Inroduction Of Arthrology -ruan-2015.ppt

ARTHROLOGY

03-11-2015

DEFINITION •

Arthrology is the science that study joints.

•

Joints are places where two or more bones make contact.

Classification of articulation (joints) I. Based on Function 1. Synarthrosis –immovable joints 2. Amphiarthrosis –slightly movable joints

restricted to the axial skeleton.

3. Diarthrosis –freely movable joints - predominate in limbs.

II. Based on structures 1.

Fibrous joints

2.

Cartilaginous joints

3.

Synovial joints

1. Fibrous Joints (Synarthrosis) - bones are connected by collagen fibers (no joint

cavity) ① Sutures - a rigid joint between bones • serrate sutures • Lap sutures • Plane sutures

1. Fibrous Joints (Synarthrosis) ②Gomphoses ( 嵌合连接） • a joint that binds the teeth to dental alveoli (socket)in the maxillary and bone and mandible bones. • Held in place by fibrous periodontal ligament • Some movement while chewing

1. Fibrous Joints (Synarthrosis) ③Syndesmoses (韧带联合) • •

the bones are united by fibrous connective tissue forming an interosseous membrane or ligament. slightly movable articulation

2. Cartilaginous joints •Bones are joined by cartilages ① Synchondrosis (软骨结合) - Bones are joined by hyaline cartilage (透明软骨) •

ribs articulates with the sternum by costal cartilage

•

epiphyseal plate binds epiphysis and diaphysis

2. Cartilaginous joints ② Symphysis • two bones joined by fibrocartilage

– pubic symphysis – intervertebral discs • slight movement

3. Synovial joints (Diarthrosis,滑膜关节) • Most movable joints of the body

(1) Essential structures ①Articular surface

– formed by hyaline cartilage – covers joint surfaces – helps reduce friction and pressure.

3. Synovial joints (1) Essential structures ② Articular capsule – two layers encloses joint cavity • fibrous membrane - continuous with periosteum • synovial membrane – lines the internal surface of the fibraous menbrane – secretes synovial fluid that reduces friction, dissipate heat, and absorb shock. ③Articular cavity - a space in which two bones are separated

Synovial joints

3. Synovial joints (2) Accessory structures ①Ligaments- help hold the joint together. ② Articular discs and menisci - jaw, wrist, sternoclavicular and knee joints -absorbs shock, guides bone movements and distributes forces

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(2) Accessory structures ③ Articular fat pads - adipose tissue pads that protect the articular cartilage, as seen in the

infrapatellar fat pad in the knee. ④Articular labrum –help to deepen articular surfaces

(2) Accessory structures ⑤ Synovial fold or synovial bursa • a small fluid-filled sac lined by synovial membrane. • provides a cushion between bones and tendons and/or muscles around a joint. • helps to reduce friction between the bones • allows free movement.

(2) Accessory structures ⑥Tendon sheaths cylinders of connective tissue lined with synovial membrane and wrapped around a tendon

Types of synovial Joints (Articulations) 1. Plane joints (Gliding joints,滑动关节) – Flat articular surfaces in which bones slide over each other • Acromioclavicular joint • Sternocostal joints between the 2nd and 7th • Wrists and ankles joints – Limited movement

1. Plane joints (Gliding joints,滑动关节)

Wrists

Joint between scaphoid and two trapezial bones

Ankles

Joint between cuneiform bones and metatarsal bones

2. Pivot Joint (rotary joint, 车轴关节) •

a joint that allows rotary movement and twisting movement

(1) Joints between radius and ulna which allow to move by pronation and supination. –

Proximal radioulnar joint

–

Distal radioulnar joint

2. Pivot Joint (rotary joint, 车轴关节) (2) atlanto-axial joint between the atlas and the axis which allows for turning of the head from side to side.

3. Hinge Joint (屈戌关节) •

A joint in which a convex part of one bone fits into a concave part of another, allowing motion in only one plane. –

The elbow joint between the humerus and ulna

–

Interphalangeal joints in hand and foot

•

Movement of flexion and extension.

•

Pivot and hinge joints can be both considered cylindrical joints.

