Transcript a12b Joints Part B

Joints (Articulations)
• Functions of joints
• Classifying Joints: Functional or
Structural
• Naming Movements of Bones Around
Joints
• Types of Joints Based on Movement
• Selected Key Joints: Shoulder, Elbow,
Hip, Knee
• Joint Injuries
• Chronic Joint Conditions: Arthritis
Types of Synovial Joints Based on Shape
Types of Synovial Joints Based on Shape
Plain hinge joints pivot on condyloid saddle ball-sockets.
Joints (Articulations)
• Functions of joints
• Classifying Joints: Functional or
Structural
• Naming Movements of Bones Around
Joints
• Types of Joints Based on Movement
• Selected Key Joints: Shoulder, Elbow,
Hip, Knee
• Joint Injuries
• Chronic Joint Conditions: Arthritis
Shoulder (Glenohumeral) Joint
• Bones and features involved
•
Head of humerus and glenoid fossa of the
scapula
• Type of joint
•
Ball-and-socket joint
• Stability/strength of joint
•
Coracohumeral ligament supports the
weight of the upper limb
•
Three glenohumeral ligaments—weak anterior
reinforcements
Reinforced by tendon of the long head of
biceps and 4 rotator cuff tendons
Four rotator cuff tendons encircle the shoulder
joint:
•
•
•
Stability is sacrificed for greater freedom of
movement
• Allowable movements
•
Diarthrotic
•
Flexion, extension, adduction, abduction,
medial and lateral rotation
Elbow Joint
• Bones and features involved
•
Radius and ulna articulate with the humerus
•
Hinge at trochlear notch of ulna and
trochlea of humerus
• Type of joint
•
Hinge joint
• Stability/strength of joint
•
Anular ligament —surrounds head of
radius
•
Two capsular ligaments restrict sideto-side movement:
• Ulnar collateral ligament
• Radial collateral ligament
• Allowable movements
•
Diarthrotic
•
Flexion and extension only
Hip (Coxal) Joint
• Bones and features involved
•
Head of the femur articulates with the acetabulum
of the pelvis
• Type of joint
•
Ball-and-socket joint
• Stability/strength of joint
•
4 Reinforcing ligaments:
• Iliofemoral ligament
• Pubofemoral ligament
• Ischiofemoral ligament
• Ligamentum teres
• Allowable movements
•
Flexion, extension, rotation, adduction, abduction,
circumduction
•
Good range of motion, but limited by the deep
socket
•
Acetabular labrum (ring of cartilage around
cavity—enhances depth of socket, difficult to
dislocate
Knee Joint
• Bones and features involved
•
•
Largest, most complex joint of body
Three joints surrounded by a single joint
cavity: femoropatellar, lateral and medial
tibiofemoral joints
• Type of joint
•
Femoropatellar joint - plane joint with gliding
•
Lateral and medial tibiofemoral hinge joints
between the femoral condyles and the C-shaped
lateral and medial menisci (semilunar cartilages)
of the tibia
• Stability/strength of joint
•
Capsule is reinforced by muscle tendons:
•
Quadriceps and semimembranosus tendons
•
Joint capsule is thin and absent anteriorly
•
Anteriorly, the quadriceps tendon gives rise to
patellar ligament
•
Capsular and extracapsular ligaments prevent
hyperextension
•
Intracapsular ligaments
• Allowable movements
•
Diarthrotic
•
Allows flexion, extension, and some rotation
when knee is partly flexed
Joints (Articulations)
• Functions of joints
• Classifying Joints: Functional or
Structural
• Naming Movements of Bones Around
Joints
• Types of Joints Based on Movement
• Selected Key Joints: Shoulder, Elbow,
Hip, Knee
• Joint Injuries
• Chronic Joint Conditions: Arthritis
Common Joint Injuries
• Sprains
•
The 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 surgery
• Dislocations (luxations)
•
Occur when bones are forced out of alignment
•
Accompanied by sprains, inflammation, and joint
immobilization
•
Caused by serious falls or playing sports
• Subluxation—partial dislocation of a joint
Inflammatory and Degenerative Conditions
• Bursitis
• An inflammation of a bursa, usually caused by
a blow or friction
• Treated with rest and ice and, if severe, antiinflammatory drugs
• Tendonitis
• Inflammation of tendon sheaths typically
caused by overuse
• Symptoms and treatment similar to bursitis
Joints (Articulations)
• Functions of joints
• Classifying Joints: Functional or
Structural
• Naming Movements of Bones Around
Joints
• Types of Joints Based on Movement
• Selected Key Joints: Shoulder, Elbow,
Hip, Knee
• Joint Injuries
• Chronic Joint Conditions: Arthritis
Lyme Disease: Acute Arthritis
• Caused by bacteria
transmitted by the
bites of ticks
• Symptoms: skin rash,
flu-like symptoms,
and foggy thinking
• May lead to joint pain
and arthritis
• Treatment: antibiotics
Clinical Forms of Arthritis (Three Chronic Types)
•100 different types of inflammatory or degenerative diseases that damage joints
•Most widespread crippling disease in the U.S.
•Symptoms: pain, stiffness, and swelling of a joint
•Acute forms: caused by bacteria, treated with antibiotics
•Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis
1. Osteoarthritis
•
Most common chronic arthritis
•
Irreversible, degenerative (“wear-and-tear”)
arthritis
•
85% of all Americans develop OA, more women than
men
•
Probably related to the normal aging process
•
More cartilage is destroyed than replaced in badly
aligned or overworked joints
•
Exposed bone ends thicken, enlarge, form bone
spurs, and restrict movement
•
Treatment: moderate activity, mild pain relievers,
capsaicin creams, glucosamine and chondroitin
sulfate
Clinical Forms of Chronic Arthritis
2. Rheumatoid arthritis
• Chronic, inflammatory, autoimmune disease
of unknown cause
• Begins 40-50 years of age, more common in
women
• Signs and symptoms include joint pain and
swelling (usually bilateral), anemia,
osteoporosis, muscle weakness, and
cardiovascular problems
•RA begins with synovitis of the affected joint
• Inflammatory blood cells migrate to the joint,
release inflammatory chemicals, cartilage erodes,
scar tissue forms, bone ends connect.
•Treatment: aspirin, long-term use of antibiotics,
and physical therapy; anti-inflammatory drugs
or immunosuppressants; new biological
response modifier drugs neutralize inflammatory
chemicals
Clinical Forms of Chronic Arthritis
3. Gouty Arthritis
• Inflammation of joints is
caused by a deposition of
urate crystals from the
blood in joints and soft
tissues, followed by
inflammation
• Typically affects the joint at
the base of the great toe
• Can usually be controlled
with diet: drugs, plenty of
water, less red meat,
avoidance of alcohol
• More common in men
• In untreated gouty arthritis,
the bone ends fuse
Joints (Articulations)
• Functions of joints
• Classifying Joints: Functional or
Structural
• Naming Movements of Bones Around
Joints
• Types of Joints Based on Movement
• Selected Key Joints: Shoulder, Elbow,
Hip, Knee
• Joint Injuries
• Chronic Joint Conditions: Arthritis