Joints (1).ppt

The Skeletal System
Articulations

Joints (Arthroses)
• Articulations, are connections between bones
that may or may not permit movement
- cartilage, fluid, or dense CT are usually involved in
holding joints together
• Joints are classified functionally by the amount of
movement they allow
- immovable or slightly movable joints tend to be in the
axial skeleton
- freely movable joints are more common in the
appendicular skeleton

Table 8.1 Functional Classification of Articulations
Functional
Category
Structural
Category
Description Example
Synarthrosis:
no movement
Fibrous:
Suture
Gomphosis
Cartilaginous:
Synchondrosis
Bony Fusion:
Synostosis
Fibrous Connections
+ extensive interlocking
+ insertion in alveolar
process
Interposition of cartilage
plate
Conversion of other
articular form to a solid
mass of bone
Between skull bones
Periodontal ligaments
Epiphyseal cartilages
Portions of the skull,
ie along the frontal
suture; epiphyseal
lines

Table 8.1 Functional Classification of Articulations
Functional
Category
Structural
Category
Description Example
Amphiarthrosis:
little movement
Fibrous:
Syndesmosis
Cartilaginous:
Symphysis
Ligamentous connection
Connection by a pad of
fibrous cartilage
Between the tibia and
fibula
Pubic symphsis; be-
tween adjacent
vertebral bodies
Diarthrosis:
free movement
Synovial
Monaxial
Biaxial
Triaxial
Complex joint bounded
by joint capsule and
containing synovial fluid
Permits:
Movement in 1 plane
Movement in 2 planes
Movement in all 3 planes
Numerous; subdivided
by range of movement
(fig 8.3 to 8.6)
Elbow, ankle
Ribs, wrist
Shoulder, hip

Synarthroses (Immovable Joints)
Syn ‘together’ + arthros ‘joint’ – bony edges are close and
may interlock
• Sutures (sutura ‘sewing together’) are joints
found only in the skull
- bony edges interlock and short dense CT fiber (sutural
ligament or sutural membrane) holds the bones together
• Gomphosis (‘a bolting together) - joint between a
tooth & alveolar fossa of the maxillae or mandible
- periodontal ligaments hold the tooth to the bone
• Synchondrosis - joint in which hyaline cartilage
separates the ends of the bones involved
• Synostosis – rigid immovable joint
- occurs if bones fuse together to form one bone

Permit very limited movement, bones are usually
further apart than at a synarthrosis
• Syndesmosis (desmo ‘band or ligament’) - bones
are connected by relatively long CT ligaments that
limits movement of the articulating bones
- distal articulation between the tibia and fibula
- interosseous membrane between the radius and ulna
• Symphysis – bones are separated by a wedge or
pad of fibrous cartilage
- the intervertebral disc and the pubic symphysis
Amphiarthroses
(Slightly Movable Joints)

Synovial joints – permit a wide range of motion
• Typically found at the ends of long bones in the
upper and lower limbs
• All synovial joints have 6 basic characteristics:
- A joint capsule
- Articular cartilages – act as shock absorbers
- A joint cavity filled with synovial fluid
- A synovial membrane lining the joint capsule
- Accessory structures
- Sensory nerves and blood vessels
Diarthroses (Freely Movable Joints)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 8.1a

Synovial Fluid
• Synovial joints are surrounded by a joint (articular)
capsule composed of a thick layer of dense CT
- a synovial membrane lines the cavity (but stops at the
edges of the articular cartilages), produces the synovial fluid
Synovial fluid has 3 functions:
• Lubricates the surfaces of the articular cartilages on the ends
of the bones – hyaluronan & lubricin
• Nourishes the chondrocytes by entering and exiting the
articular cartilages due to the forces acting on the joint (joint
movement)
• Acts as a shock absorber – presure increases the synovial
fluid absorbs and distributes the shock

