Chapter 8: Joints Flashcards
Articulation
Where 2 bones meet
What are functions of joints?
Give skeleton mobility and hold the skeleton together
Some allow extensive movement, some allow no movement
What are the general classifications of joints?
Functional and structural
Functional
How does it move?
Structural
What is it made of?
What are the functional classifications?
Synarthroses, amphiarthrosis, diarthroses
Describe synarthroses joints
Fixed, immovable, fibrous
What are some examples of synarthroses joints?
Sutures between skull bones
Describe amphiarthrosis joints
Slightly moveable, cartilaginous
What are some examples of amphiarthrosis joints?
Intervertebral discs
Describe diarthroses joints
Freely moveable, synovial joint
What is an example of diarthroses joints?
Found at ends of long bones
What are the structural classifications of joints?
Synovial, cartilaginous, fibrous
What are defining features of fibrous joints?
Articulated bones united by fibrous tissue
True or false: fibrous joints have a joint cavity
False
What are the 3 types of fibrous joints?
Suture, syndesmosis, gomphosis
Define suture joint (fibrous joint)
Joint held together w/ very short, interconnecting fibers, and bone edges interlock, found only in the skull
Describe suture joints (fibrous joint)
Closed, immovable sutures
Define syndesmosis joints (fibrous joint)
Joint held together by a ligament, fibrous tissue can vary in length, but is longer than in sutures
Describe syndesmosis joints (fibrous joint)
Bones connected by ligaments
Define gomphosis joints (fibrous joint)
“Peg in socket” fibrous joint, periodontal ligament holds tooth in socket
Describe gomphosis joints (fibrous joint)
Fibrous connection → periodontal ligament
What is an example of gomphosis joints?
“Peg-in-socket” joints (teeth in alveolar sockets)
what are the defining features of cartilaginous joints?
articulated bones united by cartilage
True or false: cartilaginous joints have a joint cavity
false
Describe a cartilaginous joint’s movement
limited movement, not highly movable
what are the two types of cartilaginous joints?
synchondroses and symphyses
What are synchondroses joints?
bones united by hyaline cartilage
What are symphyses joints?
fibrocartilage unites bones (in between articulate hyaline)
What are the defining features of synovial joints?
articulating bones are separated by fluid-filled joint cavity
Describe a synovial joint’s movement
diarthroses: freely moveable
what are the major characteristics of synovial joints?
have 6 general features
associated with bursae and tendon sheaths
stability is influenced by 3 factors
allow several types of movements
classified into 6 different types
What does hyaline cartilage do in synovial joints?
absorbs compression, prevents crushing of ends of bones
what is a synovial cavity?
space containing synovial fluid
what is the fibrous layer of the articular capsule?
a dense irregular connective tissue that provides strength to the joint
what is the synovial membrane?
loose connective tissue that secretes synovial fluid
what is synovial fluid?
secreted by the synovial membrane
viscous, slippery filtrate of plasma and hyaluronic acid
lubricates and nourishes articular cartilage
What are reinforcing ligaments?
dense, regular connective tissue
strengthens joint
found outside the joint cavity
what are the 3 types of reinforcing ligaments?
capsular, extracapsular, intracapsular
where is a capsular reinforcing ligament?
thickened part of fibrous layer
where is the extracapsular reinforcing ligament?
outside the capsule
where is the intracapsular reinforcing ligament?
deep to the capsule, covered by synovial membrane
what do nerves do in synovial joints?
detect pain, monitor joint position and stretch
true or false: synovial joints are highly vascularized
true
what are the accessory structures of synovial joints?
ligaments, tendons, muscles, meniscus, fat pad, bursae, and tendon sheaths
what are ligaments (in synovial joints)?
connect bone to bone
reinforce range of motion
what are tendons (in synovial joints)?
connect bone to muscle
limit range of motion, provide support
what are muscles (in synovial joints)?
stability and movement
what is the meniscus?
fibrocartilage pad
improves “fit” of bone ends
stabilizes joint
reduces wear and tear
what is the fat pad?
cushioning between fibrous layer of capsule and synovial membrane or bone
What is bursae?
reduces friction where ligaments, muscles, skin, tendons, or bone rub together
what are tendon sheaths?
elongated bursae wrapped completely around tendons subjected to friction
what affects the stability of a joint?
shape of articular surface
ligament number and location
muscle tone keeps tendons taut as they cross joints
how do joints help us move?
muscle pull on bones causing changes in the angle between 2 bones at the joint
what is an origin?
attached to immovable bone
what is an insertion?
attached to movable bone
true or false: the insertion moves toward the origin during a muscle contraction
true
where to movements occur?
transverse, frontal, or sagittal planes
what are the three types of movement?
gliding, angular movement, rotation
define gliding
one flat bone surface glides/slips over another similar surface
what are some examples of bones that glide?
