articulations Flashcards
what is another name for a joint
articulation
definition of an articulation (3)
place of contact between
- bones
- bone and cartilage
- bones and teeth
how can joints be characterised (2)
- structurally
- functionally
how is a joint characterised structurally (2)
- whether a space occurs between articulating bones
- type of connective tissue binding the articulating surfaces
what are the 3 structural joint classifications
- fibrous
- cartilaginous
- synovial
describe a fibrous joint (2)
- no joint cavity
- ends of bones and bone parts are held together by dense regular (fibrous) tissue
describe a cartilaginous joint (2)
- no joint cavity
- bones are joined by a pad of cartilage wedged between ends of bones
describe a synovial joint (4)
- joint cavity, which contains synovial fluid, separates articulating surfaces
- lined by a synovial membrane
- articulating surfaces are enclosed within a connective tissue capsule (articular capsule)
- bones are attached to each other by various ligaments
what are the 3 structural categories of fibrous joints
- gomphosis
- suture
- syndesmosis
what are the 2 functional classifications of fibrous joints
- synarthrosis
- amphiarthrosis
what are the 2 structural categories of cartilaginous joints
- synchondrosis
- symphysis
what are the 2 functional classifications of cartilaginous joints
- synarthrosis
- amphiarthrosis
what are the 6 structural categories of synovial joints
- plane
- hinge
- pivot
- condylar
- saddle
- ball-and-socket
what is the functional classification of synovial joints
diarthrosis
what are the 3 functional classifications
- synarthrosis
- amphiarthrosis
- diarthrosis
describe a synarthrosis joint (3)
- immobile
- fibrous: gomphosis and sutures are synarthroses
- cartilaginous: synchondroses are synarthroses
describe an ampiarthrosis joint (3)
- slightly mobile
- fibrous: syndesmoses are amphiarthroses
- cartilaginous: symphyses are amphiarthroses
describe a diarthroses joint (2)
- freely mobile
- all synovial joints are diarthroses
if a joint is highly mobile, is it also highly stable
no
describe gomphosis (2)
- periodontal membranes hold a tooth to bony jaw
- synarthrosis
describe sutures (2)
- connects skull bones
- synarthrosis
describe syndesmosis (2)
- interosseous membranes (dense regular CT) between bones
- amphiarthrosis
what are the alveolar processes
sockets for each individual teeth
describe the appearance of sutures (3)
- distinct
- interlocking
- irregular
edges
what is the role of the sutures (2)
- increase strength
- decrease fractures
how are synostoses formed
in an older adult, dense regular connective in the suture ossify, fusing skull bones together
what are articulating bones of syndesmoses joined by
long strands of dense regular connective tissue
where are syndesmosis found (2)
- radius and ulna
- tibia and fibula
what are the shafts of the 2 articulating bones bound by in syndesmoses
broad, ligamentous sheet called the interosseous membrane
what does the interosseous membranes provide
pivot for which articulating bones can move relative to each other
describe synchondroses (2)
- contains hyaline cartilage
- synarthroses
what do the epiphyseal plates of children form
synchondroses that bind the epiphyses and diaphysis of long bones
what happens when hyaline cartilage stops growing in epiphyseal plates
bone replaces the cartilage and synchondroses no longer exists
describe symphyses (2)
- contains fibrocartilage
- amphithroses
when does the spheno-occipital synchondrosis fuse
between 18 and 25 years of age
what are 2 examples of synchondroses in the ribcage
- costochondral joint; the joint between each bony rib and its respective costal cartilage
- the attachment of the first rib to the sternum by costal cartilage
what does a symphysis has between the articulating bones
a pad of fibrocartilage
what does the fibrocartilage in a symphysis resist (2)
- compression
- tension stresses
acting as a resilient shock absorber
examples of locations of symphyses (2)
- pubic symphysis
- intervertebral joints
what are the 7 basic features of a synovial joint
- an articular capsule
- a joint cavity
- synovial fluid
- articular cartilage
- ligaments
- nerves
- blood vessels
how many layers is the articular capsule
2
what are the names of the 2 layers of the articular capsule
- fibrous layer (outer)
- synovial membrane (inner)
what is the outer fibrous layer of synovial joint made of
dense connective tissue
what does the outer fibrous layer of synovial joint do
strengthens the joint to prevent the bones from being pulled apart
what does the articular cartilage in synovial joints lack
a perichondrium
why is exercise vital to maintaining a healthy articular cartilage
- mature cartilage, chondrocytes, is avascular so nutrients and removal of waste products is slower
- repetitious compression and expansion in exercise enhances its nutrition obtaining and waste removal
what is a joint cavity
a space that permits separation of the articulating bones
what sort of substance is synovial fluid
viscous and oily
what two things produces synovial fluid
- synovial membrane cells
- filtrate formed from blood plasma
what are the 3 functions of synovial fluid
- lubricates the articular cartilage
- nourishes the articular cartilage’s chondrocytes
- acts as a shock absorber
how does synovial fluid nourish the chondrocytes of articular cartilage (2)
- the small volume of synovial fluid must be circulated continually
- whenever there is movement at the joint, the combined compression and re-expansion of articular cartilage circulates the fluid in and out of the cartilage matrix
how does synovial fluid act as a shock absorber
it distributes stress and force evenly across articular surfaces when pressure in the joint suddenly increases
