lecture 9 ; joints Flashcards
- rigid elements of the skeleton meet at joints or articulations
- structure; enables resistance to crushing, tearing and other forces
joints
joints classified as function
- synarthroses
- amphiarthroses
- diarthroses
immovable ; common in axial skeleton
synarthroses
slightly movable; common in axial skeleton
amphiarthroses
freely moveable ; common in appendicular skeleton
diarthroses
joints classify as structural
- fibrous
- cartilaginous
- synovial
- bones connected by fibrous connective tissue
- no joint cavity
- most immovable or slightly movable
- types; sutures, syndesmoses, gomphoses
fibrous joints
- bones are tightly bound by a minimal amount of fibrous tissue
- occur between bones of the skull
- allow bone growth so skull can expand during childhood
sutures
- closed sutures
- bones connected exclusively by ligaments
synostoses
immovable synarthrosis
tibiofibular joint
- tooth in a socket
- connecting ligament ; periodontal ligament
gomphoses
-bones are united by cartilage
-lack a joint cavity
two types ; synchondroses and symphyses
cartilaginous joints
- hyaline cartilage unites bones
- -epiphyseal plates
- joints between first rib and manubrium
synchondroses
- unites bones; resists tension and compression
- slightly movable joints that provide strength with flexibility
- -intervertebral discs
- pubic symphysis
fibrocartilage
present as articular cartilage
hyaline cartilage
- ends of opposing bones are covered with hyaline cartilage
- absorbs compression
articular cartilage
- unique to synovial joints
- cavity is a potential space that holds a small amount of synovial fluid
joint cavity
joint cavity is enclosed in a two-layered capsule
articular capsule
dense irregular connective tissue, which strengthens joint
fibrous layer
- loose connective tissue
- lines joint capsule and covers internal joint surfaces
- functions to make synovial fluid
synovial membrane
a viscous fluid similar to raw egg white.
- filtrate of blood
- arises from capillaries in synovial membrane
- contains glycoprotein molecules secreted by fibroblasts
synovial fluid
pressure on joints squeeze synovial fluid into and out of articular cartilage
weeping lubrication
- often are thickened parts of fibrous layer
- sometimes are extra capsule ligaments ; located outside the capsule
- sometimes in intracapsular ligaments ; located internal to the capsule
reinforcing ligaments
- lubricating devices
- friction could overheat and destroy joint tissue
- subjected to compressive forces
- fluid squeezed out as opposing cartilages touch
- cartilages ride on slippery film
synovial joints
- not synovial joints
- closed bags of lubricant
- reduce friction between body elements
bursae and tendon sheaths
a flattened fibrous sac lined by a synovial membrane
bursa
an elongated bursa that wraps around a tendon
tendon sheath
3 movements allowed by synovial joints
- gliding
- angular movement
- rotation
-one bone across the surface of another
gliding
movements change the angles between bones
angular movement
- movement around a bones long axis
- only movement allowed between atlas and axis vertebrae
- occurs at the hip and shoulder joints
rotation
- flat surfaces of two bone slip across each other
- occurs between ;
- carpals
- articular processes of vertebrae
- tarsals
gliding joints
- increase or decrease angle between bones
- movements involve;
- flexion and extension
- abduction adduction
- circumduction
angular movements
special movements
- elevation
- depression
- protraction
- retraction
- supination
- pronation
- opposition
- inversion
- eversion
- dorisflexion
- plantar flexion
lifting a body part superiorly
elevation
moving the elevated part inferiorly
depression
nonangular movement anteriorly
protraction
nonangular movement posteriorly
retraction
forearm rotates laterally, palm faces anteriorly
supination
forearm rotates medially, palm faces posteriorly
-brings radius across the ulna
pronation
thumb moves across the palm to touch the tips of other fingers
opposition
-turns sole of foot medially
inversion
turns sole of foot laterally
eversion
-lifting the foot so its superior surface approaches the shin
dorsiflexion
depressing the foot, elevating the heel
plantar flexion
5 synovial joints classified by shape
- plane joint
- hinge joints
- pivot joints
- condylar joints
- saddle joints
- ball and socket joint
- articular surfaces are flat planes
- short gliding movements are allowed
- movements are nonaxial
plane joint
- cylindrical end of one bone fits into a trough on another bone
- angular movement is allowed in one plane
- elbow, ankle, and joints between phalanges
- movement is uniaxial
hinge joints
-classified as uniaxial ; rotating bone turns only around its long axis
pivot joints
- allow moving bone to travel
- side by side - abduction/adduction
- back and forth -flexion/extension
- classified as biaxial ; movement occurs around two axes
condylar joints
- each articular surface has concave and convex surfaces
- classified as biaxial joints
- allows opposition of the thumb
saddle joints
- spherical head of one bone fits into round socket of another
- classified as multiracial ; allows movements in all axes
- shoulders and hips are examples
ball and socket joints
- shapes of articulating surfaces determine movements possible
- seldom play major role in joint stability
articular surfaces
- prevent excessive motions
- on medial or inferior side of a joint
ligaments
- helps stabilize joints by keeping tensions on tendons
- important in reinforcing ; shoulder and knee joints
- supporting joints in arches of the foot
muscle tone
- saddle joint
- four ligaments surround joint
- performs multiple complex movements
- anterior and posterior sternoclavicular ligaments
- interclavicular ligament
- costoclavicular ligament
sternclavicular joint
- modified hinge joint
- head of the mandible articulates with the temporal bone
- lateral excursion is a side to side movement
- two surfaces of the articular disc allow; hingleike movement and gliding of superior surface anteriorly
temporomandibular joint
common injury to meniscus of knee joint
torn cartilage
ligaments of a reinforcing joint are stretched or torn
sprains
occurs when the bones of a joint are forced out of alignment
dislocation
inflammation of a bursa due to injury or friction
bursitis
inflammation of a tendon sheath
tendonitis
describes over 100 kinds of joint damaging diseases
arthritis
most common type of wear and tear arthritis
osteoarthritis
a chronic inflammatory disorder
rheumatoid arthritis
uric acid buildup causes pain in joints
gouty arthritis
inflammatory disease often resulting in joint pain
lyme disease
