Articulations

Define the term joint

Articulations, points where bones meet

Identify the function of a joint

Permits Movement

Identify the three functional classes of joints

Synorthroses

Amphiarthrosis

Diarthrosis

Describe the type of movement produced by each of the three functional classes of joints

Synorthroses (immovable joint)

Amphiarthrosis (slightly moveable joint)

Diarthrosis (freely movable joint)

Identify/describe the following types of synarthrotic joints: Suture, Periodental, synchondrosis, synostosis

Suture- a fibrous joint found only between the bones of the skull whose edges are interlocked and bound together by dense connective tissue

Periodental- ligament - a fibrous synarthrotic joint that binds each tooth to the surrounding bony socket, the articulationis a gomphosis

Synchondrosis- a cartilaginous synarthrotic joint such as the articulation between the epiphysis and diaphysis of a growing bone

Synostosis- a bony fusion that creates a totally rigid, immoveable object

Identify/describe the following types of amphiarthrotic joints: symphysis, syndesmosis

Syndesmosis- a fibrous amphiarthrosis (bones are connected by a ligament)

Symphysis- a cartilaginous amphiarthrosis; bones are separated by a wedge or pad of fibrou cartilage (EX: pubic symphysis)

Identify/describe the following types of diarthrosis joints:

ball-and-socket, hinge, saddle, ellipsoidal, gliding, pivot

1. Ball-and socket joint is round head of one bone rests within a cup-shaped depression, Are triaxial, all combinations of movements including rotation can be preformed

2. Hinge joint permits angular movement in a single plane and is a monaxial joint

3. Saddle joint have complex articular surfaces- concave on one axis and convex on the other, are extremely mobile allowing extensive angular motion without rotation, are biaxial

4. Ellipsoidal joints are an oval articular face nestles witnin a depression on the opposing surface, a biaxial joint

5. Gliding joints have flatened orslightly curved faces that slide across one another, but the amount of movement is slight

6. Pivot joints permit only rotation and are monaxial joints

Identify the functions of synovial fluid at a joint

provides lubrication that reduces friction between moving surfaces in a joint

Nourishes the chondrocytes

acts as a shock absorber distributing the shack evenly across the articular surfaces

Describe the role of accessory structures at a joint:

Cartilage, fat pads, tendons, ligaments, bursae

Cartilage - Meniscior articular discs that may subdivide a synovial cavity, channel the shape of the articular surfaces

Fat pads- found at the edges of the joint where they protect the articular cartilages and provide packing spaces produced as the joint cavity changes

Ligaments- Accessory ligaments are localized thickenings of the capsule, Extracapsular ligaments are located outside of the capsule, Intracapsular ligaments are located inside the capsule

Tendons- Not part of the joint itself, they pass around or across a joint limiting the range of motion and providing mechanical support

Bursae- A small, synovial fluid-filled pocket in connective tissue, Form where a tendon or ligament rubs against the tissues to reduce friction and act as a shock absorber

A joint cannot both be strong and highly mobile

The greater the range of motion at a joint, the weaker it becomes

Define luxation

Occurs when the articulating surfaces are forced out of position which can damage the articular cartilages, terriligaments, or dissort the joint capsule [Dislocation]

Define Subluxation

A partial Dislocation

Define monaxial, biaxial, and triaxial

1. Monaxial articulation permit movement along only 1 axis (Ex:only forward/back movement at a joint)

2. Biaxial articulations provide movement along 2 axes (Ex: right/left movement, but not simultaneously)

3. Triaxial/Multiavial articulations provides movement in multiple axes; most mobile joint

Identify the following movements produced by diatheric joints: flexion-extension, Hyper extension, Rotation, inverse-eversion, Opposition, Elevation-depression, Abduction-adduction, Circumdunction, Pronation-supination, Dorsiflexion plantar flexion, Protraction-retraction

flexion-extension Flection is movement in the anterior/post here you're playing that reduces the angle between the articulating elements

Extension is movement in the interior/posterior plane that increases the angle between articulating elements Extension is movement in the interior/posterior plane that increases the angle between articulating elements

Hyper extension, Hyperextension is extension that occurs past the amatomical position, usually prevented by ligaments, bony processes, or soft tissue

Rotation internal rotation is toward the ventural body surface

External or lateral rotation away from the ventral body surface

inverse-eversion Inversion is a twisting motion of the foot that turns the sole inward

Eversion is a twisting motion of the foot that turns the soul outward

Opposition Special movement of the thumb that enables it to grasp and hold an object (reverse movement is reposistion)

Elevation-depression Elevation is movement of a structure in a superior direction

Depression is movement of a structure in an inferior direction

Abduction-adduction Abduction is movement away from belonging to junior access of the body in the frontal plane

Adduction is movement toward the longitudinal access of the body in the frontal plane

Circumdunction Movement in a complete circular motion

Pronation-supination Pronation is movement of the hand and wrist from a Palm facing front to Palm facing back

Supernation is movement of the hand and wrist from a Palm facing back to a Palm facing front

Dorsiflexion-plantar flexion Dorsiflexion is a flexion of the ankle and elevation of the soul digging in heels

Plantar flexion is a extension of the ankle and elevation of the heel standing on tiptoes

Protraction-retraction Protraction is moving apart of the body anterially in the horizontal plane

Retraction is moving apart of the body posterily in the horizontal plane

Identify examples of the following types of joints: ball-and-socket, hinge, saddle, ellipsoidal, gliding, pivot

1. Ball-and-socket; shoulder joint (glenohumeral joint) and Hip joint (coval joint)

2. Hinge; Elbow Knee

3. Saddle; Base of the thumb

4. Ellipsoidal; connections between fingers and metacarpals and connections between the toes and metatarsals

5. Gliding; Ends of the clavicle, between the carpals, between the tarsals, between the articular facetsaf adjacent spinal vertebrae

6. Pivot; Joints between the atlas and the axis