what do ligaments do to synovial joints (3)
- stabilize
- strengthen
- reinforce
what are the 2 types of ligaments in synovial joints
- intrinsic ligaments
- extrinsic ligaments
what do intrinsic ligaments represent
thickenings of the articular capsule
where are extrinsic ligaments located
outside of and physically separate from the joint capsule
what do the sensory nerves do (2)
- detect painful stimuli
- report on the amount of movement and stretch
are tendons a part of the synovial joint itself
no
how do tendons help stabilize a joint (3)
- they pass across or around a joint to provide mechanical support
- limit the range or amount of movement permitted by joint
describe a bursa
a fibrous, saclike structure containing synovial fluid, lined internally by a synovial membrane
how can bursae be connected (2)
- connected to joint cavity
- completely separate from joint cavity
what is a tendon sheath
an elongated bursa
where are fat pads distributed in the synovial joint
along the periphery of the joint
what are the 3 descriptions of synovial joints in respect to the movement of bone
- uniaxial
- biaxial
- multiaxial/triaxial
describe a uniaxial joint
the bone moves in just 1 place or axis
describe a biaxial joint
the bone moves in 2 planes or axes
describe a multiaxial/triaxial joint
the bone moves in multiple planes or axes
list the 6 synovial joints from least mobile to most freely mobile
- plane
- hinge
- pivot
- condylar
- saddle
- ball-and-socket
describe a plane joint’s movement
uniaxial
describe a hinge joint’s movement
uniaxial
describe a pivot joint’s movement
uniaxial
describe a condylar joint’s movement
biaxial
describe a saddle joint’s movement
biaxial
describe a ball-and-socket joint’s movement
multi/triaxial
what are the 4 motions of synovial joints
- gliding motion
- angular motion
- rotational motion
- special movement
what is gliding motion
2 opposing articular surfaces slide past each other in any direction, the movement is slight
what is angular motion
the angle between articulating bones increases or decreases
what are the 7 types of angular motion
- flexion
- extension
- hyperextension
- lateral flexion
- abduction
- adduction
- circumduction
describe a flexion
the angle between articulating bones decreases in an anterior-posterior (AP) plane
describe an extension
the angle between articulating bones increases in an anterior-posterior (AP) plane
describe a hyperextension
extension movement continues past 180 degrees
describe a lateral flexion
the vertebral column moves (bends) in a lateral direction along a coronal plane
describe an abduction
lateral movement of a body part away from the midline
describe an adduction
lateral movement of a body part toward the midline
describe circumduction
a continuous movement that combines flexion, abduction, extension and adduction in succession; the distal end of the limb or digit moves in a circle
what are the 2 types of rotational motion
- pronation
- supination
what is rotational movement
a bone pivots around its own longitudinal axis
describe pronation
rotation of the forearm where the palm is turned posteriorly or inferiorly
describe supinatino
rotation of the forearm where the palm is turned anteriorly or superiorly
what are special movements of the synovial joints
types of movement that do not fir into the previous categories
what are the 9 types of special movements
- depression
- elevation
- dorsiflexion
- plantar flexion
- eversion
- inversion
- protraction
- retraction
- opposition
describe depression of a synovial joint
movement of a body part inferiorly
describe elevation of a synovial joint
movement of a body part superiorly
describe dorsiflexion of a synovial joint
ankle joint movement where the dorsum (superior surface) of the foot is brought toward the anterior surface of the leg
describe plantar flexion
ankle joint movement where the sole of the foot is brought toward the posterior surface of the leg
describe eversion
twisting motion of the foot that turns the sole laterally or outward
describe inversion
twisting motion of the foot that turns the sole medially or inward
describe protraction
anterior movement of a body part from anatomic position
describe retraction
posterior movement of a body part from anatomic position
describe opposition of the synovial joint
special movement of the thumb across the palm toward the fingers to permit grasping and holding of an object
what is the opposing movement of flexion
extension
what is the opposing movement of extension
flexion
what is the opposing movement of hyperextension
flexion
what is the opposing movement of lateral flexion
none
what is the opposing movement of abduction
adduction
what is the opposing movement of adduction
abduction
what is the opposing movement of circumduction
none
what is the opposing movement of pronation
supination
what is the opposing movement of supination
pronation
what is the opposing movement of depression
elevation
what is the opposing movement of elevation
depression
what is the opposing movement of dorsiflexion
plantar flexion
what is the opposing movement of plantar flexion
dorsiflexion
what is the opposing movement of eversion
inversion
what is the opposing movement of inversion
eversion
what is the opposing movement of protraction
retraction
what is the opposing movement of retraction
protraction
what is the opposing movement of opposition
reposition
where does gliding occur
along plane joints such as between carpals or tarsals
what are 4 examples of flexion occuring
- bend fingers towards palm, making a fist
- bend forearm towards arm at elbow
- flexion at shoulder when arm is raised anteriorly
- flexion at neck when head is bent anteriorly
what are 2 examples of extension
- straightening arm and forearm
- straightening fingers
