lecture 7 Flashcards
joints and articulations
what are the types of joints?
fibrous joints, cartilaginous joints, synovial joints
how are joints classified?
classified based on structure
what are fibrous joints?
bones held together by fibrous tissue with no joint cavity
what are the different types of fibrous joints?
sutures, syndesmoses, gomphoses
how would you define sutures that stem from fibrous joints?
non mobile joints found in the skull
how would you define syndesmoses that stem from fibrous joints?
fibrous joint in which bones are connected by ligaments
ex. distal end of tibia & fibula, radius and ulna
how would you define gomphoses that stem from fibrous joints?
joint of the tooth and its socket
what are cartilaginous joints?
bones joined together by hyaline cartilage with no joint cavity
name the different types of cartilaginous joints?
synchondroses, symphyses
what are synchondroses of the cartilaginous joints?-
bones jointed by a cartilaginous plate
what do the synchondroses do? example?
source of growth, usually ossified after puberty; ex. joint between first rib and manubrium, epiphyseal plate of long bones
what is the symphyses?
pad between bones composed of fibrocartilage sandwiched between hyaline cartilage
what do the symphyses do? example?
allow for movement and acts as a shock absorber; ex. intervertebral joints and the pubic symphysis
what the synovial joints?
articulating bones separated by fluid filled joint cavity
whats the general structure of the synovial joint?
articular cartilage, joint cavity and articular capsule, synovial membrane, synovial fluid, reinforcing ligaments
what are the different types of reinforcing ligaments?
intrinsic, extracapsular, intracapsular
what is the intrinsic reinforcing ligament?
part of the fibrous capsule
what is the extra capsular reinforcing ligament?
found on the outside capsule
what is the intracapsular reinforcing ligament?
just deep to capsule
what is significant about the synovial joint?
it prevents friction on adjacent structures.
how do the synovial joints prevent friction on adjacent structures?
bursae and tendon sheaths
what is bursae?
flattened sacs containing synovial fluid, common where bones, tendons and ligaments rub together.
what is false bursae?
develop at sites of excessive motion
what is bursitis?
inflammation of a bursa from overuse, injury, infection, continual microtrauma, etc.
what are tendon sheaths?
elongated bursae that wraps around a tendon subjected to friction
what are factors influencing synovial joint stability?
articular surface, ligaments, muscle tone
how does articular surface influence synovial joint stability? name example?
it determines range of motion moreso than stability, an example would be deep ball and socket like the hip joint that provides much stability
how does the ligament influence synovial joint stability? name example?
they function to direct bone movement and prevent excessive range and if other stabilizing factors are inadequate then the ligaments stretch and so they cannot return to original length and the joint that relies mainly on ligaments for stabilization will not be very strong
how does muscle tone influence synovial joint stability? name example?
tendons crossing the joint are important in stabilizing the joint, increased muscle tone keeps tendon more taut, important in shoulder and knee joints, increased when we work out and provides more stability for the joint
what types of movements are provided by the synovial joint?
flexion, extension, hyperextension, abduction, adduction, rotation and circumduction moving arms in circle like motion
what are some specialized movements provided by the synovial joint?
inversion, eversion, dorsiflexion, plantar flexion, supination, pronation, elevation, depression, protraction, and retraction
what are the different types of synovial joints?
hinge, pivot, saddle, plane or gliding, ball and socket, ellipsoid
define and name an example of a hinge joint?
allows flexion and extension (ex. elbow, knee, ankle)
define and name an example of a pivot joint?
allows rotation (ex. atlas and axis; proximal radius and ulna)
define and name an example of a saddle joint?
convex surface (saddle) fits into concave surface (ex. trapezius and metacarpal of thumb)
define and name an example of a plane or gliding joint?
articulations on flat surfaces»_space; side-to-side movements (ex. tarsals; carpals)
define and name an example of a ball and socket joint?
allows movement in three planes (ex. shoulder; hip)
define and name an example of a ellipsoid joint?
restricted saddle joint (ex. wrist)
what is the hip?
synovial ball and socket joint
what is the hip comprised of?
articular capsule, ligamentum capitus or round ligament, acetabular labrum, lunate surface of the acetabulum
what is the articular capsule?
extends from neck of femur to rim of acetabulum with four major intrinsic ligaments
*what is the ligamentum capitus or round ligament?
intracapsular ligament from fovea capitus to transverse ligament
what is the acetabular labrum?
ring of fibrocartilage that deepens acetabular cavity
what comprises the acetabular labrum?
transverse ligament and note that is enhanced such that half of the femur head fit is embedded within the acetabulum
what does the lunate surface of the acetabulum equate too?
articular surface
what is the purpose of the synovial membrane in the hip?
line all internal surfaces other than articular cartilages
what is the purpose of the fat pad in the acetabular fossa deep to the synovial membrane?
provides filler + cushioning
where are hip fractures most common?
most commonly occur at neck of femur from osteoporosis or traumatic injury and this affects the proximity of medial circumflex artery can lead to aseptic vascular necrosis
what are the knee joints comprised?
patellofemoral joint and the tibiofemoral joint
what is the patellofemoral joint?
a synovial gliding joint
what is the tibiofemoral joint?
a synovial hinge joint
how does the shape of the synovial capsule affect the knee joint?
it attaches to edges of patella and periphery of menisci, it also envelopes the cruciate ligament and infrapateller fat pad both not located within the capsule
the suprapatellar bursa is not an extension of the joint capsule, T/F?
F, it is an extension of the joint capsule
what do the intra-articular ligaments do?
they limit the rotation of the knee
what are the intra-articular ligaments?
Anterior cruciate ligament, posterior cruciate ligament and the medial/lateral menisci
what is the fibular and tibial collateral ligaments?
taut when knee extended but slack during flexion to allow rotation of the knee
what is the oblique popliteal ligament?
expansion of the tendon of the semimembranosus that strengthens posterior portion of capsule
what is the arcuate popliteal ligament?
Y-shaped ligament from head of the fibula to intercondylar area of tibia and lateral condyle of femur
what are the important bursae?
prepatellar bursa,infrapatellar bursa (deep and superficial), suprapatellar bursa
what is the prepatellar bursa?
allows movement of the skin over the underlying patella
what is prepatellar bursa also known as?
housemaid’s bursitis
what is the infrapatellar bursa (deep and superficial)?
allow for movement of the patellar ligament over the tibia
what is infra patellar also known as?
gardener’s or clergyman’s bursitis
what is suprapatellar bursa?
allows for movement of the quadriceps tendon over the distal end of the femur
what is suprapatellar bursa also known as?
suprapatellar bursitis
what other clinical cases can be discussed with an injured knee joint?
Baker’s cyst
what is Baker’s Cyst?
excess fluid in synovial cavity causes capsule to herniate posteriorly and typically associated with arthritis any form or traumatic injury
