SECRETED BY THE
SYNOVIAL MEMBRANE.
• THE SYNOVIAL VILLI, FOLDS AND FRINGES ALONG
WITH FATTY PADS SERVE FOLLOWING FUNCTIONS:- 57

• THEY FORM FLEXIBLE CUSHIONS, WHICH FILL THE IT
PERFORMS THREE FUNCTIONS:
• IT TAKES PART IN THE PRODUCTION OF SYNOVIAL FLUID.
• IT HELPS IN ABSORPTION OF THE FLUID
• IT SHOWS PHAYGOCYTIC ACTIVITY.
• IRREGULARITIES IN JOINT CAVITY.
• FUNCTIONS OF THE SYNOVIAL MEMBRANE
• THEY FACILITATE JOINT MOVEMENTS.
• THEY INCREASE THE SURFACE AREA OF SYNOVIAL
MEMBRANE.
• THEY HELP IN ACHIEVEMENT OF EFFECTIVE LUBRICATION OF
JOINT.
• THE SYNOVIAL VILLI INCREASE WITH AGE AND BECOME
PROMINENT IN VARIOUS DISEASES OF JOINTS. 58

SYNOVIAL MEMBRANE STRUCTURE
LAMINA INTIMA
• IT IS COMPOSED OF 1-4 LAYERS OF SURFACE SYNOVIAL
CELLS, WHICH ARE IRREGULAR IN SHAPE (MAY BE
POLYHEDRAL OR FLATTENED). THESE CELLS FORM A
DISCONTINUOUS LAYER WITH GAPS OF 0.1-1.0 µ M.
THESE GAPS ARE FULL OF AMORPHOUS SUBSTANCE AND
FEW COLLAGEN FIBERS.
• AT THE GAPS THE JOINTS CAVITY IS SEPARATED FROM
BLOOD PLASMA BY ENDOTHELIUM AND AMORPHOUS
MATERIAL ONLY. THIS NATURE OF BLOOD-SYNOVIAL
BARRIER IS RESPONSIBLE FOR ABSORPTION OF LOW
MOLECULAR WEIGHT SUBSTANCES FROM THE JOINT
CAVITY. HOWEVER, THE COLLOIDAL SUBSTANCES ARE
REMOVED BY LYMPHATICS.
59

FUNCTIONS OF SURFACE CELLS
• THEY SECRETE SYNOVIAL MUCIN (HYALURONIC ACID).
• THEY CLEAR THE JOINT CAVITY FROM DEBRIS BY
PHAGOCYTIC POWER.
• ELECTRON MICROSCOPY REVEALS FOLLOWING TWO TYPES
OF CELLS LINING THE SYNOVIAL MEMBRANE:-
60

TYPE-A SYNOVIAL CELLS
• THEY SHOW FOLLOWING FEATURES :
• SURFACE FEET LIKE PROJECTIONS OF THE CELL MEMBRANE.
• INVAGINATIONS OF THE CELL MEMBRANE.
• PRESENCE OF MICROPINOCYTOTIC VESICLES NEAR THE INVAGI-
NATIONS.
• LYSOSOMES.
• A LARGE NUMBER OF MITOCHONDRIA.
• CYTOPLASMIC FILAMENTS.
• PROMINENT GOLGI COMPLEX (INDICATES SECRETORY ACTIVITY).
• VERY LITTLE GRANULAR ENDOPLASMIC RETICULUM.
61

FUNCTIONS OF TYPE-A SYNOVIAL CELLS
• THEY SECRETE HYALURONIC ACID.
• THEY SHOW PHAGOCYTIC ACTIVITY.
• THEY PRODUCE MACROPHAGES, WHICH MOVE INTO THE
SUBINTIMAL TISSUES AFTER PHAGOCYTOSIS OF UNWANTING
MATERIAL.
2) TYPE-B SYNOVIAL CELLS:
• THEY ARE CHARACTERIZED BY LARGE QUANTITY OF
GRANULAR ENDOPLASMIC RETICULUM AND SCANTY GOLGI
COMPLEXES. THEIR NUMBER IS VERY SMALL. THEIR FUNCTION IS
UNCERTAIN. THEY MIGHT BE SECRETING SOME TYPE OF PROTEIN-
MATERIAL WHICH IS BOUND TO HYALURONIC ACID (i.e.,
HYALURONATE-BOUND PROTEIN)
62

