joints Flashcards
What are joints?
articulations; where 2 bones come together
What do joints do?
hold bones together securely; give the skeleton mobility
What is function?
amount of movement allowed by the joint; range of motion (ROM)
What is synarthroses?
immovable
What is amphiarthroses?
slightly movable
What is diarthroses?
freely movable
What are fibrous joints?
bones held together by fibrous connective tissue
What are characteristics of fibrous joints?
lack a synovial cavity; most are synarthrotic; some are amphiarthrotic
What are cartilaginous joints?
bone ends connected by cartilage; lack a synovial cavity
What are examples of cartilaginous joints?
pubic symphysis & intervertebral discs (amphiarthrotic); hyaline cartilage epiphyseal plates & joints between ribs and sternum (synarthrotic)
What are examples of fibrous joints?
sutures of the skull (synarthrotic); syndesmosis: the connecting fibers are longer than the sutures and have more “give” (amphiarthrotic)
What are synovial joints?
bone ends are separated by a joint cavity containing synovial fluid; all are diarthrotic
What are examples of synovial joints?
knee, shoulder, elbow, hip, fingers
What are features of synovial joints?
articular cartilage, articular capsule, joint cavity, & synovial fluid
What is the articular cartilage?
hyaline cartilage covers the ends of bones forming the joint
What is the articular capsule?
capsule that surrounds the joint; lined with a smooth synovial membrane
What is the joint cavity?
space inside the capsule; contains lubricating synovial fluid
What is the synovial fluid?
clear fluid with a consistency of molasses; lubricates, distributes nutrients, & absorbs shock
What are cartilage & fat pads?
lie between opposing articular surfaces
What is a meniscus?
pad of cartilage between opposing bones with a synovial joint
What are fat pads?
masses of adipose tissue that protect the cartilage and act as packing material for the joint
What are reinforcing ligaments & tendons?
support, strengthen, & reinforce synovial joints
What is a bursa?
flattened sacs filled with synovial fluid; common where things rub together; they reduce friction & absorb shock
What is a tendon sheath?
an elongated/tubular bursa that wraps like a hot dog bun around a tendon that is subject to friction; where tendons cross bony surfaces
What are the types of synovial joints based on shape?
plane “gliding” joint, hinge joint, condyloid (ellipsoid) joint, saddle joint, pivot joint, & ball-and-socket joint
What are characteristics of plane “gliding” joints?
articular surface is basically flat; only short gliding movements allowed; nonaxial
What are examples of plane “gliding” joints?
intercarpal joints (wrist), SI joint, AC joint
What are characteristics of hinge joints?
rounded process of one bone fits into a trough-shaped surface of another; movement in one plane is allowed (like a door hinge); uniaxial/monoaxial
What are examples of hinge joints?
elbow, knee, ankle, interphalangeal
What are characteristics of condyloid (ellipsoid) joints?
“knuckle-like” oval condyle of one bone fits into an oval depression of another; biaxial
What are examples of condyloid (ellipsoid) joints?
metacarpophalangeal joints (knuckles)
What are characteristics of saddle joints?
articular surface is saddle-shaped; biaxial
What are examples of saddle joints?
carpometacarpal joint of the thumb
What are characteristics of pivot joints?
rounded end of one bone fits into a shallow depression of another; uniaxial/monoaxial
What are examples of pivot joints?
proximal radioulnar joint, the atlas/axis of spine
What are characteristics of ball-and-socket joints?
ball-shaped head of one bone fits into a cup-like depression of another; multiaxial; mostly diarthrotic
What are examples of ball-and-socket joints?
shoulder & hip
What are the types of ligaments of the knee?
cruciate ligaments, collateral ligaments, meniscus, & patellar ligament
What are the cruciate ligaments?
anterior cruciate ligament (ACL) & posterior cruciate ligament (PCL)
What are characteristics of cruciate ligaments?
found in the center of the knee joint; provide stability to the knee
What are the collateral ligaments?