Accessory Structures
• Cartilages and Fat Pads – lie between opposing
articular surfaces
- Menisci (sing. meniscus ‘crescent’) or articular discs:
pads of fibrous cartilage that channel the flow of synovial
fluid (allow for surface variations or restrict joint
movements)
- Fat pads found around the joint periphery (covered by a
layer of synovial membrane) provide protection and serve
as packing material for the joint (fill spaces when bones
move changing the cavity shape)

Structure of a Synovial Joint
Fig 8.1b

• Ligaments – intrinsic (capsular) or extrinsic
- the joint capsule is continuous with the periostea of the
articulating bones and the accessory ligaments support,
strengthen, and reinforce synovial joints
- intrinsic are localized thickenings of the joint capsule
- extrinsic are separate from the joint capsule, may be
located outside (extracapsular ligament) or inside
(intracapsular ligament) the joint capsule
• Tendons – typically not part of the articulation
- usually pass across or around a joint
- may limit the range of motion
- normal muscle tone keeps these tendons taut
- in some joints may be an integral part of the joint capsule
to provide strength

• Bursae – small, fluid-filled pockets in CT
- filled with synovial fluid and lined by a synovial membrane
- may be connected to the joint cavity or completely separate
from it
- form where a tendon or ligament rubs against other tissues
- function to reduce friction and as a shock absorber
- found around most synovial joints, such as the shoulder
joint
• Synovial tendon sheaths – tubular bursae that
surround tendons
- where they pass across bony surfaces or beneath the skin
covering a bone or within other CTs exposed to friction
- adventitious bursae, develop in abnormal locations or due
to abnormal stresses

Strength versus Mobility
• Joints cannot be both highly mobile and very strong
- greater range of movement; weaker the joint becomes
- synarthrosis, strongest joint allows no movement
- mobile diarthrosis may be damaged by movement beyond
its normal capacity
• Factors that combine to limit mobility (reduce
chance of injury)
- presence of accessory ligaments and collagen fibers of the
joint capsule
- articulating surface shapes prevent movement in specific
directions
- presence of other bones, bony processes, skeletal
muscles, or fat pads around the joint; and
- tension in tendons attached to the articulating bones

Articular Form and Function
Types of movement:
• Linear movements – forward or backward or
diagonally
• Angular movements – changes the angle
between the shaft and the articular surface
• Rotation – prevent movement of the base and
keep the shaft vertical, the shaft can spin
around its longitudinal axis
• Special movements

1: gliding
2: abduction (ab, from) and adduction (ad, to); flexion and extension
3: left/right, internal/medial, external/lateral rotations; pronation and supination
A Simple Model of Articular Motion
Fig 8.2a

Special Movements
• Movements at the ankle include:
- Eversion/inversion
- Dorsiflexion/plantar (tiptoes) flexion
• Movement of the vertebral column – lateral flexion
• Movement of the pollex (thumb)
- Opposition/reposition

Special movements that occur at many joints include:
• Protraction – movement anteriorly in the horizontal
plane
• Retraction – movement posteriorly in the horizontal
plane
• Elevation – movement cranially in the vertical axis
• Depression – movement caudally in the vertical
axis

Figure 8.3a,c

Figure 8.3b,d

Copyright © 2009 Pearson Education, Inc., publishing as Pearson
Benjamin Cummings
Figure 8.4

Structural Classification of
Synovial Joints
• Plane joints – nonaxial and multiaxial
• Hinge joints – flexion and extension
• Pivot joints – rotational movements
• Condylar joints – flexion/extension and
abduction/adduction
• Saddle joints – biaxial that also allow
circumduction
• Ball and socket joints – triaxial joints

Fig 8.6a
• Aka planar have flattened or slightly curved faces
- flat articular surfaces slide across one another, slight movement
- ends of the clavicles, between carpal and tarsal bones, between
articular facets of adjacent vertebrae
- may be nonaxial (permit only small sliding movements) or multiaxial
(permit sliding in any direction)

Fig 8.6b
• Permit angular movement in a single plane
- like the opening and closing of a door
- monaxial such as the elbow and knee