4. Ellipsoid (Condyloid) Joints – an ovoid articular surface, or condyle, is received into an elliptical cavity. – permits movement in two planes, allowing flexion, extension, adduction, abduction, and circumduction. – The wrist joint – Metacarpophalangeal joints – Metatarsophalangeal joints

5. Saddle Joints (鞍状关节) – Each articular surface is shaped like a saddle, the opposing surfaces are reciprocally concaveconvex.

– provide stability to the bones while providing more flexibility than a hinge or gliding joint. – trapeziometacarpal joint at the base of the thumb.

6. Ball-and-Socket Joints (球窝关节) – Smooth hemispherical head fits within a

cuplike depression – Shoulder joint (head of humerus into glenoid cavity of scapula )

– Hip joint (head of femur into acetabulum of hip bone) – Rotary motion is possible in every direction (flexion, extension, abduction, adduction, circumflexion, and rotation )

Summary of synovial joints

1. Ball-and-Socket Joints 2. Ellipsoid (Condyloid) Joints

3. Saddle Joints 4. Hinge Joint 5. Pivot Joint

6. Plan joint 6

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Summary of Joint Classes Structural Class Fibrous

Characteristics Bones united by collagen fibers

Types 1. 2. 3.

Suture Syndesmosis gomphosis

Mobility 1. 2.

3.

Cartilaginous

Bone ends united by cartilage

1. 2.

Synovial

Bone ends covered with articular cartilage and enclosed within a capsule lined with a synovial membrane

1. 2. 3. 4. 5. 6.

Synchondrosi 1. s (hyaline) 2. Symphysis (fibrocartliage) Plane Hinge Pivot Condyloid Saddle Ball and socket

Immobile (synarthrosis) Slightly moveable (amphiarthrosis) Immobile

Immobile Slightly moveable

Freely moveable (diarthrosis) which depends on joint design

Types of joint movements 1. General motion 2. Special motions of the hands and feet

3. Other special motions

1. General motion (1) Gliding (sliding) – – – –

Gliding movements in the plane of articular surfaces The opposed surfaces of the bones are flat or almost flat Movement is limited by their tight joint capsules Small joints (acromioclavicular joint, wrists, ankles, sternocostals)

(2) Flexion / Extension •Flexion - Bending movement that decreases the angle between two parts. •Extension - The opposite of flexion; a straightening movement that increases the angle between body parts.

Flexion / Extension/

Flexion /Extension of the neck

FLEXION/EXTENSION OF THE VETEBRAL COLUMN

Extension

FLEXION EXTESION OF LIMBS

To knee joint

To hip joint

(3) Abduction / Adduction – Abduction - A motion that pulls a structure or part away from the midline of the body. – Adduction - A motion that pulls a structure or part towards the midline of the body, or towards the midline of a limb.

Abduction Adduction

(4) Rotation – Internal rotation (or medial rotation) of the shoulder or hip would point the toes or the flexed forearm inwards (towards the midline). – External rotation (or lateral rotation) is the opposite of Internal Rotation. It would turn the toes or the flexed forearm outwards (away from the midline). Internal rotation External rotation

(5) Elevation /Depression – Elevation - Movement in a superior direction. – Depression - Movement in an inferior direction, the opposite of elevation.

Elevation /Depression

2. Special motions of forearm and hands (1) Pronation /Supination –

Pronation - A rotation of the forearm that moves the palm from an anteriorfacing position to a posterior-facing position, or palm facing down.

–

Supination - The opposite of pronation, the rotation of the forearm so that the palm faces anteriorly, or palm facing up.

–

Opposition of thumb

2. Special motions of the feet (2)Dorsiflexion /Plantarflexion (Occurs at ankle). – Dorsiflexion - Flexion of the entire foot superiorly, as if taking one's foot off an automobile pedal. – Plantarflexion - Flexion of the entire foot inferiorly, as if pressing an automobile pedal.

(3) Inversion /Eversion – Eversion - the movement of the sole of the foot away from the median plane. – Inversion - the movement of the sole towards the median plane (same as when an ankle is twisted).

3.Other special motions (1) Protraction /Retraction – Protraction - Anterior movement of the arms at the shoulders. – Retraction - Posterior movement of the arms at the shoulders.

Protraction

(2)Circumduction – The circular movement of a body part. It consists of a combination of flexion, extension, adduction, and abduction. "Windmilling" the arms or rotating the hand from the wrist are examples of circumductive movement.