SYNOVIAL SUBINTIMAL TISSUE
• IT IS CHARACTERIZED BY FOLLOWING FEATURES:
• THERE IS A VARIABLE QUANTITY OF COLLAGEN, AND ELASTIN
FIBRES THE ELASTIN FIBRES ARE MORE IN MOST MOBILE PARTS OF
SYNOVIAL MEMBRANE.
• FAT CELLS ARE SEEN IN AGGREGATES AT CERTAIN PLACES TO
FORM FATTY PADS.
• MAST CELLS ARE SEEN IN LARGE QUANTITY.
• BLOOD VESSELS AND LYMPHATICS ARE PRESENT IN ABUNDANCE.
• FUNCTIONS OF SUBINTIMAL TISSUE:
• DUE TO HIGH ELASTICITY OF ELASTIN FIBRES AND THEIR
CONCENTRATION IN MOBILE PARTS OF THE SYNOVIAL MEMBRANE,
THE SUBINTIMAL TISSUE PREVENTS THE NIPPING OF SYNOVIAL
MEMBRANE DURING MOVEMENTS.
63

SYNOVIAL FLUID
• IT IS AN EGG-ABLUMEN LIKE FLUID PRESENT IN THE JOINT CAVITIES
OF SYNOVIAL JOINTS.BURSAE AND TENDON SHEATHS.
PROPERTIES:
• IT COMES FROM PLASMA WITH ADDITION OF HYALURONIC ACID.IT
SHOWS FOLLOWING PROPERTIES:-
• IT IS SLIGHTLY YELLOW, VISCOUS, CLEAR FLUID.
• IT IS SLIGHTLY ALKALINE IN PH, HOWEVER THE PH CHANGES WITH
ACTIVITY ,IN EXERCISE IT TURNS TOWARDS ACIDIC SIDE.
• ITS VOLUME IS VERY SMALL, e.g., 0.5ML FLUID CAN BE ASPIRATED
FROM THE KNEE JOINT.
CONTENTS
– HYALURONIC ACID OR SYNOVIAL MUCIN (SECRETED BY TYPE-A
CELLS)
– SOME PROTEINS (SECRETED BT TYPE-B CELLS).
64

THE CELL POPULATION COMPRISED
MONOCYTES,MACROPHAGES,LYMPHOCYTES.NEUTROPHILS
AND SYNOVIAL CELLS.
• ATMORPHOUS METACHROMATIC MATERIAL WHICH IS FORMED AS A
RESULT OF WEAR AND TEAR PROCESS
FUNCTIONS:
• IT PROVIDES NUTRITION TO THE ARTICULAR CARTILAGES, DISCS
AND MENISCI.
• IT LUBRICATES THE JOINTS AND IN THIS MANNER INCREASES THEIR
EFFICIENCY.
• IT PREVENTS THE EROSION OF ARTICULAR CARTILAGE DURING
MOVEMENTS AND WEIGHT BEARING.
• IT EXHIBITS PHAGOCYTIC ACTIVITY DUE TO IS CELLULAR
COMPONENTS.
65

ARTICULAR DISCS/MENISCI
• THESE ARE PADS OF WHITE-FIBROCARTILAGE INTERPOSED
BETWEEN THE TWO ARTICULAR BONY SURFACES.
• EXAMPLES:
• TEMPOROMANDIBULAR JOINT
• KNEE JOINT.
• STERNOCLAVICULAR JOINT.
• ACROMIOCLAVICULAR JOINT.
• RADIO ULNAR JOINT(i.e, INFERIOR RADIO ULNAR JOINT)
66

