joints

Question 1

what are joints?

Answer 1

where two bones meet
classified on basis of function and structure

Question 2

what are the three functional classifications of joints?

Answer 2

1. synarthosis-immovable
2. amphiarthrosis- slight movement
3. diarthrosis- freely movable

Question 3

what is the structural classification of joints?

Answer 3

based on type of material connecting bone
presence or absense of a joint cavity

Question 4

what are the three types of joints

Answer 4

fibrous
cartilaginous
synovial

Question 5

what are fibrous joints?

Answer 5

fibrous bones connected by dense regular c.t

Question 6

what are the three types of fibrous joints?

Answer 6

suture- between cranial bones is synartrotic
gomphosis- tooth in socket, periodontal ligament holds tooth in place synarthrotic
syndesmosis- tibia/fibula/radius/ulna amphiarthotic

Question 7

what are cartilagenous joints

Answer 7

connected by cartilage two types

Question 8

what are the two types of cartilagenous joints

Answer 8

synchondrosis- hyaline c.t, epiphyseal plates, 1st rib to sternum, synarthrotic
symphysis- fibrocartilage, pubic symphysis, intervertebral discs amphiarthrotic

Question 9

what are synovial joints?

Answer 9

fluid-filled joint cavity
consists of 3 kinds

Question 10

what are the three types of synovial joints?

Answer 10

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

Question 11

what is the structure of synovial joints?

Answer 11

diarthrotic- freely moveable
fluid filled cavity joiny cavity- fluid secreted by fibroblasts in synovial membrane

Question 12

what is the synovial membrane?

Answer 12

secrete synovial fluid

Question 13

what is synovial cavity?

Answer 13

contains synovial fluid and lubricates

Question 14

what is hylaline c.t?

Answer 14

protects ends of bones

Question 15

what is the fibrous capsule?

Answer 15

thickening of periosteum to enclose joint

Question 16

what is the periosteum?

Answer 16

membrane around the bone

Question 17

what are the five compentents to synovial joints?

Answer 17

synovial membrane
synovial cavity
hyaline c.t
fibrous capsule
periosteum

Question 18

what are the functions of synovial fluid?

Answer 18

absorbs shock(consistency of egg white= proteoglycans +tissue fluid)
reduces friction- between articulating surfaces
nourishes chondrocytes- c.t is avascular has no blood suply

Question 19

affects of exercise on synovial fluid?

Answer 19

increases the temp of the fluid= becomes less viscous and flows more easily
stimulates production of synovial fluid
helps circulate synovial fluid

Question 20

what are the structures associated of synovial joints?

Answer 20

1. bursa
   2.tendon sheath
2. ligaments
3. tendons c.t
4. meniscus

Question 21

what is the bursa?

Answer 21

fluid filled sacs (dense c.t lined in synovial membrane occur where muscles/tendons/skin rub over bone)

Question 22

what is a tendon sheath?

Answer 22

elongated bursa wrapped around a tendon= bun around weiner arrangement

Question 23

what are ligaments?

Answer 23

hold bone to bone dense regular c.t
stabilizes joints and determines flexibilty of joints

Question 24

what are tendons?

Answer 24

attach muscles to bones dense regular c.t

Question 25

what is a meniscus?

Answer 25

pad of fibrocartilage between joints (knee joints) resists compression channels flow of synovial fluid

Question 26

how does muscle attachement occur?

Answer 26

tendons connect muscle to bone dense regular muscles are attached to bone= contractions move bones

Question 27

where does movement of muscle attachment occur?

Answer 27

occurs at joints (articulations) system of levers most muscles have two points of attachment

Question 28

what is the orgin?

Answer 28

point of attachment on stationary bone

Question 29

what is insertion?

Answer 29

point of attachment on bone that moves

Question 30

what are muscle groups?

Answer 30

actions (movements) at joints are brought about by 3 general groups of muscles

Question 31

what are the three muscle groups?

Answer 31

1. prime mover(agonist)- muscle cheifly responcible for movement 2. synergist-assists the prime motor 3. antagonist- opposes the action of the agonist

Question 32

what are muscle actions?

Answer 32

types of movements produced at joints by muscle contraction

Question 33

what is abduction?

Answer 33

movement away from the midline

Question 34

what is adduction?

Answer 34

movement towards midline

Question 35

what is flexion?

Answer 35

movement that reduces angle between 2 bones

Question 36

what is extension?

Answer 36

movement that increases angle between 2 bones

Question 37

what is pronation?

Answer 37

movement of forearm so palms face posterioly

Question 38

what is supination?

Answer 38

movement of forearm so palm faces anteriorly

Question 39

what is dorsifelxion?

Answer 39

flexing ankles so toes lift

Question 40

what is plantar flexion?

Answer 40

pointing toes

Question 41

what is elevation?

Answer 41

movement in superior direction

Question 42

what is depression?

Answer 42

movement in inferior direction?

Question 43

what is protraction?

Answer 43

movement in anterioly in horizontal plane

Question 44

what is retraction?

Answer 44

movement posteriorly in horizontal plane