Ch.8 Joints Flashcards
Joint
- site where 2 or more bones articulate, bone and cartilage, bone and teeth
- Rigid and strong enough to hold the skeleton together
- Soft and flexible enough to allow mobility
Joint Classification
by Function or structure
Joint Classfication by Function
Based on amount of movement
1. Synarthroses= immovable
2. Amphiarthroses= slightly moveable
3. Diarthroses = freely moving
Joint Classification by Structure
- Based on the type of connective
- Tissue binding and cavity presence
1. Fibrous joints
2. Cartilaginous joints
3. Synovial joints
Fibrous joints
Joint Classification by Structure
- connected by fibrous connective tissue
- no cavity present
- generally synarthroses
Types of fibrous joints
- Sutures: short fibers usually ossifies (synostosis)
- Syndesmoses: short ligaments
- Gomphoses: peg-in-socket
Cartilaginous joints
Joint Classification by Structure
-connected by cartilage
- no cavity present
- generally synarthroses to amphiarthroses
Types of Cartilaginous joints
Two types:
1. synchondrosis: bones connected by hyaline cartilage
2. symphysis: midline of the body
articular cartilage and a fibrocartilage pad
Synovial joints
Joint Classification by Structure
- fluid filled cavity present
- most common
- generally diarthroses
- Bones act as levers against which skeletal muscles pull
- Muscles are attached to at least 2 bones & contract across the joint
- Origin: attachment to the bone that
does not move when muscle contracts - Insertion: attachment to the bone that moves during contraction
Synovial joint structure
- Articular cartilage
- Synovial cavity filled with synovial fluid
- Articular capsule:
– outer fibrous capsule
– inner synovial membrane - may have associated fatty pads, menisci (fibrocartilage pad), bursa, tendon sheaths
Factors that stabilize synovial joints
- Shape of the articulating surfaces
- Reinforcing ligaments
- Tone in muscles crossing the joint
Types of movement
- Gliding = one flat surface slips smoothly across another
- Ex: carpals and tarsals - Rotation = moving around an axis
- Ex: head - Angular = causes increase or decrease in angle between 2 bones
- Extension: moving leg foward/ moving shoulder or head backward
- Flexion: moving leg backward/ moving shoulder or head foward
Classification of synovial joints
- Plane joint
- Hinge joint
- Pivot joint
- Condyloid joint
- Saddle joint
- Ball and Socket joint
Plane joint
Classification of synovial joints
- Flat articulating surfaces
- Gliding motion
Hinge joint
Classification of synovial joints
- Cylindrical projection on one bone fits in a trough on another bone
- Allows uniaxial angular motions: flexion and extension
Pivot joint
Classification of synovial joints
- Rounded projection of one bone fits into sleeve/ring of another
- Allows rotation
- Ex: neck or head
Condyloid joint
Classification of synovial joints
- Oval articular surface of one bone fits into concave depression of another
- Allows all angular motions
Saddle joint
Classification of synovial joints
- Complimentary concave and convex areas on each bone
- Allows all angular motions
Ball-and-socket
Classification of synovial joints
- Spherical head of one bone fits into a deep cavity of another bone
- Allows all motions
TMJ (temperomadibular joint)
Hinge and side to side lateral grinding
Sprain
Injury –> part of homeostasis
- ligament reinforcing a joint is stretched or torn
- Lumbar, ankle, knee are common
- Slow healing
Dislocation
Injury –> part of homeostasis
- bones out of normal position
- Shoulder & fingers most common
- Must be put back in place
- Displaces more easily next time
Bursitis & Tendonitis
Degenerative Disorder
Inflammations
Arthritis
Degenerative Disorder
- diseases that damage the joint
- 100 different kinds
- Very common (1 in 7 Americans)
Osteoarthritis
type of Arthritis
- Age related
- Little inflammation
- Cartilage wears away exposing bone
- Spurs develop
- More women than men
- Treated mostly with pain relievers
Rheumatoid arthritis
type of Arthritis
- Autoimmune disease
- Starts ~ age 45
- 3X more women than men
- Inflammatory
- Starts with stiff fingers, wrist, ankle, feet
- Scars in joint cavity ossify and bones fuse
- Treated with anti-inflammatory drugs and pain relievers
Gouty arthritis
type of Arthritis
- Metabolic disorder
- More men than women
- Uric acid deposited in cavity
- Starts with inflammation in big toe
- Probably genetic
- Several effective drug therapies
