Chapter8 Flashcards
- synathroses_ —immovable
- amphiarthroses —slightly movable
- diarthroses —freely movable
functional classification of joints
- fibrous
- Cartilaginous
- synovial
strutural classifications of joints
- Bones joined by dense fibrous connective tissue
- No joint cavity
- Most are synathrotic (immovable)
Three types:
- Sutures
- syndesmoses_
- gomphoses
fibrous joints
- Rigid, interlocking joints containing short connective_ tissue fibers
- Allow for growth during youth
- In middle age, sutures ossify and are called synostoses
fibrous joints :sutures
- Bones connected by ligaments (bands of fibrous tissue)
- movement varies from immovable to slightly movable
Examples:
- synarthrotic distal tibiofibular joint
- diarthrotic interosseous connection between radius and ulna
Fibrous Joints: Syndesmoses
- Peg-in-socket joints of teeth in alveolar sockets
- Fibrous connection is the periodontal ligament
Fibrous Joints: Gomphoses
- Bones united by cartilage
- No joint_ cavity
Two types:
- Synchondroses
- Symphyses
Cartilaginous Joints
A bar or plate of hyaline cartilage unites the bones
All are synarthrotic
[ex. joint btw first rib and sternum]
Cartilaginous Joints: Synchondroses
- hyaline cartilage covers the articulating surfaces and is fused to an intervening pad of fibrocartilage
- strong, flexible amphiarthroses
[Ex.pubic symphysis]
Cartilaginous Joints: Symphyses
- All are diarthrotic
- Include all limb joints; most joints of the body
Features:
- articular cartilage:hyaline cartilage
- joint(synovial)cavity: small potential space
- articular(joint) capsule:
- outer fibrous capsule of dense irregular connective tissue
- inner synovial membrane of loose connective tissue
synovial joints
- capsular(intrinsic)—part of the fibrous capsule
- Extracapsular—outside the capsule
- Intracapsular—deep to capsule; covered by synovial membrane
in Synovial Joints the Three possible types of reinforcing ligaments:
components of synovial joint
- ligament
- joint cavity containing synovial fluid
- articular capsul with fibrous layer and synovial membrane
- periosteum
- flattened, fibrous sacs lined with synovial membranes
- Contain synovial fluid
- Commonly act as “ball bearings” where ligaments , muscles, skin, tendons , or bones rub together
bursae
Elongated bursa that wraps completely around a tendon
tendon sheath (friction reducing structure of synovial joint)
- Shapes of articular surfaces (minor role)
- Ligament number and location (limited role)
- Muscle tone , which keeps tendons that cross the joint taut_
- Extremely important in reinforcing shoulder and knee joints and arches of the foot
Stabilizing Factors at Synovial Joints
- Muscle attachments across a joint:
- origin_—attachment to the immovable bone
- insertion_—attachment to the movable bone
- Muscle contraction causes the insertion to move toward the origin
- movements occur along transverse, frontal, or sagittal planes
synovial joints: Movement
- nonaxial_—slipping movements only (tarsals)
- Uniaxial —movement in one plane
- biaxial—movement in two planes
- Multiaxial —movement in or around all three planes
Synovial Joints: Range of Motion
occurs when one flat, orn early flat, bone surface slips over another (back and forth and side to side without rotation)
Ex. intercarpal joints, btw articular processes of vertebrae
gliding
increase or decrease the angle btw 2 bones
angular movements
- flexion-decrease angle
- extension- increase angle
- hyperextension
- abduction- moving toward body midline
- adduction- moving away from body
- circumduction- moving a limb describing cone in space
- turning of a bone around its own long axis
- only movement allowed btw first 2 cervical vertebraeand common at hip and shoulder joints
rotation
- supination, pronation
- Dorsiflexion, plantar flexion of the foot
- inversion, eversion
- Protraction, retraction_
- elevation, depression
- opposition
special movments
turing backward/ turning forward
[ex. rotating forearm laterally so palm face anteriorly]