intercarpal joints, intertarsal joints, between vertebrae articular processes
define angular movement
increase or decrease the angle between two bones
what is flexion?
decreases the angle of the joint
what is extension?
increase the angle of the joint
what is hyperextension?
movement beyond the anatomical position
what is abduction?
away from the midline
what is adduction?
toward the midline
what is circumduction?
involves flexion, abduction, extension, and adduction of limb
define rotation
turning of bone around its own axis, toward the midline or away from it
how do we classify synovial joints?
by direction and movement
what are the types of directions (synovial joints)?
nonaxial, uniaxial, biaxial, multiaxial
what are the types of movements (synovial joints)?
plane, hinge, pivot, saddle, condylar, ball & socket
nonaxial movement
slipping motion (no axis)
uniaxial movement
movement in one plane
biaxial movement
movement in 2 planes
multiaxial movement
movement in all 3 planes
what are the 4 synovial joints we need to know?
knee, shoulder, elbow, hip
characteristics on the knee
largest and most complex joint in the body
diarthroses, hinge, complicated
flexion, extension, limited rotation
single joint cavity, but three joints in one
femoropatellar
femur-patella
tibiofemoral
lateral and medial condyles of the femur each articulate with the tibia
tibia-fibula
where the tibia and fibula meet
structural components of the knee
articular capsule, menisci, ligaments, bursae, fat pads, knee joint can lock for standing
articular capsule
line, incomplete
menisci
cushion; allow charges in shape; provide lateral stability
ligaments
7, stabilize
bursae
reduce friction
fat pads
provides cushion
what do the capsular and extracapsular ligaments do?
help prevent hyperextension of knee
what do the fibular and tibial collateral ligaments do?
prevent rotation when knee is extended
what does the oblique popliteal ligament do?
stabilizes posterior knee joint
what does the arcuate popliteal ligament do?
reinforces joint capsule posteriorly
what are the intracapsular ligaments of the knee?
anterior crucial ligament (ACL)
posterior crucial ligament (PCL)
Anterior cruciate ligament (ACL)
prevents forward sliding of tibia and stops hyperextension of knee
posterior cruciate ligament (PCL)
prevents backward sliding of tibia and forward sliding femur
true or false: the knee is very susceptible to sports injuries
true
is the knee able to withstand vertical or horizontal force?
vertical
what are the 3 C’s that injuries occur to?
collateral ligaments, cruciate ligaments, cartilages
characteristic of the shoulder joint
diarthroses, ball and socket
articular capsule enclosing cavity is thin and loose
greatest range of motion
what motions can the should joint do?
flex, extend, abduct, adduct, rotate, circumduction
what are the 4 rotator cuff tendons?
subscapularis, supraspinatus, intraspinatus, teres minor
characteristics of the elbow joint
humeroulnar joint, diarthroses, hinge joint
what is the articulation of the elbow joint?
radius and ulna articulate with the humerus condyles
what makes the elbow joint extremely stable?
interlocking bones, thick articular capsule, strong ligaments, muscles stabilize
nursemaid’s elbow
dislocated radius
characteristics of the hip joint
diarthroses, ball and socket
bony socket
fibrocartilage pad covers acetabulum
sturdy
what motions does the hip joint do?
flex, extend, adduct, abduct, rotate, circumduct
what makes the hip joint sturdy?
dense, strong articular capsule
ligaments to stabilize
muscles to stabilize
true or false: fracture of femoral neck isn’t as common as a dislocation
false
characteristics of a cartilage tear
due to compression and shear stress
fragments may cause joint to lock or bind
cartilage rarely repairs itself
repaired with arthroscopic surgery
sprains
reinforcing ligaments are stretched or torn
what are some common sites of sprains?
ankle, knee, and lumbar region of the back
partial tears (sprains)
repair slowly because of poor vascularization
full tears (sprains)
ends of ligaments can be sewn together, replaced with grafts, or just immobilized for healing
characteristics of dislocations
bones forced out of alignment
caused by serious falls or contact sports
must be reduced to treat
what usually accompany dislocations?
sprains, inflammation of a joint, and difficulty moving joint
subluxation
partial dislocation of a joint
bursitis
inflammation of bursa, usually caused by blow or friction
how is bursitis treated?
rest and ice, anti-inflammatory drugs
tendonitis
inflammation of tendon sheaths, typically caused by overuse
true or false: tendonitis treatment is similar to bursitis treatment
true
characteristics of osteoarthritis
degenerative joint disease
25% women, 15% men over age 60
cumulative wear and tear or genetic
changes in articular cartilage
underlying bone is exposed
characteristics of rheumatoid arthritis
inflammation condition
affects 2.5% of population
synovial membrane inflamed
some cases immune responses mistakenly attacks joint tissues
what are some immune responses that mistakenly attack joint tissues?
allergies, bacteria, viruses, genetic factors