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Anatomy and Physiology, Seventh Edition

Rod R. SeeleyIdaho State UniversityTrent D. StephensIdaho State UniversityPhilip TatePhoenix College

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.

Chapter 08Chapter 08

Lecture OutlineLecture Outline**

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Articulations or Joints

• Articulation or Joint– Place where two bones (or bone and cartilage)

come together• Arthrology = study of the joints• Kinesiology = study of musculoskeletal• Functions of joints

– Give the skeleton mobility– Hold the skeleton together

• Structure correlated with movement

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Classification of Joints• Structural classes: based on type of

connective tissue type that binds bones and whether or not a joint cavity is present– Fibrous– Cartilaginous– Synovial

• Functional classes: based on degree of motion – Synarthrosis: non-movable– Amphiarthrosis: slightly movable– Diarthrosis: freely movable

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Fibrous Joints

• Characteristics– United by fibrous connective tissue– Have no joint cavity– Move little or none

• Types: – Sutures– Syndesmoses– Gomphoses

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Fibrous Joints: Sutures • Types of sutures

– Serrated: Opposing bones interdigitate (Sagittal suture)– Lap: Over lapping beveled edges (Squamosal suture)– Plane: Straight, non-over lapping edges (Intermaxillary suture)

• Periosteum of one bone is continuous with the per iosteum of the other .

• In adults may ossify completely: synostosis. • Fontanels: membranous areas in the suture between

bones. A llow change in shape of head during bir th and rapid growth of the brain after bir th.

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Types of Sutures

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Fibrous Joints: Syndesmoses

• Two bones joined by ligament– Interosseous membrane

• Most moveable of fibrous joints

• Examples: radioulnar joint and tibiofibular joints

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Fibrous Joints: Gomphoses

• Specialized joints• Pegs that fit into sockets• Periodontal

ligaments: hold teeth in place

• Inflammations– Gingivitis leads to…– Periodontal disease

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Cartilaginous Joints

• Bones are joined by cartilage

• Lack a joint cavity• Types

– Synchondroses: bound by hyaline cartilage

– Symphyses: bound by fibrocartilage

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Cartilaginous Joints: Synchondroses

• Joined by hyaline cartilage

• Little or no movement• Some are temporary

and are replaced by synostoses

• Some are permanent• Some like

costochondral joints develop into synovial joints

• Examples: Epiphyseal plates, 1st sternocostal

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Cartilaginous Joints: Symphyses

• Fibrocartilage uniting two bones

• Slightly movable• Examples:

symphysis pubis, between the manubrium and the body of the sternum, intervertebral disks.

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Synovial Joints

• Contain synovial fluid in a joint cavity called the synovial cavity

• Allow considerable movement (diarthroses)

• Most joints that unite bones of appendicular skeleton reflecting greater mobility of appendicular skeleton compared to axial

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Structure of Synovial

Joints

• Articular cartilage: hyaline; provides smooth surface on epiphysis

• Joint cavity: synovial; encloses articular surfaces

• Articular Capsule encloses joint cavity

– Fibrous capsule: • dense irregular connective tissue• continuous with periosteum. • Portions may thicken to form ligaments.

– Synovial membrane and fluid:• Thin, delicate membrane• lines inside of joint capsule.

• Synovial fluid: – complex mixture of polysaccharides,

proteins, fat and cells. Hyaluronic acid- slippery.

• No blood vessels or nerves in articular cartilages; nutrients derived from nearby blood vessels and synovial fluid

• Nerves in capsule help brain know position of joints (proprioception)

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Accessory Structures

• Bursae– Pockets of synovial membrane and fluid that extend from the

joint. Found in areas of friction– Bursitis

• Ligaments and tendons: stabilization• Articular discs: temperomandibular,

sternoclavicular, acromioclavicular• Menisci: fibrocartilaginous pads in the knee.• Tendon sheaths: synovial sacs that surround

tendons as they pass near or over bone

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Synovial Joints: Friction-Reducing Structures

Figure 8.4

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Types of Movement

• Gliding: in plane joints; slight movement• Angular

– Flexion and Extension• Hyperextension• Plantar and Dorsiflexion

– Abduction and Adduction

• Circular– Rotation– Pronation and Supination– Circumduction

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Flexion and Extension

• Flexion: movement of a body part anterior to the coronal plane

• Extension: movement of a body part posterior to the coronal plane

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Dorsiflexion and Plantar Flexion