supination/pronation
lifting and pointing movements of the foot at the ankle
dorsiflexion and plantar flexion
special movements of the foot where sole of the foot turns medially or laterally
inversion/ eversion
lifting a body part superiorly or moving the elevated part inferiorly
elevation/ depression
ex. during chewing the mandible
- nonaxial
- Hinge
- pivot
- Condyloid
- saddle
- Ball and socket
6 types of synovial joints, based on articular surfaces
- nonaxial joints
- Flat articular surfaces
- Short gliding movements
ex. intercarpal joint (nonaxial movement)
plane joints
- uniaxial joints
- Motion along a single plane
- flexion and extension only
ex. elbow joint
hinge joints
- rounded end of one bone conforms to a “sleeve,” or ring of another bone
- uniaxial movement only
pivot joints
- biaxial joints
- Both articular surfaces are oval
- Permit all angular movements
ex. metacarpophalangeal joint, wrist joints
condyloid joints
- biaxial
- Allow greater freedom of movement than condyloid joints
- Each articular surface has both concave and convex areas
ex. carpometacarpal joint of thumb
saddle joint
- multiaxial joints
- The most freely moving synovial joints
ex.shoulder joint
ball and socket joint
- Largest, most complex joint of body
- Three joints surrounded by a single joint cavity:
- Femoropatellar joint:
- plane joint
- Allows gliding motion during knee flexion
- Lateral and medial tibiofemoral joints between the femoral condyles and the C-shaped lateral and medial menisci (semilunar cartilages) of the tibia
- Allow flexion , extension , and some rotation when knee is partly flexed
knee joint
tight fit; better flow of fluid around articular surfaces
Purpose of menisci
- At least 12 associated bursae
- capsule is reinforced by muscle tendons:
- E.g., quadriceps and muscle_ tendons
- Joint capsule is thin and absent anteriorly
- Anteriorly, the quadriceps tendon gives rise to:
- Lateral and medial patellar retinacula
- Patellar ligament
- Capsular and extracapsular ligaments
- Help prevent hyperextension
- Intracapsular ligaments:
- Anterior and posterior _cruciate ligaments
- Prevent anterior-posterior displacement
knee joint
- fibular/tibial collateral ligaments prevent lateral/medial rotation when knee extenses
- anterior/posterior cruicial ligament prevents forward sliding of the tibia and femur and checks hyperextenstion/backward displacement of the knee
- menisci prevents side to side rocking of the femur on the tibia and asorb shock transmitted to the knee
Extracapsular ligaments of knee
- Ball-and-socket joint
- Head of the femur articulates with the acetabulum
- Good range of motion , but limited by the deep socket
- acetebelar labrum—enhances depth of socket
hip(coxal) joint
- illiofemoral ligament-strong v shaped ligament anteriorly
- Pubofemoral ligament- trangular thickening of teh inferior part of the capsule
- ischiofemoral ligament-spiraling posterior ligament and “screw: into acetabulum when stood straight
- ligamentum teres-flate intracapsular band that runs from femur head to lower lip of the acetabulum containing artery helping supply head of femur
reinforcing ligaments of hip joint
- The ligaments are stretched or torn
- partial_ tears slowly repair themselves
- Complete ruptures require prompt surgical_ repair
sprains
- Due to compression and shear stress
- fragments may cause joint to lock or bind
- Cartilage rarely repairs itself
- Repaired with _arthroscopic_ surgery
cartilage tears
- Dislocations (_luxations )
- Occur when bones are forced out of alignment
- Accompanied by sprains , inflammation, and joint immobililization
- Caused by serious falls or playing sports
- Subluxation—partial dislocation of a joint
common joint injuries
- An inflammation of a bursa , usually caused by a blow or friction
- Treated with rest and ice and, if severe, antinflammatory drugs
bursitis
- inflmammation of _tendons_ sheaths typically caused by overuse
- symptions and treatment similar to bursitis
tendonitis
