A&P lecture Joints part 2

Largest, most complex joint in the body

3 Joints surrrounded by a single cavity

At least 12 associated bursae

• Joint capsule reinforced by muscle tendons
• -e.g. quadriceps and semimembranosus tendons

Joint capsule is thin and absent anteriorly

• 1. Femoropatellar Joint
• -Plane Joint
• -allowing gliding motion during knee flexion

• 2. & 3. Later and Medial tibiofemeral joints
• -between femoral condyles and the c-shaped later and medial menisci (semilunar cartilages)of the tibia
• -allow flexion, extension, and some rotation when knee is partly flexed

• Anteriorly, the quadriceps tendon gives rise to :
• -lateral and medial patellar retinacula
• -pattelar ligament

• Capsular and extracapsular ligaments:
• -help prevent hyperextension

• Intracapsular ligaments
• -anterior and posterior cruciate ligamens
• -prevent anterios-posterior displacement
• -reside outside the synovial cavity

Ball and socket Joint: head of humerus and glenoid fodda of ther scapula

Stability is sacrificed for greater range of movement

• 1. Coracohumeral ligament
• -only strong thickening of capsule
• -helps support the weight of the upper limb
• -rim of fibrocartilage in geloid cavitity called glenoid labrum: provides little stability

2. 3 glenohumeral ligaments- somewhat weak anterior reinforcements

• 1. Tendon of the long head of biceps: "super stabilizer"
• -travels through the intertubercular grooce
• - secures the humerus to the glenoid cavity

• 2. Four rotator cuff tendons encircle the shoulder joint
• A. Subscapularis
• B. Supraspinatus
• C. Intraspinatus
• D. Teres Minor

-Radius and ulna articulate with the humerus

-Hinge Joint formed mainly by trochlear notch of ulna and trochlea of humerus

-Flexion and extension only

Anular ligament- sounds the head of radius

• Two capsular ligaments restrict side-to-side movement:
• 1. Ulnar collateral ligament
• 2. Radial collateral ligament

-Ball and scoket joint

-Head of femur articulates with the acetabulum

-Good range of motion, but minited by deep scoket

-Acetabular labrun- enhances depth of socket and stabilizes

• 3 "Screw" a person's leg in straight when they stand
• Iliofemoral ligament
• Pubofemoral ligament
• Ischiofemoral Ligament

• Ligamentum Teres:
• -contains an artery that helps supply the head of the femur

The ligament is stretched or torn

partial tear slowly repair themselves (avascular)

Complete ruptures require prompt surgical repair

Due to compression and shear stress

Fragments (loose bodies) many cause joint to lock or bind

Cartilage rarely repairs itself (avascular)

Repaired with arthroscopic surgery

occur when bones are forced out of alignment

accompanies by sprains, inflammation, and joint immobilization

caused by serious falls or playing sports

Sublaxation: partial dislocation

• Bursitis
• -an inflamation of the bursa, usually cause by a blow or friction
• -treated with rest and ice; if severe then anti-inflammatory drugs

• Tendonitis
• -inflammation of tendon sheaths typically caused by overuse
• -symptons and treatment similar to bursitis

Over 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 the joint

Acute forms: caused by bacteria, treated with antibiotics

Chronic Forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis

-Common, irreversible, degenerative (wear and tear) arthritis

-85% of all Americans develops 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

-Chronic, inflammatory, autoimune disease of unknown cause

-Usually arises between age 40-50, but may occur at any age ; affects 3x as many women as men

-Sign and Symptoms: joint pain and swelling (usually bilateral), anemia, osetoporosis, muscle weakness, and cardiovascular problems

-RA begins with synovitis of the affected joint

-Inflammatory blood cells migrate to the joint, release inflammatory chemicals

-Inflamed synovial membrane thickens into pannys

-Pannus Erodes cartilage, scar tissue forms, articulating bone ends connect (ankylosis)

-Conservative therapy: aprin, long-term use of anti-biotics, and physcial therapy

-Progressive treatment: anti-inflammatory drugs or immunosuppressants

New Biological response modifeier drugs neutralize inflammatory checmicals

Deposition of uric acid crystals in joints and soft tissues, followed by inflammation

More common in men (estrogen increases uric acid excretion)

Typically effects the joint at the base of the great toe

In untreated gouty arthritis, the bone ends fuse to immobilize the joint

Treatment: drugs, planty of water, avoidance of alcohol

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: anti-biotics

Embryonic Week 8: synovial joints resemble adult joints

• Growing up and Adulthood:
• A Joints size, shape, and flexibility are modified by use

• Advancing years takes a toll on joints
• -Ligaments and tendons shorten and weaken
• -intervertebal discs become more likely to herniate
• -most peple in their 70s have some degree of OA

• Exercise that coaxes joints through their full range of motion is key to postponing joint problems
• -pool exercises are great because you get full motion without the weight