Muscoskeletal System 2

Question 1

functional classification of joints

Answer 1

• synarthroses - immovable joints
• amphiarthroses - slightly moveable joints
• diarthroses - freely moveable joints

Question 2

structural classification of joints

Answer 2

• fibrous
• cartilagenous
• synovial

Question 3

fibrous joints

Answer 3

• suture - dense fibrous connective tissue
• syndesmoses - cord/band of connective tissue
• gomphoses - peg-in-socket arrangement surrounded by fibrous tissue/peridontal ligament

Question 4

cartilaginous joints

Answer 4

• synchondroses

- symphyses

Question 5

synovial joints

Answer 5

• gliding
• hinge
• pivot
• condyloid
• saddle
• ball + socket

Question 6

sutures

Answer 6

• occurs between bones of skull
• junction filled with connective tissue
• rigid splices bind bones of skull together tightly

Question 7

syndesmoses

Answer 7

• longer fibrous tissue
• occurs as sheet/membrane
• allows joints to flex

Question 8

cartilaginous

Answer 8

• united by cartilage
• lack joint cavity
• not highly movable

2 types:

• synchondroses
• sympheses

Question 9

synchondroses

Answer 9

• junction of cartilage
• immovable

e. g.
- epiphyseal plate

Question 10

sympheses

Answer 10

• fibrocartilage units bones
• slightly movable
• resilient shock absorber
• provides strength + flexibility

e. g.
- intervertebral discs
- pub symphysis of pelvis

Question 11

synovial joints

Answer 11

• inc most of bodies joints
• all = diarthroses
• all contain fluid-filled joint cavity

Question 12

synovial joints

articular cartilage

Answer 12

• hyaline
• spongy cushions absorb compression
• protects ends of bone = crushed

Question 13

synovial joints

joint cavity

Answer 13

• potential space

- small amount synovial fluid

Question 14

synovial joints

articular capsule

Answer 14

• 2 layers
• outer: fibrous capsule of dense irregular connective tissue
• inner: synovial membrane of loose connective tissue
• lines all internal joint surfaces —> not covered by cartilage

Question 15

synovial joints

synovial fluid

Answer 15

• filtrate of blood
• has special glycoproteins
• nourishes cartilage + acts as slippery lubricant

Question 16

synovial joints

reinforcing ligaments (some joints)

Answer 16

• capsular (most) - thickened parts of capsule
• extra capsular
• intra capsular

Question 17

synovial joints

nerves

Answer 17

• detect pain

- monitor stretch (senses posture + body movements)

Question 18

synovial joints

blood vessels

Answer 18

• rich blood supply

- extensive capillary beds in synovial membrane (produce blood filtrate)

Question 19

reinforcing ligaments

Answer 19

• ligaments reinforce joints

- intrinsic ligaments reinforce capsule

Question 20

what can some joints possess?

Answer 20

articular disc/ meniscus

• those with bone ends of different shapes/fitting poorly

e. g.
- knee
- TMJ (temporomandibular joint)

Question 21

bursae and tendon sheaths

Answer 21

• contain synovial fluid
• bursa: flattened sac lined by synovial membrane
• where ligaments, muscles, tendons/bones overlie and rub against each other

tendon: sheath
- only on tendons subjected to friction

Question 22

joint stability

articular surfaces

Answer 22

• shape plays minor role

- some deep sockets/grooves provide stability

Question 23

joint stability

ligaments

Answer 23

• more, stronger joint
• once stretched, stays stretched
• can stretch only 6 % beyond normal length before tears

Question 24

joint stability

muscle tone

Answer 24

• constant, low level of contractile force
• keeps tension on ligaments
• important on shoulders, knees and arches of foot

Question 25

what are the movements allowed by synovial joints?

Answer 25

• gliding
• angular movements: flexion, extension, abduction, adduction, circumduction
• rotation

Question 26

what are the special movements allowed?

Answer 26

• pronation
• supination
• dorsiflexion
• plantar flexion
• inversion
• eversion
• protraction
• retraction
• elevation
• depression
• opposition

Question 27

flexion

Answer 27

bent knee

Question 28

extension

Answer 28

extend knee

Question 29

hyperextension

Answer 29

bring leg back

Question 30

dorsi flexion

Answer 30

heel

Question 31

plantar flexion

Answer 31

toe

Question 32

abduction

Answer 32

leg out

Question 33

adduction

Answer 33

leg in

Question 34

rotation

Answer 34

twisting

Question 35

circumduction

Answer 35

circular motion

Question 36

supination

Answer 36

palm up

Question 37

pronation

Answer 37

palm down

Question 38

eversion

Answer 38

foot out

Question 39

inversion

Answer 39

foot in

Question 40

protraction

Answer 40

chin forward

Question 41

retraction

Answer 41

chin back

Question 42

elevation

Answer 42

shoulders up

Question 43

depression

Answer 43

shoulders down

Question 44

articular surfaces are essentially …

Answer 44

flat

Question 45

hinge joints

Answer 45

• cylindrical shaped projection of bone fits into trough shaped surface of another bone
• motion = in single plane

e.g. elbow + knee joints

Question 46

pivot joints

Answer 46

rounded end of bone protrudes into ring of bone + ligaments on another bone

only movement allowed = rotation of bone around long axis

Question 47

condyloid joints

Answer 47

oval articular surface of one bone fits into complementary concavity in another

e.g. MCP (metacarpophalangeal)

Question 48

saddle joints

Answer 48

have greater freedom of movement

each surface has concave + convex surface -> fits together

e.g.
carpo-metacarpal joints of thumb

Question 49

ball and socket joints

Answer 49

spherical head of one bone articulates with cupcake socket of another

joints = multiaxial + most freely moving synovial joints

eg

• shoulder
• hip