Joints Flashcards
Define Articulation
Site where 2 or more bones meet
Function of joints
Give skeleton mobility
Hold skeleton together
Joints are classified on allowed movement
Name 3 classifications
Synarthroses - immoveable
Amphiarthroses - slightly moveable
Diarthroses - freely movable
Name 3 structural classifications
Fibrous
Cartilaginous
Synovial
Define fibrous joints
Bones joined by dense fibrous connective tissue
No joint cavity
Most are synarthrotic (immovable)
3 types
- sutures
- syndesmoses
- gomphoses
Fibrous Joints: sutures
- Rigid, interlocking joints containing short connective tissue fibers
- Allow for growth during youth
- In middle age, sutures ossify and are called synostoses
Fibrous Joints: Syndesmoses
Bones connected by ligaments (bands of fibrous tissue)
Movement varies from immovable to slightly movable
Examples:
- Synarthrotic distal tibiofibular joint
- Diarthrotic interosseous connection between radius and ulna
Fibrous Joints: Gomphoses
Peg-in-socket joints of teeth in alveolar sockets
Fibrous connection is the periodontal ligament
Cartilaginous Joints
- Bones unitd by cartilage
- NO JOINT CAVITY
- 2 types
1. Synchondroses - A bar or plate of hyaline cartilage unites the bone
2. Symphyses - Hyaline cartilage covers the articulating surfaces and is fused to an intervening pad of fibrocartilage, slight movement
Synovial Joints
All are diarthrotic (free movable)
Include all limb joints; most joints of the body
Distinguishing features of Synovial Joints
- Articular cartilage: hyaline
- Joint (synovial) cavity; small potential space
- Articular capsule
- Synovial fluid - viscous slippery filtrate of plasma + hyaluronic acid lubricates and nourishes articular cartilage
- Reinforcing ligaments - capsular, extracapsular, intracapsular
- Rich nerve and blood supply-detect pain, joint position and stretch, capillaries beds make synovial fluid
Synovial Joints: friction-reducing structures
What is a bursae?
- flattened, fibrous sacs lined with synovial membranes
- contain synovial fluid
- commonly act “ball bearings” where ligaments, muscles, skin, tendon, or bones rub together
Synovial Joints: Friction-reducing structures:
Tendon Sheath: What is this?
Elongated bursa that wraps completely around a tendon
Stabilizing Factors at synovial joints (3)
- Shapes of articular surface (minor role)
- Ligament number and location(limited role)
- Muscle tone, which keeps tendons that cross the joint taut
—-Extremely important in reinforcing should and knee joints and arches of the foot
Name the ranges of motion
- Nonaxial - slipping movements only
- Uniaxial - movement in 1 plane
- Biaxial - movement in 2 planes
- multiaxial- movement in or around 3 planes
Structural and Functional Characteristics of body joints
Look at the pictures
Movements of Synovial Joints (4)
- Gliding
- Angular movements:
Flexion, extension, hyperextension
Adbduction, adduction
circumduction
- Rotation
Medial and lateral rotation
- Special movements
Supination, pronation
Doriflexion, plantar flexion of foot
Inversion, eversion
Protraction, retraction
Elevation, depression
Opposition
What is gliding movements?
One flat bone surface glides or slips over another similar surface
Example:
intercarpal joints
intertarsal joints
between articular processes of vertebrae
Angular Movements Description
- Movements that occur along the saggital plane:
1. Flexion - decreases the angle of the joint
2. Extension - increases the angle of the joint
3. Hyperextension - excessive extension beyond normal range of motion
Angular Movements
Occur along the frontal plane:
Abdction: movement away from the midline
Adduction: movement toward the midline
Circumduction: flexion + abduction+extension+adduction of a limb so as to describe a cone in space
Rotation
The turning of a bone around its own long axis
Examples
Between c1 and c2 vertebrae
Rotation of humerus and femur
Special movements
movements of radius and ulna
Supination - rotating palms to be facing forward - hold a bowl of soup
Pronation - palms posterior -pro basketball players dribble with a pronated hand
Movements of foot:
Dorsiflexion (upward)
Plantar Flexion (down)
Pronation - flat footed
supination - high arch
inversion - turn sole medially
eversion - turn sole laterally
Picture of inversion and eversion of foot
look at picture
What are movements in transverse plane?
Protraction - anterior movement
Retraction - posterior movement
What is elevation and depression?
Elevation (lifting body part superiorly)
Depression (moving body part inferiorly)
What is opposition of the thumb?
movement in the saddle joint so that the thumb touches the tips of the other fingers
Classification of synovial joints based on shape of articular surfaces (6)
plane
hinge
pivot
condyloid
saddle
ball and socket
What are plane joints?
