Arthrology Limbs

Arthology Definition

Study of joints

2 ways that joints are classified according to

Structure and function

3 structural classification of joints

• Fibrous

• Cartilaginous

• Synovial

Fibrous Joints

Composed of fibrous tissue with no joint cavity

Example of Where Fibrous Joints are Found

Joints between skull bones

Cartilaginous Joints

Articulating bones are united by cartilage and no joint cavity present

Synovial Joints

Articular bones are separated by a fluid-filled joint cavity

Example of Synovial Joints

Knees, ankles, wrists, shoulders

3 Functional Classification of Joints

• Synarthroses

• Amphiarthroses

• Diarthroses

Synarthroses

Immovable joints

Amphiarthroses

Slightly movable joints (vertebral bodies and pubic bones)

Example of Amphiarthoses Joints

Vertebral bodies and pubic bones

Diarthroses

Freely movable joints

Example of Diarthroses Joints

Most appendicular joints

Pair Each Joint Structure with Joint Function

• Fibrous - Synarthroses

• Cartilaginous - Amphiarthroses

• Synovial - Diarthroses

Three Types of Fibrous Joints

• Sutures

• Syndesmoses

• Gomphoses

Sutures

Contain dense fibrous connective tissue until adulthood when they ossify (synostoses)

Examples of Sutures

Skull bones (plates)

Syndesmoses

• Bones are connected by a filamentous sheet or cord (ligament or interosseous membrane)

• Fibers are longer than in sutures but are only slightly more resilient

• Movement can range from slight to considerable

• Tibiofibular and the radioulnar joint

What connects bones in syndesmoses fibrous joints?

Filamentous sheet or cord (ligament or interosseous membrane)

How do fibers in syndesmoses compare to sutures?

Longer but only slightly more resilient

What is range of movement in syndesmoses fibrous joints?

Slight to considerable movement

What are examples of syndesmoses fibrous joints?

Tibiofibular and the radioulnar joint

Gomphoses

• Articulation of tooth with body alveolar surface

• Peg in socket

• Possess a fibrous connection called the periodontal ligament

What is the articulation of the tooth with the body alveolar surface?

Gomphoses

What fibrous connection is present in gomphoses?

Periodontal ligament

Two Types of Cartilaginous Joints

• Synchondroses

• Symophyses

Synchondroses

• Hyaline cartilage unites bones at a synchondrosis

• Cartilage is replaced by bone and becomes synarthrotic

• Epiphyseal plate and the costal cartilage of the first rib and the manubrium of the sternum

What type of cartilage is found in synchondroses?

Hyaline cartilage

What does hyaline cartilage do in synchondroses?

Unites bones at a synchondrosis

What happens to cartilage in synchondroses over time?

Cartilage is replaced by bone and becomes synarthrotic

Examples of Synchondroses

• Epiphyseal plate

• Costal cartilage of the first rib and the manubrium of the sternum

Symphyses

• Articular surface of bone covered by hyaline cartilage fused to an intervening pad or plate

• Compressible, resilient, and functionally amphiarthrotic

• Pubic symphysis and the intervertebral discs

What covers the articular surfaces of bone in symphyses?

Hyaline cartilage

What lies between/fused to the bones in a symphysis?

Intervening pad or plate

What are the mechanical properties of symphyses?

Compressible and resilient

What is the functional classification of symphyses?

Amphiarthrotic (slightly movable)

Examples of Symphyses

• Pubic symphysis

• Intervertebral discs

All synovial joints are __________. (Function)

Diarthrotic (opposing bones move freely)

Five Distinct Features of the Skeleton (Synovial Joints)

• Articular cartilage

• Joint cavity

• Synovial fluid

• Articular capsule

• Reinforcing ligaments

What is articular cartilage?

Hyaline type forms a glassy smooth surface over the opposing ends of bones

What is the joint cavity?

Small space between articulating bones in synovial joint filled with synovial fluid

Where does synovial fluid derive from?

Largely derived from blood

What is the consistency of synovial fluid?

Viscous, egg-white consistency

What is the function of synovial fluid?

Leaks out of the cartilage, provides “weeping” lubrication

What are the two parts of the articular capsule?

• Fibrous capsule (External)

• Synovial membrane (internal)

What is the function of reinforcing ligaments?

Support and strengthen the joint

What are the supportive structures of synovial joints?

Bursae

Bursae Description

Flattened sacs lined with a synovial membrane and contain a thin film of synovial fluid

Bursae Location

Where ligaments, muscles, and tendons overlie and rub against bone

Example of Synovial Joints with Pads of Fibrocartilage Between the Ends of Bones

Menisci of the knee

What is gliding joint motion?

Bones displaced in relation to one another

Examples of Joints with Gliding Motion

• Intercarpal

• Intervertebral

What is angular joint motion?

Changing the angle between two bones

Flexion vs. Extension (Joint Motion)

• Flexion: decreasing joint angle

• Extension: increasing joint angle

Dorsiflexion vs. Plantar Flexion (Joint Motion)

• Dorsiflexion: point toes towards you/up (flexing foot)

• Plantar Flexion: point towards away from you/down

Abduction vs. Adduction (Joint Motion)

• Abduction: moving away

• Adduction: moving towards

Circumduction vs. Rotation (Joint Motion)

• Circumduction: draw around in a circle

• Rotation: turning movement of a bone around its own axis (can be medial or lateral)

Supination vs. Pronation (Special Movements)

• Supination: turning backwards (radius/ulna)

  • Palms face forward

• Pronation: turning forwards (radius ulna)

  • Palms face backward

Inversion vs. Eversion (Special Movements)

• Inversion: movement of the food medially

  • Sole facing in

• Eversion: movement of the foot laterally

  • Sole facing out

Protraction vs. Retraction (Special Movements)

• Protraction: movement of the mandible (jawbone) forward

• Retraction: movement of the protracted part back to its starting position

Elevation vs. Depression (Special Movements)

• Elevation: lifting a body part superiorly (towards top)

• Depression: moving the elevated part inferiorly (towards bottom)

Oppostion (Special Movements)

Touching your thumb to the tips of other fingers

Six Types of Synovial Joints

• Plane Joints

• Hinge Joints

• Pivot Joints

• Condyloid Joints

• Saddle Joints

• Ball and socket

Plane Joints Description

Flat articular surface and only allow for short gliding movements

Example of Plane Joints

• Intercarpal Joints

• Intertarsal Joints

Hinge Joints Description

Cylindrical projection of one bone fits into a trough-shaped surface on another bone

Example of Hinge Joint

Elbow

Pivot Joint Description

Rounded end of one bone protrudes into a sleeve or ring composed of bone or ligament

Example of Pivot Joints

• Radius to ulna

• Axis to atlas

Condyloid Joints Description

Oval articular surface of one bone fits into a complementary depression in another

Example of Condyloid Joints

Metacarpophalanges: knuckles

Saddle Joints Description

Each articular surface has a concave and convex area

Example of Saddle Joint

Carpometacarpal joint of the thumb

Ball and Socket Joint

Spherical end of one bone articulates with a cuplike socket of another bone

Example of Ball and Socket Joint

Shoulder or hip joint