Lecture: Chapter 08 Flashcards
JOINTS
a.k.a. “Articulations;” where two or more bones meet.
FUNCTIONS:
1) Give the skeleton mobility
2) Hold bones together, sometimes playing a protective role in the process
CLASSIFICATION OF JOINTS
classified by STRUCTURE & FUNCTION
STRUCTURAL CLASSIFICATIONS
1) Fibrous joints
2) Cartilaginous joints
3) Synovial joints
FUNCTIONAL CLASSIFICATIONS
1) Synarthroses - immovable joints (axial)
2) Amphiarthroses - slightly moveable joints (axial)
3) Diarthroses - freely moveable joints (mostly appendicular)
-FIBROUS JOINTS-
Joined by fibrous tissue; no joint cavity. Three types: sutures, syndesmoses, gomphoses.
SUTURES
fibrous joint
only in SKULL; Function: absorb mechanical stress; Major skull sutures: Coronal (frontal/parietal), Sagittal (both parietals), Squamous (temporal/parietal), Lambdoid (occipital/parietal)
SYNDESMOSES
fibrous joint
bones connected by a ligament; i.e. tibia and fibula
GOMPHOSES
fibrous joint
peg-in-socket; i.e. tooth in jaw
-CARTILAGINOUS JOINTS-
Bones joined by cartilage; TWO types: 1) Synchondroses, 2) Symphyses
SYNCHONDROSES
cartilaginous joint
hyaline cartilage joins the bones; e.g. coastal cartilage of the first ribs and sternum
SYMPHYSES
cartilaginous joint
fibrocartilage plate between bones; e.g. pubic symphysis & intervertebral joints
-SYNOVIAL JOINTS-
Bones are separated by fluid-filled cavity; diarthroses (freely moveable); Most joints, especially in limbs.
EXAMPLES OF SYNOVIAL JOINTS
1) Shoulder (clavicle, scapula): ball-in-socket, multiaxial plane
2) Hip (ilium, ischium, pubis): ball-in-socket, multiaxial
3) Elbow (humerus, radius, ulna) hinged
4) Thumb: saddle joint; biaxial.
BURSAE
little lubricating sacs that also act as shock absorbers; reduce friction between structures (bone & tendon, tendon & tendon etc.)
TENDON SHEATH
basically a long bursa that wraps around a tendon
MOVEMENTS OF SYNOVIAL JOINTS
All muscles are attached to bones in at least two places. The ORIGIN is more proximal; the INSERTION is more distal and across a joint. When a muscle contracts, it pulls the insertion toward the origin to move the bone.
GLIDING MOVEMENT
a.k.a. “Translation;” bone surfaces slide past one another; e.g. between rows of carpal (wrist) bones.
-ANGULAR MOVEMENTS-
changes the angle between two bones; (different types listed on following cards)
FLEXION
bending usually in sagittal plane (going forward - touching toes); * decreasing angle between bones; chin to chest
EXTENSION
opposite of flexion; straightening (rather than bending)
DORSIFLEXION
of foot
toes bend toward shin
PLANTAR FLEXION
of foot
pointed toes
ADDUCTION
moving toward the midline
ABDUCTION
moving away from the midline
CIRCUMDUCTION
moving in a circle; flexion+abduction+extension+adduction
ROTATION
C1(Atlas)-Yes motion; C2(Axis)-No motion.
turning a bone around its own long axis; Cervical 1 & 2 are only vertebrae to do this; hip and shoulder also rotate.
PRONATION
“turning forward;” distal end of radius moves across ulna; happens in horizontal plane.
SUPINATION
“turning backward;” radius and ulna are parallel; “more soup, please.”
INVERSION
ankle turns foot inward (pigeon toed)
EVERSION
ankle turns foot outward (fat person waddle)
PROTRACTION
moves chin out (up) in transverse plane
RETRACTION
moves chin in (down) toward chest
ELEVATION
move superiorly (shrugging shoulders)
DEPRESSION
move inferiorly (opening mouth)
OPPOSITION
touching tip of thumb to fingers
-TYPES OF SYNOVIAL JOINTS-
Plane, Hinge, Pivot, Condyloid, Saddle, Ball-in-Socket
see following cards
PLANE JOINTS
(non-axial movement) flat surfaces allow only gliding; EX: intercarpal/intertarsal joints & vertebral articular processes
HINGE JOINTS
(uniaxial) like a door hinge; movement in one plane; EX: 1) elbow (ulna & humerus), 2) ankle (tallus, fibula, tibia), 3) interphalangial joint of toe
PIVOT JOINTS
(uniaxial) rounded end of bone fits into “ring” at another bone; Ex: proximal radio ulnar joint (where leaves fit into table)
CONDYLOID JOINTS
(biaxial) oval articular surface fits into oval articular surface; Ex: radio carpa joints (wrists) and metacarpophalangeal joints (knuckles)
SADDLE JOINTS
(biaxial) saddle surface fits on saddle-like surface upside-down; Ex: carpometacarpal joint of thumb.
BALL-N-SOCKET
(multiaxial) round ball fits into cup-like socket; this type allows most range of motion; Ex: hip and shoulder
-INJURIES OF JOINTS-
see following cards
SPRAINS
ligaments around joint are stretched or torn; heals slowly; (ankle sprains occur most commonly from inversion)
CARTILAGE INJURIES
tearing the meniscus is the most common of this type; usually doesn’t heal well; can cause joint mice bites of cartilage that break off and interfere with joint movement. Usually repaired with arthroscopic surgery.
DISLOCATION
articular surfaces no longer line up. Common in falls in sports injuries. Fixed by reduction of dislocation.
SUBLUXATION
partial dislocation w/ partial contact between bone.
BURSITIS
inflammation of bursa; usually caused by trauma or friction
TENDONITIS
inflammation of tendon, usually caused by overuse (tennis elbow)
-ARTHRITIS-
One hundred different types. Early symptoms: 1)pain, 2)stiffness, 3) swelling. Chronic forms include osteo-, rheumatoid, and gouty arthritis.
OSTEOARTHRITIS
MOST COMMON chronic arthritis; more women affected than men, but 85% of all Americans get it; non-inflammatory; WEIGHT-BEARING JOINTS are most affected (cervical/lumbar spine, fingers knuckles, knees, & hips); long term degenerative arthritis destroys joint cartilage over time; rarely crippling but can be if hips or knees are involved
RHEUMATOID ARTHRITIS
chronic INFLAMMATORY DISORDER with insidious onset; usually arises between age 30 and 50 but can occur at any age; affects 3 times as many women than men; AUTOIMMUNE DISEASE involving severe inflammation of the joints (body’s immune system attacks its own tissues); joint tenderness and stiffness are early symptoms; BILATERAL AFFLICTION particularly of the SMALL JOINTS (fingers, wrists, ankles, feet)
GOUTY ARTHRITIS
caused by deposits of needle shaped uric crystals in the joints from excessively high blood levels of uric acid that should be eliminated by the kidneys (a failure of purine (protein) metabolism); urate salts in soft joint tissue; typically affects one joint often at the base of the big toe; more common in men b/c of naturally higher levels of uric acid; avoid alcohol excess and foods high in purine (cheese., sardines); if untreated articulating bone ends can fuse and immobilize the joint
LYME’S DISEASE
inflammatory disease caused by spirochete bacteria transmitted by ticks that live on mice and deer; results in joint pain (arthritis most commonly in knees); symptoms include skin rash, flu-like symptoms, and foggy thinking; if untreated neurological disorders and irregular heartbeats may ensue; treatment: antibiotics.