• Exceptions to definition– Plantar flexion:

standing on the toes– Dorsiflexion: foot

lifted toward the shin

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Abduction and Adduction

• Abduction: movement away from the midline

• Adduction: movement toward the midline

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Circular Movements: Rotation, Pronation and Supination

• Rotation: turning of a structure on its long axis– Examples: rotation of the

head, humerus, entire body– Medial and lateral rotation;

example, the rotation of the arm

• Pronation/Supination: refer to unique rotation of the forearm– Pronation: palm faces

posteriorly– Supination: palm faces

anteriorly

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Circular Movement: Circumduction

• Combination of flexion, extension, abduction, adduction

• Appendage describes a cone

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Special Movements

• Unique to only one or two joints• Types

– Elevation and Depression– Protraction and Retraction– Excursion– Opposition and Reposition– Inversion and Eversion

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Elevation and Depression

• Elevation: moves a structure superior

• Depression: moves a structure inferior

• Examples: shrugging the shoulders, opening and closing the mouth

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Protraction and Retraction

• Protraction: gliding motion anteriorly

• Retraction: moves structure back to anatomic position or even further posteriorly

• Examples: scapulae and mandibles

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Excursion

• Lateral: moving mandible to the right or left of midline

• Medial: return the mandible to the midline

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Opposition and Reposition

• Opposition: movement of thumb and little finger toward each other

• Reposition: return to anatomical position

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Inversion and Eversion

• Inversion: turning the ankle so the plantar surface of foot faces medially

• Eversion: turning the ankle so the plantar surface of foot faces laterally

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Movements at Synovial joints

• Monoaxial: occurring around one axis• Biaxial: occurring around two axes at

right angles to each other• Multiaxial: occurring around several

axes• See Table 8.2 in text

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Types of Synovial Joints:Plane Joints

• Plane or gliding joints– Monaxial. One flat bone

surface glides or slips over another similar surface

– Sometimes considered an amphiarthrosis

– Examples: intervertebral, intercarpal, intertarsal acromioclavicular, carpometacarpal, tarsometatarsal,

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Hinge and Pivot Joints• Hinge joints

– Monaxial– Convex cylinder in one

bone; corresponding concavity in the other

– Example: elbow, ankle, interphalangeal

• Pivot joints– Monaxial. Rotation around

a single axis.– Cylindrical bony process

rotating within a circle of bone and ligament

– Example: articulation between dens of axis and atlas (atlantoaxial), proximal radioulnar

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Saddle joints• Each articular surface is shaped like a saddle; • Trapeziometacarpal joint at base of the thumb

Types of Synovial Joints:

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Ball-and-Socket and Ellipsoid Joints

• Ball-and-socket– Smooth heispherical head fits

within a cuplike depression– Multiaxial– Examples: shoulder and hip joints

• Condyloid (ellipsoid) joint– Oval convex surface on one bone

fits into a similarly shaped depression on the next

• Atlantooccipital joint (C1-C2)• Metacarpophalangeal joints

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Shoulder (Glenohumeral)

Joint

• Most freely moveable joint in body– Shallowness and looseness– Stability is reduced– Deepened by glenoid labrum, a rim of

cartilage built up around glenoid cavity

• Supported by rotator cuff musculature– tendons fuse to joint capsule – Stabilize and strengthen it– supraspinatus, infraspinatus, teres

minor and subscapularis,• Bursae: subacromial and subscapular• Tendon of biceps brachii passes

through the joint capsule• Flexion/extension,

abduction/adduction, rotation, circumduction

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Tendons of Rotator Cuff Muscles

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The Knee Joint• Most complex diarthrosis

– patellofemoral = gliding joint– tibiofemoral = gliding with slight

rotation and gliding possible in flexed position

• Joint capsule anteriorly consists of patella and extensions of quadriceps femoris tendon

• Capsule strengthened by extracapsular and intracapsular ligaments

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Knee, cont.• Cruciate ligaments:

extend between intercondylar eminence of tibia and fossa of the femur– Anterior cruciate

ligament (ACL). Prevents anterior displacement of tibia

– Posterior cruciate ligament (PCL). Prevents posterior displacement of tibia

• Collateral and popliteal ligaments: along with tendons of thigh muscles strengthen the joint

