joints Flashcards
what are joints?
where two bones meet
classified on basis of function and structure
what are the three functional classifications of joints?
- synarthosis-immovable
- amphiarthrosis- slight movement
- diarthrosis- freely movable
what is the structural classification of joints?
based on type of material connecting bone
presence or absense of a joint cavity
what are the three types of joints
fibrous
cartilaginous
synovial
what are fibrous joints?
fibrous bones connected by dense regular c.t
what are the three types of fibrous joints?
suture- between cranial bones is synartrotic
gomphosis- tooth in socket, periodontal ligament holds tooth in place synarthrotic
syndesmosis- tibia/fibula/radius/ulna amphiarthotic
what are cartilagenous joints
connected by cartilage two types
what are the two types of cartilagenous joints
synchondrosis- hyaline c.t, epiphyseal plates, 1st rib to sternum, synarthrotic
symphysis- fibrocartilage, pubic symphysis, intervertebral discs amphiarthrotic
what are synovial joints?
fluid-filled joint cavity
consists of 3 kinds
what are the three types of synovial joints?
1.monaxial- movement in 1 plane
hinge joints-knee, elbow
pivot joints-atlas to axis
2. biaxial- movement in 2 planes
saddle joints-base of thumb
condylar- base of fingers
3.multiaxial- movement in over two planes
ball and socket joints- hip, shoulder
plane/gliding joints- intercarpel
all synovial are classified as diarthortic
what is the structure of synovial joints?
diarthrotic- freely moveable
fluid filled cavity joiny cavity- fluid secreted by fibroblasts in synovial membrane
what is the synovial membrane?
secrete synovial fluid
what is synovial cavity?
contains synovial fluid and lubricates
what is hylaline c.t?
protects ends of bones
what is the fibrous capsule?
thickening of periosteum to enclose joint
what is the periosteum?
membrane around the bone
what are the five compentents to synovial joints?
synovial membrane
synovial cavity
hyaline c.t
fibrous capsule
periosteum
what are the functions of synovial fluid?
absorbs shock(consistency of egg white= proteoglycans +tissue fluid)
reduces friction- between articulating surfaces
nourishes chondrocytes- c.t is avascular has no blood suply
affects of exercise on synovial fluid?
increases the temp of the fluid= becomes less viscous and flows more easily
stimulates production of synovial fluid
helps circulate synovial fluid
what are the structures associated of synovial joints?
- bursa
2.tendon sheath - ligaments
- tendons c.t
- meniscus
what is the bursa?
fluid filled sacs (dense c.t lined in synovial membrane occur where muscles/tendons/skin rub over bone)
what is a tendon sheath?
elongated bursa wrapped around a tendon= bun around weiner arrangement
what are ligaments?
hold bone to bone dense regular c.t
stabilizes joints and determines flexibilty of joints
what are tendons?
attach muscles to bones dense regular c.t
what is a meniscus?
pad of fibrocartilage between joints (knee joints)
resists compression
channels flow of synovial fluid
how does muscle attachement occur?
tendons connect muscle to bone dense regular
muscles are attached to bone= contractions move bones
where does movement of muscle attachment occur?
occurs at joints (articulations) system of levers
most muscles have two points of attachment
what is the orgin?
point of attachment on stationary bone
what is insertion?
point of attachment on bone that moves
what are muscle groups?
actions (movements) at joints are brought about by 3 general groups of muscles
what are the three muscle groups?
- prime mover(agonist)- muscle cheifly responcible for movement
- synergist-assists the prime motor
- antagonist- opposes the action of the agonist
what are muscle actions?
types of movements produced at joints by muscle contraction
what is abduction?
movement away from the midline
what is adduction?
movement towards midline
what is flexion?
movement that reduces angle between 2 bones
what is extension?
movement that increases angle between 2 bones
what is pronation?
movement of forearm so palms face posterioly
what is supination?
movement of forearm so palm faces anteriorly
what is dorsifelxion?
flexing ankles so toes lift
what is plantar flexion?
pointing toes
what is elevation?
movement in superior direction
what is depression?
movement in inferior direction?
what is protraction?
movement in anterioly in horizontal plane
what is retraction?
movement posteriorly in horizontal plane
