Joints 9-1 Classification of Joints ▪ Synarthrosis 1

Home , Joint capsule, Plane joint

Lab 10: Joints 9-1 Classification of Joints ▪ Synarthrosis 1. Suture - Found only between bones of skull • Edges of bones interlock • Bound by dense fibrous connective tissue 2. Gomphosis - Binds teeth to bony sockets • Fibrous connection (periodontal ligament) 3. Synchondrosis - Rigid cartilaginous bridge between two bones • Found between vertebrosternal ribs and sternum • Also, epiphyseal cartilage of growing long bones 4. Synostosis - Created when two bones fuse • Example: metopic suture of frontal bone • And epiphyseal lines of mature long bones

2 9-1 Classification of Joints ▪ Amphiarthrosis • More movable than a synarthrosis • Stronger than a diarthrosis • May be fibrous or cartilaginous • Two types of amphiarthroses 1. Syndesmosis—bones connected by a ligament 2. Symphysis—bones connected by fibrocartilage

3 9-2 Synovial Joints ▪ Synovial joints (diarthroses) • Freely movable joints • At ends of long bones • Surrounded by joint capsule (articular capsule) • Contains synovial membrane • Synovial fluid from synovial membrane • Fills joint cavity • Articular cartilage covers articulating surfaces • Prevents direct contact between bones

4 Medullary cavity

Spongy bone Periosteum Components of Synovial Joints

Fibrous joint capsule Synovial membrane Articular cartilages Joint cavity (contains synovial fluid)

Ligament

Metaphysis

Compact bone

a Synovial joint, sagittal section 5 Quadriceps tendon

Patella Accessory Structures Joint capsule Femur of a Knee Joint Synovial Bursa membrane Joint cavity Fat pad Articular Meniscus cartilage Ligaments Tibia Extracapsular ligament (patellar) Intracapsular ligament (cruciate)

b Knee joint, sagittal section 6 9-3 Movements at Synovial Joints Axes of Motion ▪ Movements are described in terms that reflect the Movement of joints can also be described by the number of axes that they can rotate around. A joint • Plane or direction of that permits movement around one axis is called movement monaxial, a joint that permits movement around two axes is called biaxial, and one that permits • Relationship between movement around three axes, is called triaxial. structures Superior–inferior axis ▪ Planes of movement

• Monaxial—1 plane (e.g., Lateral–medial axis elbow) • Biaxial—2 planes (e.g., Anterior–posterior axis wrist) • Triaxial—3 planes (e.g., shoulder)

7 9-3 Movements at Synovial Joints ▪ Plane joint (gliding joint) • Flattened or slightly curved surfaces • Limited motion (nonaxial)

Plane joint Plane joints, or gliding Movement: Examples: joints, have flattened or Gliding. • Acromioclavicular and slightly curved surfaces Slight claviculosternal joints that slide across one nonaxial • Intercarpal joints another, but the amount of Manubrium • Vertebrocostal joints movement is very slight. • Sacro-iliac joints

▪ Hinge joint – Angular motion in a single plane (monaxial)

Hinge joint Hinge joints permit angular Movement: Humerus Examples: motion in a single plane, Angular. • Elbow joint like the opening and Monaxial • Knee joint closing of a door. Ulna • Ankle joint • Interphalangeal joint 8 9-3 Movements at Synovial Joints ▪ Condylar joint – Oval articular face within a depression – Motion in two planes (biaxial)

Condylar joint Movement: Examples: Condylar joints, or ellipsoid Angular. • Radiocarpal joint joints, have an oval articular face Biaxial Scaphoid • Metacarpophalangeal nestled within a depression on bone joints 2–5 the opposing surface. • Metatarsophalangeal Radius Ulna joints

▪ Saddle joint – Articular faces fit together like a rider in a saddle – Biaxial

Saddle joint

Saddle joints have complex Movement: Metacarpal Examples: articular faces and fit together Angular. III II bone of • First carpometacarpal like a rider in a saddle. Each Biaxial thumb joint face is concave along one axis and convex along the other. Trapezium 9 9-3 Movements at Synovial Joints ▪ Pivot joint • Rotation only • Monaxial

Pivot joint Movement: Examples: Rotation. • Atlanto-axial joint Pivot joints only Atlas Monaxial • Proximal radio-ulnar permit rotation. joint Axis

▪ Ball-and-socket joint – Round head in a cup-shaped depression – Triaxial

Ball-and-socket joint Movement: Examples: Angular, In a ball-and-socket • Shoulder joint circumduction, Scapula joint, the round head • Hip joint and rotation. of one bone rests within Triaxial a cup-shaped depression Humerus in another. 10 Figure 9–8a The Right Knee Joint.

Quadriceps tendon

Ligaments that Stabilize Patella the Knee Joint Patellar retinaculae Tibial collateral ligament

Fibular collateral Patellar ligament ligament

Fibula Tibia

a Anterior view, superficial layer 11 Figure 9–8b The Right Knee Joint.

Patellar surface Ligaments that Stabilize the Knee Joint

Posterior cruciate ligament Lateral Medial Anterior cruciate condyle condyle ligament

Tibial collateral ligament Menisci

Medial Fibular collateral ligament Tibia Cut tendon of Lateral biceps femoris muscle

Fibula

b Deep anterior view, flexed 12 Figure 9–8c The Right Knee Joint. Plantaris muscle Gastrocnemius Femur muscle, Gastrocnemius muscle, medial head lateral head

Ligaments that Stabilize the Knee Joint Bursa Tibial collateral Joint ligament capsule Fibular collateral ligament

Popliteal ligaments

Cut tendon of Popliteus biceps femoris muscle Tibia muscle

Fibula

c Posterior view, superficial layer 13 Figure 9–8d The Right Knee Joint.

Femur Ligaments that Stabilize the Knee Joint Anterior cruciate Fibular ligament collateral ligament Posterior cruciate ligament Medial Lateral Menisci condyle condyle Lateral

Medial

Cut tendon

Tibia Fibula

d Deep posterior view, extended 14 Figure 9–3a Angular Movements and Circumduction.

Extension

Flexion Hyperextension

Flexion

Flexion Hyper- extension

Extension Extension

Flexion Hyperextension

Extension a Flexion/extension 15 Figure 9–3b Angular Movements and Circumduction.

Abduction

Adduction Adduction

Abduction

Abduction Adduction

Adduction

b Abduction/adduction relative to the midline of the body 16 Figure 9–3c Angular Movements and Circumduction.

Adduction Abduction

c Adduction/abduction relative to central digit

17 Figure 9–4a Rotational Movements. Head rotation

Right Left rotation rotation

Atlanto-axial joint

Lateral (external) Medial rotation (internal) rotation

a Rotation 18 Figure 9–4b Rotational Movements.

Supination Pronation

b Supination/pronation

Supination Pronation 19 Figure 9–5a Special Movements.

a Eversion Inversion

20 Figure 9–5b Special Movements.

Dorsiflexion (flexion at ankle)

Plantar flexion (extension at ankle)

21 Figure 9–5c Special Movements.

– Opposition • Movement of thumb toward palm or other fingers – Reposition • Opposite of opposition

c Opposition – Protraction • Anterior movement in horizontal plane (forward) – Retraction • Opposite of protraction (pulling

back) d Retraction Protraction 22 9-3 Movements at Synovial Joints ▪ Special movements – Depression • Moving a structure inferiorly (down) – Elevation • Moving a structure superiorly (up)

– Lateral flexion • Bending vertebral column to the side

f Lateral flexion