• Bursae: may result in slow accumulation of fluid in the joint (water on the knee)

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Knee Joint – Anterior and Posterior Views

• Anterior and lateral cruciate ligaments limit anterior and posterior sliding movements

• Medial and lateral collateral ligaments prevent rotation of extended knee

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Knee Joint – Superior View

• Medial and lateral meniscus absorb shock and shape joint

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Knee Injuries and Disorders• Football injuries: often tear

the tibial collateral ligament, the anterior cruciate ligament, and damage the medial meniscus

• Bursitis• Chondromalacia:

softening of cartilage due to abnormal movement of the patella or to accumulation of fluid in fat pad posterior to patella

• Hemarthrosis: acute accumulation of blood in joint

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Effects of Aging on Joints

• Tissue repair slows; rate of new blood vessel development decreases

• Articular cartilages wear down and matrix becomes more rigid

• Production of synovial fluid declines• Ligaments and tendons become shorter and

less flexible: decrease in range of motion (ROM)

• Muscles around joints weaken• A decrease in activity causes less flexibility

and decreased ROM

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Sprains

• The ligaments reinforcing a joint are stretched or torn

• Partially torn ligaments slowly repair themselves

• Completely torn ligaments require prompt surgical repair

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Cartilage Injuries

• The snap and pop of overstressed cartilage

• Common aerobics injury• Repaired with arthroscopic surgery

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Dislocations

• Occur when bones are forced out of alignment

• Usually accompanied by sprains, inflammation, and joint immobilization

• Caused by serious falls and are common sports injuries

• Subluxation – partial dislocation of a joint

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Inflammatory and Degenerative Conditions

• Bursitis– An inflammation of a bursa, usually caused by a

blow or friction– Symptoms are pain and swelling– Treated with anti-inflammatory drugs; excessive

fluid may be aspirated

• Tendonitis– Inflammation of tendon sheaths typically caused

by overuse– Symptoms and treatment are similar to bursitis

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Arthritis

• More than 100 different types of inflammatory or degenerative diseases that damage the joints

• Most widespread crippling disease in the U.S.• Symptoms – pain, stiffness, and swelling of a

joint• Acute forms are caused by bacteria and are

treated with antibiotics• Chronic forms include osteoarthritis,

rheumatoid arthritis, and gouty arthritis

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Osteoarthritis (OA)

• Most common chronic arthritis; often called “wear-and-tear” arthritis

• Affects women more than men• 85% of all Americans develop OA• More prevalent in the aged, and is

probably related to the normal aging process

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Osteoarthritis: Course

• OA reflects the years of abrasion and compression causing increased production of metalloproteinase enzymes that break down cartilage

• As one ages, cartilage is destroyed more quickly than it is replaced

• The exposed bone ends thicken, enlarge, form bone spurs, and restrict movement

• Joints most affected are the cervical and lumbar spine, fingers, knuckles, knees, and hips

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Rheumatoid Arthritis (RA)

• Chronic, inflammatory, autoimmune disease of unknown cause, with an insidious onset

• Usually arises between the ages of 40 to 50, but may occur at any age

• Signs and symptoms include joint tenderness, anemia, osteoporosis, muscle atrophy, and cardiovascular problems– The course of RA is marked with exacerbations

and remissions

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Rheumatoid Arthritis: Course

• RA begins with synovitis of the affected joint• Inflammatory chemicals are inappropriately released• Inflammatory blood cells migrate to the joint, causing

swelling• Inflamed synovial membrane thickens into a pannus• Pannus erodes cartilage, scar tissue forms,

articulating bone ends connect• The end result, ankylosis, produces bent, deformed

fingers

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Rheumatoid Arthritis

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Rheumatoid Arthritis: Treatment

• Conservative therapy – aspirin, long-term use of antibiotics, and physical therapy

• Progressive treatment – anti-inflammatory drugs or immunosuppressants

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Gouty Arthritis

• Deposition of uric acid crystals in joints and soft tissues, followed by an inflammation response

• Typically, gouty arthritis affects the joint at the base of the great toe

• In untreated gouty arthritis, the bone ends fuse and immobilize the joint

• Treatment – colchicine, nonsteroidal anti-inflammatory drugs, and glucocorticoids