- Nonaxial joint
- flat articular sufaces
- short gliding movements
Hinge Joints
- Uniaxial joint
- motion along a single plane
- flexion and extension only
Pivot Joints
- rounded end of one bone conforms to a sleeve or ring of another bone
- uniaxial movement only
Condyloid Joints (ellispsoidal)
- biaxial joint
- both articular surfaces are oval
permit all angular movements
Saddle joints
- biaxial
- allow greater freedom of moveent than condyloid joints
- each articular surface has both concave and convex areas
Ball and socket joints
multiaxial joint
most freely moving synovial joints
knee joint
- larges mosts complex joint of body
- three joints surrounded by a single joint cavity
—femoropatellar joint
—–plane joint
—–allows gliding motion during knee flexion
—lateral and medial tibiofemoral joints between femoral condyles and the C-shaped lateral and medial menisci (semilunal cartilages) of the tibia
—–allow flexion, extension, some rotation when knee is partly flexed
superior view of the right tibia in the knee joint showing menisci and cruciate ligaments
See picture
Knee joint
- atleast 12 associated bursae
- capsule is reinforced by muscle tendons
- joint capsule is thin and absent anteriorly
- anteriorly, the quadriceps tendon gives rise to
—-lateral and medial patellar ritinacula
—-patellar ligament
What does the capsular and extracapsular ligaments do?
help prevent hyperextension
what does the intracapsular ligament do?
- anterior and posterior cruciate ligaments
- prevent anterior-posterior displacement
- reside outside the synovial cavity
Shoulder Joint (Glenohumeral)
- ball and socket joint: head of humerus and glenoid fossa of the scapula
- stability os sacrificed for greater freedom of movement
Anterior view of right shoulder joint capsule
look at picture
Lateral view of socket of right shoulder joint, humerus removed
See picture
Hip (coxal) joint
- ball and socket joint
- head of the femur articulates with the acetabulum
- good range of motion, but limited by the deep socket
- acetabular labrum - enhances depth of socket
See picture of Posterior view of right hip joint, capsule in place
See picture
See anterior view of right hip joint, capsule in place
see picture
Temporomandibular Joint
- Mandibular condyle articulates with the temporal bone
- Two types of movement
—-Hinge - depression and elevation of mandible
—Gliding —e.g. side-to-side (lateral excursion) grinding teeth
-Most easily dislocated joint in the body
Common Joint Injuries
Sprains
Cartilage Tears
Dislocations (luxations)
Subluxation
What are sprains?
How do we heal?
ligaments are stretched or torn
partial tears slowly repair themselves
complete ruptures require prompt surgical repair
Cartilage tears
Due to compression and shear stress
Fragments may cause joint to lock or bind
cartilage rarely repairs itself
repaired with arthroscopic surgury
Dislocations (luxations)
Occur when bones are forced out of alignment
accompanied by sprains, inflammation, joint immobilization
caused by serious falls or playing sports
Subluxation
partial dislocation of joint
Inflammatory and Degenerative Conditions
Name 3
Bursitis
Tendonitis
Arthritis
Bursitis
Inflammation of a bursa, usually caused by a blow or friction
Treated with rest and ice and, if severe, anti-inflammatory drugs
Tendonitis
Inflammation of tendon sheaths typically caused by overuse
Symptoms and treatment similar to bursitis
Arthritis - General explanation
100 different types of inflammatory or degenerative diseases that damage joints
Most widespread crippling disease in USA
Symptoms: pain, stiffness, swelling of joint
Acute forms: caused by bacteria, treated with antibiotics
Chronic forms: osteoarthritis, rheumatoid arthritis, gouty arthritis
Osteoarthritis (OA)
- Common, irreversible, degenerative arthritis - wear and tear
- 85% of all Americans develop 0A, more women than men
- Probably related to normal aging process
- More cartilage is destroyed than replaced in badly aligned or overworked joints
- exposed bone end thickens, enlarge, form bone spurs, restrict movement
- treatment: moderate activity, mild pain relievers, capsaicin creams, surgury
Rheumatoid Arthrisitis (RA)
- Chronic, inflammatory, autoimmune disease - unknown cause
- Usually arises between 40 and 50 but may occur at any age, 3 times more women as men
- Signs and symptoms include joint pain, swelling (usually bilateral), anemia, osteoporosis, muscle weakness, cardiovascular problems
- RA begins with synovitis of affected joint
- Inflammatory blood cells migrate to the joint, release inflammatory chemicals
- Inflammed synovial membrane thickens into a pannus
- Pannus erodes cartilage, scar tissue forms, articulating bone ends connect (ankylosis)
Treatment of RA
- Conservative therapy: asprin, long-term use of antibiotics and PT
- Progressive treatment: anti-inflammatory drugs or immunosuppressants
- New biological response modifier drugs neutralize inflammatory chemicals
Gouty Arthritis
- Deposition of uric acid crystals in joints and soft tissues, followed by inflammation
- more common in men
- typically affects the joint at the base of great toe
- In untreated gouty arthritis, the bone ends fuse and immobilize the joint
- treatment: drugs, plenty of water, avoid alcohol
Lyme Disease
- caused by bacteria transmitted by deer tick
- symptoms: skin rash, flu like symptoms, foggy thinking
- may lead to joint pain and arthritis
- treatment: antibiotics
