Download Articulations / Joints

Articulations / Joints
Joints - Articulations
• Where 2 bones meet. Classified by degree of motion
(functional) and major connective tissue types that
bind the bones together (structural)
• Fibrous joints – united by fibrous tissue and has little
to no movement. Example – Sutures, gomphosis
(teeth), syndesmosis –tibia / fibula distal articulation
• Cartilaginous joints – united by cartilage. Only slight
movement. Synchondrosis – epiphyseal plate,
Symphysis - pubic
• Synovial joint – freely moveable contains synovial
fluid in a cavity surrounding bones. Examples –
shoulder, knee
Function classification
• Synarthrosis – immovable joint
• Amphiarthrosis – slightly movable
• Diarthrosis – freely movable.
• -sis is replaced with –ses for the plural form
Capsular nature of a synovial joint
Cavity (synovial joint) enclosed by a capsule (2 layers)
• Fibrous cartilage – dense irregular, encloses cavity
• Ligaments – connects bone to bone
• Tendons – connect muscles to bone
• Articular cartilage – hyaline cartilage at ends of
bones
• Synovial membranes –areolar, produced synovial
fluid for lubrication, nutrients, and metabolic waste
removal
Capsular nature of a synovial joint
• Articular disc / meniscus – pads of
fibrocartilage that lie between the articular
surfaces of the bones (lateral and medial)
• Bursae – closed sacs, with a synovial lining.
Subcutaneous (patella), subfascial – between
muscles, Subtendinous – tendon and process
or tendon
Synovial joint
The knee joint
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Patellar ligament – patella to tibia, anterior
Oblique popliteal ligament - posterior surface
Acruate popliteal ligament – lower later post.
Medial collateral ligament – medial (inside)
Lateral collateral ligament – lateral (outside)
Anterior cruciate ligament – tibia, post and
laterally to the femur, 70% serious injury
• Posterior cruciate ligament – tibia, anterior and
medial to the femur
• (menisci, bursae)
Knee joint
Synovial joints
Joint
Description
Example
Planar
Flat or slightly curved
Wrist, ankle
Hinge
convex one concave other elbow, knee
Ball and Socket
ball one socket other
shoulder, hip
Saddle
2 saddle at right angles
thumb, wrist
Pivot
Rotation on axis
Convex oval projection in
a concave oval fossa
head (no)
Metacarpal,
phalanges
Condyloid
Major joint movement
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Flexion – decrease in the angle
Extension – increase in the angle
Hyperextension – extension beyond position
Abduction – away from midline
Adduction – toward midline
Pronation – palm down
Supination – palm up
Eversion – foot out
Inversion – foot in
Dorsiflexion – foot up
Plantar flexion – foot down
Major joint movement con’t
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Rotation – turn around long bone axis
Protraction – structure glides to anterior (front)
Retraction – structure glides to posterior (back)
Elevation – move structure superior (up)
Depression – move structure inferior (down)
Excursion – move one side to another
Opposition – move of thumb to pinky
Reposition – return thumb / pinky to normal
Circumduction – arm / hip circles
Aging and joints
• Decreased synovial fluid
• Articular cartilage thins (glucosamine
chondroitin / shark cartilage)
• Ligaments shorten and lose flexibility
• Degenerative changes in vertebral column,
hunched – over posture
Stretching and aerobic exercise that help with
range of motion, help to minimize aging
effects
Joint Disorders
• Bursitis – inflammation of bursa (elbow and shoulder)
• Arthritis – inflammation of the whole joint
• Rheumatoid arthritis – connective tissue disorder (excess
growth) with severe inflammation of small joints
• Rheumatic fever – bacterial (strep) infection that causes
RA if left undetected.
• Fibrositis – inflammation of fibrous connective tissue in a
joint; “rheumatism,” lumbago – lower back
• Osteoarthritis – Degenerative joint, elderly, weight –
bearing joints
Joint disorders continued
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Gout – uric acid crystals in joint at large toe base
Sprain – twisting tears ligaments (ankles and wrists)
Strain – stretched or partially torn muscle
Slipped Disk – intervertebral disk protrudes or moves
out of place, pressure on nerve
• Dislocation – temporary displaced bone
• Cumulative trauma disorder – ongoing “repetitive” or
overuse damage to soft tissue. Carpal tunnel- medial
nerve as it passes through the carpal tunnel