Fig 8.6c
• Are monaxial but permit only rotation
- between the atlas and axis allows rotation of the head to either side

Fig 8.6d
• Aka condylar joint – oval articular face rests within a
depression on the opposing surface
- angular motion occurs in 2 planes, along or across the length of the oval
- a biaxial joint: connection between fingers and toes with their metacarpal
and metatarsal bones

Fig 8.6e
• Have complex articular faces – resembles a saddle
- concave on one axis and convex on the other
- extremely mobile, allows extensive angular motion without rotation
- usually classifed as biaxial: movement at the base of the thumb

Fig 8.6f
• The round head of one bone rests within a cup-shaped
depression in another
- all combinations of movements, including rotation
- triaxial joints: shoulder and hip joints

The Temporomandibular Joint (Lateral View)
Fig 8.7

The Temporomandibular Joint (Sectional View)
Fig 8.7

Intervertebral Articulations
Fig 8.8

Damage to the Intervertebral Discs
Fig 8.9a

Damage to the Intervertebral Discs
Fig 8.9b

The Sternoclavicular Joint
Fig 8.10

The Glenohumeral Joint (Anterior View)
Fig 8.11a

The Glenohumeral Joint (Lateral View of Pectoral Girdle)
Fig 8.11b

The Glenohumeral Joint (Anterior View, Frontal Sec)
Fig 8.11c

Figure 8.11d The Glenohumeral Joint (Superior View, Horizontal Section)

Fig 8.12a The Elbow Joint (Lateral View)

Fig 8.12b The Elbow Joint (Medial View)

The Elbow Joint (X-ray, Sagittal View, and Articular Surfaces)
Fig 8.12

The Radioulnar Joints
Fig 8.13

The Joints of the Wrist and Hand
Fig 8.14a,b

The Joints of the Wrist and Hand
Fig 8.14c

Figure 8.14d The Joints of the Wrist and Hand

Figure 8.15 The Hip Joint (Lateral View)

Figure 8.15 The Hip Joint (Anterior View)

Figure 8.15 The Hip Joint (Posterior View)

Figure 8.16 Articular Structure of the Hip Joint (Sectional View)

Figure 8.16 Articular Structure of the Hip Joint (X-ray)

Figure 8.16 Articular Structure of the Hip Joint (Coronal Section)

Fig 8.7
The Knee Joint, Part II

Figure 8.17 The Knee Joint, Part I (X-ray, Partially Flexed Knee)

Figure 8.17 The Knee Joint, Part I (MRI of Right Knee Joint)

Figure 8.18 The Knee Joint, Part II (Posterior View, Deep Layer)

Figure 8.18 The Knee Joint, Part II (Anterior Views, Flexed Knee)

Figure 8.19 An Arthroscopic View of the Interior of an Injured Knee,
Showing a Damaged Meniscus

Figure 8.20a The Joints of the Ankle and Foot, Part I

Figure 8.20b The Joints of the Ankle and Foot, Part I

Figure 8.21a The Joints of the Ankle and Foot, Part II (Superior Views)

Figure 8.21c The Joints of the Ankle and Foot, Part II (Lateral View)

Figure 8.21 The Joints of the Ankle and Foot, Part II (Posterior View of
Coronal Section)

Figure 8.21 The Joints of the Ankle and Foot, Part II (Medial Views)

 Skeletal and muscular systems are
structurally and functionally interdependent
 Considered to be part of a single
musculoskeletal system

Aging and Articulations
• Rheumatism – pain and stiffness affecting the
skeletal system, the muscular system, or both
• Arthritis – includes all rheumatic diseases that
affect synovial joints
• Both conditions are common among older
individuals

Joints (1).ppt

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Joints (1).ppt

Similar to Joints (1).ppt (20)

More from kenosewe1

More from kenosewe1 (14)

Recently uploaded

Recently uploaded (20)

Joints (1).ppt