Chapter 8: Joints Flashcards
Joints
articulations; sites where 2 or more bones meet; weakest part of the skeleton; function to hold skeleton together and allow mobility
What are the functional classification of joints?
based on amount of movement allows at joing; synarthrosis, amphiarthrosis, diarthrosis
Synarthrosis
immoveable joint
Amphiarthrosis
slightly moveable joint
Diathrosis
freely moveable joint
What are the structural classifications of joints?
based on material binding 2 bones together and whether or not a joint cavity is present; fibrous, cartilaginous, synovial
Fibrous Joints
parallel bones joined by collagen fibers of connective tissue; no joint cavity; ex) sutures (synarthrotic), inferiortibiofibular ligament (amphiarthrotic), interossesous membranes (amphiarthrotic)
Cartilaginous Joints
bones joined by cartilage (hyaline or fibrocartilage); no joint cavity; ex) epiphyseal plate (synarthrotic), pubic symphysis (amphiathrotic), intervetebral discs (amphiarthrotic)
Synovial Joints
most abundant; bones separated by fluid filled cavity; other joints do not have fluid; all are diarthrosis (freely moving); almost all of the bones in the limbs are synovial
Features of Synovial JOints
articular cartilage, articular joint capsule, joint cavity, synovial fluid, ligaments, nerves and blood vessels
Articular Joint Capsule
outer fibrous layer (dense irregular CT) and is continous with the periosteum of bones; inner synovial membrane (loose CT) is continuous with articular cartilage; secretes synovial fluid
Joint Cavity
potential space; contains synovial fluid
Synovial Fluid
viscous fluid within joint cavity and articular cartilage; acts as a lubricate to decrease friction; nourishes articular cartilage
Ligaments
thick bands of dense irregular tissue that reinforce and strengthen joint; connects two bones; avascular and does not heal well
Nerves and Blood Vessels
some nerves detect pain; most moniter joint position and stretch; blood vessels supply synovial membrane ( it needs fluid from blood to make synovial fluid)
Joints are stable when….
articular surfaces are large and fit closely together (sutures) or sockets are deep (acetabulum); ligaments are positioned to reinforce joint and prevent undesireable movement; there is adequate muscle tone which is tension in a relaxed muscle and is the most important stabilizing factor of most joints
Bursae
flattened fibrous sacs lined with synovial membrane; contain synovial fluid; occur where ligaments, muscles, skin, tendons, or bones rub against each other; functoin to reduce friction during joint activity
Tendon Sheaths
elongated fluid filled sacs that wrap around tendons subject to friction; occur where several tendons are crowded together; function to reduce friction during joint activity
What are the different categories of movement at synovial joints?
gliding movements, angular movements, rotational movement, and special movements
Gliding Movements
sliding the flat surface of 2 bones across each other; ex) intercarpal, intertarsal, intervertebral joints
What are the different angular movements?
increasing or decreasing the angle between two bones; flexion, extension, hyperextension, abduction, adduction, circumduction
Flexion
decreasing the angle between two bones along the sagittal plane; ex) bending the head forwards
Extension
increasing angle between 2 bones along sagittal plane; ex) straightening flexed neck
Hyperextension
increasing angle of joint beyond anatomical position
Abduction
moving a limb away from the midline of body along frontal plane; ex) raising arm to the side
Adduction
moving a limb toward midline of body along frontal plane; ex) lowering arm to the side
Circumduction
moving a limb or fongers so that the distal end moves in a circle; ex) shoulder, hip joint, finger
Rotational Movement
turning a bone around its own long axis; ex) rotation of atlas around dens of axis, lateral rotation of thigh and medial rotation of thigh
What are the special movements of joints?
