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TRANSCRIPT
Buy your lab coat and gloves!
Chapter 9Joints = Articulations
Where ANY bones come together
Developed by John Gallagher, MS, DVM
Classification of Joints
1. Function 1. Based on ROM
2. Structure 1. Based on structure
and whether there is a joint cavity
1. Functional Classification of Joints
1) Synarthrosis (no movement) • Fibrous (Sutural or Gomphosis) • Cartilaginous (Synchondrosis often becomes
synostosis) • Bony Fusion (Synostosis) 2) Amphiarthrosis (little movement) • Fibrous (Syndesmosis – tibia to fibula) • Cartilaginous (Symphysis) 3) Diarthrosis (free movement)
Three types of movement Six Types of structure
2. Structural Classification of Joints (Marieb utilizes Structural Classification (See Table 9.1)
u 1. Fibrous (no joint cavity) u Almost no movement, little CT u E.g, Sutures in calvarium
u 2. Cartilaginous u E.g., Symphysis pubis, IV disks
u 3. Synovial – by far most important
1. Fibrous (no joint cavity)
u Sutures u Only in the skull
u Lambdoidal, Coronal, etc. u Minimal movement u Growth allowed
u Syndesmosis (pl. syndesmoses) u Ligamentous attachments u Minimal movement u E.g., distal tibia to distal fibula
u Gomphosis (pl. gomphoses) u Teeth u Periodontal ligament
2. Cartilaginous = Union by cartilage
u Synchondrosis u Hyaline cartilage u Epiphyseal plates u May become
synostosis u Symphysis
u Fibrocartilage u Intervertebral Disks,
symphysis pubis
3. Synovial (with egg white) – most important! p 209
1. Articular Cartilage 1. Hyaline
2. Joint Cavity or Space 3. Articular capsule
1. Synovial Membrane 2. Joint capsule
4. Synovial Fluid 1. Nourishes 2. Cushions 3. Lubricates
5. Reinforcing Ligaments 6. Nerves and blood
supply
3. Synovial, cont’d
u Depends on: u Shape of articular
surfaces u Supporting Ligaments u Muscle Tone
Joint Stability
Bursae and Tendon Sheaths
u Bags of synovial fluid u Lubrication and cushion
u Tendons u Ligaments
n.b.: Tendinitis, Synovitis
Three Types of Motion at Synovial Joints
u Linear motion = gliding
u Angular motion : u flexion, extension,
hyperextension u ab-, adduction
u Rotation u left - right, internal or medial,
external or lateral u C1 – C2 , leg/foot, radius
u Special Movements u Pronation, supination
Special Movements
u Supination, Pronation u Radius/ulna
u Dorsiflexion, plantar flexion u Elevation, depression u Eversion, Inversion
Table 9.4
6 types of Synovial Joints
1 Plane (Gliding) Joint 2 Hinge Joint 3 Pivot Joint 4 Condyloid (Ellipsoidal) Joint 5 Saddle joint 6 Ball & Socket joint
See (p 216, fig 9.8)
Representative Articulationsu Temporomandibular Joint
u Mostly hinge joint, some gliding and rotation
u Articular disc
Intervertebral articulations
u Gliding joints between vertebrae u Articular facets (synovial
joints u Intervertebral discs:
(Amphiarthroses) u annulus fibrosus: tough
outer layer (fibrocartilage) u nucleus pulposus: soft,
gelatinous core u Account for ~25% of
vertebral column height – H2O loss during aging
Glenohumeral (shoulder) Joint
Greatest range of motion (due to loose capsule and shallow glenoid)
u Most frequently dislocated
u Stability provided by rotator cuff (p 223)
Hip (coxofemoral joint)
u Deep well fitted ball and socket joint
u Stabilization: u Extracapsular and
intracapsular ligaments (ligamentum teres = ligamentum capitis femoris)
u Strong joint capsule u Extensive surrounding
musculature
Knee
u Much more complex than elbow
u Less stable than other hinge joints u Some gliding and rotation
u Structurally 3 separate joints
u No single joint capsule
More Knee
u Extra- and intracapsular structures u Medial and lateral
meniscus u Cruciate ligaments u Collateral ligaments
(extracapsular) u Fat Pads u Patella and Patellar
Tendon/ligament Anterior Posterior
Knee, sagittal section
Ant. Cruc. Lig.
The infamous ACL
u Twisting u Soccer, skiing, etc.
u 8X more common in women u Hormones u Strength u Geometry
u Surgery is optional u Several techniques
u Post-op period
Total Knee Replacement
Total Knee Replacement
The Ankle and Foot
u Hinge Joint u Deltoid and three Lateral
Ligaments u Calcaneous = Heel Bone
u Calcaneal/Achilles Tendon u Talus articulates with tibia u Intertarsal and
Tarsometatarsal Joints u Cunieform bones u Metarsal and phalangeal
bones u Similar to the hand