• FEATURES:
• THEY ARE COMPOSED OF DENSE FIBROUS TISSUE WITH FEW
CARTILAGE CELLS.
• AT THE PERIPHERY THEY ARE CONTINUOUS WITH THE ARTICULAR
CAPSULE THROUGH THE MEDIUM OF LOOSELY ARRANGED
VASCULAR CONNECTIVE TISSUE..
• THEY ARE ANERVOUS.
• THEY ARE AVASCULAREXCEPT AT THE PERIPHERY.
• THEY PARTLY OR COMPLETELY DIVIDE THE JOINT CAVITY INTO
PROXIMAL AND DISAL COMPARTMENTS(e.g., KNEE AND
TEMPOROMANDIBULAR JOINT RESPECTIVELY)
• ON THE PROXIMAL SURFACE OF THE DICS ONE TYPE OF
MOVEMENT TAKES PLACE(E.G., FLEXION AND EXTENSION) WHILE
ON THE DISTAL SURFACE ANOTHER TYPE OF MOVEMENT OCCURS
(e.g., ROTATION OR GLIDING)
67

• FUNCTOINS:
• THEY HELP IN LUBRICATION OF JOINTS.
• THEY INCREASE THE RANGE OF MOBILITY BY CONVERTING THE
SINGLE JOINT CAVITY INTO TWO, e.g.,
– TEMPOROMANDIBULAR JOINT.
– STERNOCLAVICULAR JOINT.
– INFERIOR RADIO-ULNAR JOINT.
– THEY ACT AS SHOCK ABSORBERS. ACTUALLY THE CARTILAGE IS
NON-WEIGHT BEARING SO IT CANNOT ACT AS SHOCK
ABSORBER (i.e., BUFFER ACTION)
– THEY STRENGTHEN THE JOINT BY ACTING LIKE AN ACCESSORY
LIGAMENT.
68

FATTY PADS(HAVERSIAN GLANDS)
• THESE ARE PADS OF FATTY TISSUE OCCUPYING SPACES WHERE
THE ARTICULAR SURFACES ARE UNEVEN.THEY ARE USUALLY
SITUATED BETWEEN:
– SYNOVAIL MEMBRANE AND FIBROUS CAPSULE.
– SYNOVIAL MEMBRANE AND BONE.
• EXAMPLES:
• HIP JOINT (HAVERSIAN PAD)
• KNEE JOINT(i.e., ALAR AND INFRA PATE FOLDS PATELLAR
FOLDS)
• TALO-CALCANEO NAVICULAR JOINT(MID-TARSAL JOINT).
• FUNCTIONS:
• THEY ACT LIKE SWABS TO SPREAD THE SYNOVIAL FLUID.
69

INTRA ARTICULAR STRUCTURES
• THESE ARE THOSE JOINT ELEMENTS, WHICH ARE SEEN INSIDE THE
ARTICULAR CAPSULE AND TAKE PART IN JOINT-STABILITY. THEY
INCLUDE THE FOLLOWING:-
• A) FATTY PADS:
• EXAMPLES:
• HIP JOINT.
• KNEE JOINT
• B) ARTICULAR DICS/MENISCI:
• EXAMPLES:
• LONG HEAD BICEPS BRANCHII AT THE SHOULDER JOINT.
• TENDON OF POPLITIEUS AT THE KNEE JOINT.
70

• D) LIGAMENTS
• EXAMPLES:
• LIGAMENTUM TERES OF THE HIP JOINT.
• CRUCIATE LIGAMENTS OF THE KNEE JOINT
• .INTRA-ARTICULAR LIGAMENTS OF HEADS OF 2ND
TO 9TH
RIBS. THESE
LIGAMENTS ARE ABSENT IN JOINTS OF HEAD OF THE FIRST, TENTH,
ELEVENTH AND TWELFTH RIBS.
• INTRAARTICULAR LIGAMENT OF 2ND
CHONDROSTERNAL JOINT
(STERNOCOSTAL JOINT).
• E) FIBROCARTILAGENOUS RIMS OF LABRA:
• EXAMPLES:
• THE GLENOIDAL LABRUM OF SHOULDER HIP JOINT.
• ACETABULAR LABRUM OF THE HIP JOINT.
• THEY HELP TO DEEPEN THE JOINT CAVITY.
71

9-87
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
PAKISTAN.
 gouty arthritis
 osteoarthritis

rheumatoid arthritis

Joints articulations

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

En vedette

En vedette (20)

Similaire à Joints articulations

Similaire à Joints articulations (20)

Plus de KemUnited

Plus de KemUnited (20)

Dernier

Dernier (20)

Joints articulations