supination/pronation, dorsiflexion/plantar flexion, inversion/eversion; protraction/retraction; elevation/depression; opposition
Supination/Pronation
refer to movements of radius around the ulna; supination- radius and ulna are parallel, palms face anteriorly or superiorly; pronation- distal end of radius corsses over ulna, palm faces posteriorly or inferiorly
Dorsiflexion/Plantar Flexion
refers to the up/down movement of foot; dorsiflexion- lifting the foot at the ankle; plantar flexion- pointing the toes down
Inversion/Eversion
inversion- sole of foot turns medially; eversion- sole of the foot turns laterally
Protraction/Retraction
anterior/posterior movements in the transverse plane; protraction- anterior movements of mandible; retraction- posterior movements of mandible
Elevation/Depression
superior/inferior movements of a body part; elevation- superior movements of mandible or shoulder; depression- inferior movement of mandible or shoulder
Opposition
touching your thumb to tips of fingers
Non-Axial Movement
gliding movements only
Uniaxial Movement
movement in one plane
Biaxial Movement
movement in two planes
Multiaxial Movement
movement in or around all three planes
Plane Joint
bones that are flat and can only glife; nonaxial; intervertebral , intercarpal, joints between vertebral articular surfaces
Hinge Joint
uniaxial; cylinder/trough between 2 bones like hinge of a door; elbow joints, interphalangeal joints (the joints that are only between the phalanges and metacarpal)
Pivot Joints
uniaxial; sleeve and axle; proximal radioulnar joint; atlantoaxial joint
Condylar Joint
biaxial movements; slightly concave surface coming into contact with convex surface; flexion/extension, adduction/abduction; metacarpophalangeal (knuckle joints), wrist joints
Saddle Joints
biaxial movement; looks like a saddle; adduction/abduction, flexion/extension; carpometacarpal joint of the thumb
Ball and Socket Joint
multiaxial movement; shoulder and hips joints; flexion/extension, adduction/abduction and rotation
Sprains
ligaments are stretched and torn; heal poorly because it is poorly vascularized; completely torn ligaments can be sewn back together or replaced with grafts of tendons
Dislocation
aka luxations; bones are forced out of alignment; treated by reduction (bone ends repositioned)
Cartilage Tears
most involve the knee meniscil treated with arthroscopic surgery
What are the inflammatory and degenerative conditions of the joints?
bursitis, tendonitis, arthritis, osteoarthritis , rheumatoid arthritis , gouty arthritis , lyme disease
Bursitis
inflammation of a bursa; usually caused by a blow or prolonged pressure; housemaids knee or students elbow; treatment: rest, ice and injection of anti inflammatory drugs
Tendonitis
inflammation of a tendon; usually caused by repetitve movement; tennis elbow (lateral epicondylitis) or golfers elbow (medial epicondylitis); treatment: rest, ice, bracing, and injection of antiinflammatory drugs
Arthritis
inflammatory or degenerative diseases that damage joints; most widespread, crippling disease in N. America; 1 in 5 are affected ; may be acute or chronic
Acute Arthritis
usually result from bacterial infection; treated with anitbiotics
Chronic Arthritis
long lasting; 3 common forms: osteoarthritis; rheumatoid arthritis; and gouty arthritis
Osetoarthritis
“wear and tear arthritis”; most common form of chronic arthritis; articular cartilage destroyed more rapidly than it is replaced; progression is slow and irreversible, but rarely crippling; joints are stiff in the mornings but lessens with activity; typically accompanied by crepitus (that weird popping sound ); more females affected than males
Rheumatoid Arthritis
most crippling form; autoimmune disease; usually arises between ages 30 and 50; more females than males affected; involves restriction of joint movement and extreme pain; usually bilateral; immunosuppressive drugs slow progression
Gouty Arthritis
tends to run in families (genetic); caused by high blood levels of uric acid that is deposited as sharp urate crystals in joints; first attack is usually affects the joint at base of big toe; more males affected than females; if left untreated bone ends fuse; patients advised to drink lots of water and avoid excess alcohol consumption
Lyme Disease
inflammatory disease caused by a spirochete bacterium; transmitted by ticks that live on deer or mice; hard to diagnose; symptoms may include: joint pain, flu-like symptoms, foggy thinking, and/or a skin rash
Synovial Membrane
inner layer of articular capsule; creates synovial fluid
