1. Joints or Articulations
Chapter 8
Joints or Articulations

2. Why do we need them? Articulations are junctions between bones
They bind parts of skeletal system together
Make bone growth possible
Permit parts of the skeleton to change shape during childbirth
Enable body to move in response to skeletal muscle contraction
8-2

3. Classification of Joints-Structural and Functional
Fibrous Joints-lack a synovial cavity and permit little to no movement
dense connective tissues connect bones
between bones in close contact
synarthrotic
immovable
amphiarthrotic
slightly movable
diarthrotic
freely movable
Cartilaginous Joints-lack a synovial cavity and allow little or no movement
hyaline cartilage or fibrocartilage connect bones form a tight connection
Synovial Joints-have a joint cavity
most complex
allow free movement
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4. Fibrous Joints 3 Types Syndesmosis Suture Gomphosis Syndesmosis
long fibers connect bones
amphiarthrotic
distal ends of tibia and fibula
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5. Fibrous Joints Suture between flat bones (skull) synarthrotic
thin layer of connective tissue connects bones
Metopic suture of frontal bone usually fuses completely
Gomphosis
cone-shaped bony process in a socket
tooth in jawbone
synarthrotic
8-5

6. Cartilaginous Joints 2 Types Synchondrosis Symphysis Synchondrosis
bands of hyaline cartilage unite bones
epiphyseal plate (temporary)
between manubrium and first rib
synarthrotic (immoveable)
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7. Cartilaginous Joints Symphysis pad of fibrocartilage between bones
pubis symphysis
joint between bodies of vertebrae
amphiarthrotic
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8. Synovial Joints diarthrotic joint cavity allows joint to move freely
synovial fluid-reduce friction, absorb
shocks, supply oxygen and remove waste
from chondrocytes
joint capsule
synovial membrane-inner layer
of the articular capsule
Articular cartilage covers ends
bursae-reduce friction, cushion movement
8-8

9. Types of Synovial Joints
Condyloid Joint
between metacarpals and phalanges
Oval shaped projection fits into oval shaped depression
Ball-and-Socket Joint
hip
shoulder
Permit multiaxial movement
8-9

10. Types of Synovial Joints
Gliding Joint or Planar Joints
between carpals
between tarsals
Articular surfaces are flat to slightly
curved
Hinge Joint
elbow
between phalanges
8-10

11. Types of Synovial Joints
Pivot Joint
between proximal ends of radius and ulna and between axis and atlas
Saddle Joint
between carpal and metacarpal of thumb
Modified condylar joint
8-11

12. Types of Joint Movements
abduction- movement away from midline
Adduction-movement toward midline
dorsiflexion-bend the foot at the ankle (stand on heels)
Plantarflexion-bend foot at ankle toward inferior (stand on toes)
flexion-decrease the angle
Extension-increase angle of joint
Hyperextension-continue extension beyond anatomical position
8-12

13. Types of Joint Movements
rotation-bone turns on longitudial axis
Circumduction-one end remains stationary
supination –palm is up (hold soup)
pronation-palm is down or facing the rear
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14. Types of Joint Movements
eversion-turning sole of foot laterally
inversion-turning sole medially
protraction-/retraction
elevation/depression
8-14

15. Shoulder Joint ball-and-socket
head of humerus and glenoid cavity of scapula
loose joint capsule
4 bursae reduce friction-look up names……
ligaments prevent displacement
very wide range of movement
Rotator cuff- supraspinatus, infraspinatus, teres minor, subscapularis, work together to join scapula to humerus
8-15

16. Shoulder Joint
8-16

17. Elbow Joint hinge joint gliding joint flexion and extension
trochlea of humerus
trochlear notch of ulna
gliding joint
capitulum of humerus
head of radius
flexion and extension
many reinforcing ligaments
Including radial collateral ligament
and ulnar collateral ligament
stable joint
8-17

18. Elbow Joint
8-18

19. Hip Joint ball-and-socket joint head of femur acetabulum
Acetabular labrum is a fibrocartilage rim that increases depth of socket
heavy joint capsule
many reinforcing ligaments-like ischiofemoral and iliofemoral ligament
less freedom of movement than shoulder joint
8-19

20. Hip Joint
8-20

21. Knee Joint largest joint and most complex
medial and lateral condyles of distal end of femur
medial and lateral condyles of proximal end of tibia
femur articulates anteriorly with patella
modified hinge joint
flexion/extension/little rotation
strengthened by many ligaments and tendons-PCL, ACL, tibial collateral ligament, fibular collateral ligament,
menisci separate femur and tibia
bursae include pre-patellar bursae which is often damaged when you bump the anterior knee
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22. Knee Joint
8-22

23. Life-Span Changes Joint stiffness is an early sign of aging
Regular exercise can prevent stiffness
Fibrous joints first to strengthen over a lifetime
Changes in symphysis joints of vertebral column diminish flexibility and decrease height
Synovial joints lose elasticity
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24. Clinical Application Joint Disorders Sprains
damage to cartilage, ligaments, or tendons associated with joints
forceful twisting of joint
Bursitis
inflammation of a bursa
overuse of a joint
Arthritis
inflamed, swollen, painful joints
Rheumatoid Arthritis-RA, autoimmune disease
Osteoarthritis or OA-most common, wear and tear
Gout-often strikes big toe, peanuts can aggravate this
8-24

25. Disorders Cartilage injury-usually require surgery
Dislocation (luxation)-forced bone out of alignment, usually downward displacement
Partial dislocation is subluxation
Bursitis-also known as: housemaids knee, tennis elbow, student elbow (olecranon bursitis)
Tendonitis-inflammation of tendon sheath, same type symptoms as bursitis