Joints Flashcards
how do mobility and stability relate
the more mobile a joint the less stable and vice versa
describe a fibrous joint
uses dense fibrous connective tissue to hold the bones firmly together
the joints between the bones of the skull are
fibrous joints
what are the fibrous joints in the skull called
sutures
what is a syndesmosis
type of fibrous joint that unites bones with a sheet of fibrous tissue - partially moveable
give an example of a syndesmosis
interosseous membrane in the forearm that joins the radius and ulna
what is the name of the fibrous joint that holds a tooth into its socket
gomphosis (dento-alveolar syndesmosis)
what are the 2 types of cartilaginous joints
primary and secondary
what is another name for a primary cartilaginous joint
synchondroses
when are primary cartilaginous joints seen
during bone development
what unites the bones in primary cartilaginous joints
hyaline cartilage
give an example of a primary cartilaginous joint
epiphyseal plates - bone epiphysis and shaft are joined by an epiphyseal plate
what happens to the epiphyseal plate when full growth is achieved
epiphyseal plate converts to bone and the epiphyses fuses with the diaphysis (PCJ disappears)
give an example of a primary cartilaginous joint that persists in adulthood
between first rib and sternum
is there much movement in a primary cartilaginous joint
very little - slight bending in early life and permits growth in the length of a bone
what is another name for a secondary cartilaginous joint
symphyses
give 2 examples of secondary cartilaginous joints
- between bodies of vertebra
- between bodies of pubic bones of pelvis
what is the function of the intervertebral disc joints
provide strength and shock absorption as well as considerable flexibility to the vertebral column
compare the joint surface of primary and secondary cartilaginous joints
primary - small layer of cartilage between bones
secondary - thin layer of cartilage and a fibrous cartilaginous disc
describe a synovial joint
joint capsule composed of an outer fibrous layer lined by a serous synovial membrane
what is the function of the synovial membrane
secretes lubricating synovial fluid
what kind of cartilage lines the bones in a synovial joint
articular (hyaline) cartilage
flexion usually moves away from the anatomical position in ______ direction except for what joint
flexion usually moves away from the anatomical position in an anterior direction
- except knee (due to rotation of lower limb during developmet)
shortens or folds over a structure
flexion or extension
flexion
relate extension to flexion
extension moves away from the anatomical position in the opposite direction to flexion
chin to chest is
flexion
what is abduction
movement away from the midline (body wall)
what is adduction
movement towards the midline (body wall)
what is circumduction
combination of flexion, extension, abduction and adduction
is circumduction the same as rotation
no
what is rotation
turning (axial movement) at a joint away (laterally) or towards (medially) the midline
what joints are capable of rotation
ball and socket
pivot
what is supination
turn palm to face ceiling
(can i have some soup)
what is pronation
turn palm to face the floor
how does supination and pronation occur
via movement of the head of the radius in the forearm not in the hand or wrist
what is plantarflexion of ankle
standing on tip toes
what is dorsiflexion of ankle
standing with heel on ground and toes off groun
what is inversion of the foot
twisting foot so that the plantar surface faces medially (big toe off ground)
(plantar surface faces IN)
what is eversion of the foot
twisting foot so that the plantar surface faces laterally (little toe off ground)
what are the 2 movements of the scapula
retraction
protraction
what is retraction of the scapula
when you move scapulae medially towards the midline of back
what is protraction of the scapula
when you move scapulae laterally away from midline
what are the 4 movements of the mandible
elevation - close mouth
depression - open mouth
protraction (protrusion)
retraction (retrusion)
what kind of joint is the thumb
saddle joint (synovial)
what movement is possible at the thumb
opposition / reposition
what is opposition of the thumb
when pulp of thumb crosses palm to touch the pulp of fingertips
what is so special about opposition of the thumb
allows fine controlled grasp movements for tasks such as writing and is unique to humans
what are the 6 types of synovial joint
plane
hinge
saddle
condyloid (ellipsoid)
ball and socket
pivot
what are the least mobile synovial joints
plane
what movements are permitted in plane joints
sliding and gliding between bones in the plane of the articular surfaces
give 2 examples of plane synovial joints
- acromioclavicular joint between acromion of scapula and clavicle
- between carpal bones of wrist
what is the advantage of no large movements between carpal bones of wrist
protects structures that pass through carpal tunnel
plane synovial joints are usually __axial
uniaxial
the opposed surfaces of bones in plane joints are
flat or almost flat
give 2 examples of saddle joints
between clavicle and sternum
caro-metacarpal joint at base of 1st digit - thumb (between trapezium and 1st metacarpal)
what is another name for a saddle joint
double planar
why can saddle joints be called double planar
allow movements occurring around 2 axes at right angles to eachother - biaxial
what movements are permitted at saddle joints
flexion
extension
abduction
adduction
- therefore circumduction
what shape are the articular surfaces in saddle joints
saddle - reciprocally concave and convex
what movements are permitted at hinge joints
flexion and extension
- uniaxial
give an example of a hinge joint
elbow
give an example of when a bone restricts joint movement
extension of elbow is restricted by the bony interlocking of the humerus and ulna
give an example of when a muscle restricts joint movement
flexion of elbow is restricted by muscle mass of biceps brachii and forearm muscles
why does abduction or adduction not occur in hinge joints e.g. elbow
prevented by joint shape and colateral ligaments on medial and lateral sides
give an example of an ellipsoid (condyloid) joint
wrist joint
metocarpophalangeal joints (knuckles)
what movements are allowed at ellipsoid (condyloid) joint
flexion
extension
abduction
adduction
- therefore circumduction
what are the 2 types of synovial joints that allow rotation
pivot
ball and socket
what movement is allowed at a pivot joint
axial rotation - rotation around a central axis (uniaxial)
give 2 examples of a pivot joint
- at head of radius
- atlanto-axial joint
what does the pivot joint at the head of the radius allow
rotation of the head to allow pronation and supination of the forearm
describe the atlanto-axial joint
atlas (C1 vertebra) rotates around the dens of the axis (C2 vertebra) during rotation of head (the ‘no’ movement)
what are the most mobile joints
ball and socket
what movements are permitted at ball and socket joints
flexion
extension
abduction
adduction
medial and lateral rotation
circumduction
ball and socket joints are ___axial
multiaxial
give 2 examples of ball and socket joints
hip
shoulder (gleno-humeral)
describe the hip joint
spherical head of the femur rotates within the socket formed by the acetabulum of the innominate bone (hip bone)
is the hip or shoulder joint more stable
hip - supported by strong ligaments
describe the gleno-humeral joint
shallow socket formed by scapula and relatively large ball formed by the humeral head - makes it more prone to dislocation than hip in adults
what is medial rotation of the humerus at the glenohumeral joint
in anatomical position, rotate arm at the shoulder so that thumb moves from a lateral to medial position