medial (tibial) collateral ligament (MCL) & lateral (fibular) collateral ligament (LCL)
What does the MCL do?
attaches the femur to the tibia on the inner side of the knee
What does the LCL do?
attaches the femur to the fibula on the outer side of the knee
What is the meniscus?
medial & lateral meniscus; provide shock absorption within the knee joint
What is the patellar ligament?
quadriceps tendon; attaches patella to tibia (inserts on tibial tuberosity)
What is the terrible triad?
involves the ACL, MCL, & medial meniscus
What are the ligaments of the ankle on the lateral side?
anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), & calcaneofibular ligament (CFL)
What are the ligaments of the ankle on the medial side?
deltoid ligaments
What are the ligaments of the ankle attaching the tibia to the fibula?
anterior inferior tibiofibular ligament & posterior inferior tibiofibular ligament
What are the ligaments of the shoulder?
acromioclavicular (AC) ligament, coracoclavicular ligaments (2), & coracoacromial ligament
What is the AC ligament?
attaches acromion process to the clavicle
What are the coracoclavicular ligaments?
attach coracoid process to the clavicle
What is the coracoacromial ligament?
attaches coracoid process to acromion process
What are the inflammatory disorders of joints?
bursitis, osgood-schlatter, arthritis, & gout
What is bursitis?
inflammation of a bursa (synovial membrane); ex.= “water on the knee”
What is osgood-schlatter?
inflammation at the point where patellar tendon attaches to tibial tuberosity
What are characteristics of osgood-schlatter?
common in active adolescents who are still growing; repetitive stress from the patellar tendon pulling on the bone causes inflammation over the growth plate of the tibia
What is arthritis?
inflammation of a joint
What are characteristics of osteoarthritis?
most common form; affects the aged; caused by wear & tear; softening, fraying, & breakdown of articular cartilage; most affected are the fingers, cervical & lumbar joints, and knee & hip joints
What are characteristics of rheumatoid arthritis?
chronic inflammatory disorder; autoimmune disease; articular cartilage is destroyed & scar tissue forms, ossifies, and connects the bone ends permanently & usually deformed
What are characteristics of gout?
uric acid accumulates in the blood and can become deposited as needle-like crystals in the joint; if untreated, the bone ends may fuse and become immobile
What are the 2 types of arthritis?
osteoarthritis and rheumatoid arthritis
What is the origin?
the stationary, or less movable, attachment of a muscle
What is the insertion?
the movable attachment of a muscle
When does movement occur?
when muscles contract across diarthrotic synovial joints
What happens when a muscle contracts?
the insertion moves toward the origin
What is a goniometer?
measures angles of joints/ROM
What are the types of movements at joints?
flexion, extension, rotation, & circumduction
What are the movements that occur only with the limbs?
abduction & adduction
What are the movements that occur in the forearm?
pronation & supination
What are the movements of the foot & ankle?
inversion, eversion, dorsiflexion, & plantarflexion
What is flexion?
movement that decreases the angle of a joint; brings 2 bones closer together; bending
What is extension?
movement that increases the angle of a joint; increases the distance between 2 bones; straightening
What is hyperextension?
when the angle between 2 joints is greater than 180°
What is rotation?
movement of a bone around its longitudinal axis
What is circumduction?
combination of flexion, extension, abduction, & adduction; ex.= arm circles
What is abduction?
movement of a limb away from the midline; also includes fanning of the fingers/toes
What is adduction?
movement of a limb toward the midline
What is pronation?
movement of the palm of the hand from an upward-facing position to a downward-facing position
What is supination?
movement of the palm from a downward-facing position to an upward-facing position
What is inversion?
turning the sole of the foot inward
What is eversion?
turning the sole of the foot outward
What is dorsiflexion?
moving the toes toward the shin
What is plantarflexion?
pointing toes
What is protraction?
sticking out; protruding
What is retraction?
drawing something back in
What is elevation?
lifting up
What is depression?
pressing down