Tissues of the MSK System 2

Question 1

fxn of ligs

Answer 1

limits joint motion

guide bones as they are moved by muscles or outside forces

stabilizes joint at either extreme of motion

Question 2

where are ligs more lax

Answer 2

mid range of joint motion

Question 3

ligaments are –> vascularized

Answer 3

poorly vascularized

heal poorly

Question 4

what are ligs made of

Answer 4

dense, organized CT

lines of fibers line up with the lines of force

Question 5

what provides tensile strength to ligs

Answer 5

collagen

Question 6

what do ligs contain varying amounts of

Answer 6

elastin

to provide suppleness

determines the amount of movement allowed

Question 7

how are collagen fibers aligned –> ligs

Answer 7

parallel to the forces that the lig must resist

Question 8

how do ligs attach

Answer 8

attachment to bone

Question 9

how do ligaments attach to bone

Answer 9

collagen fibers –> fibrocartilage –> calcified cartilage –> bone

Question 10

elastin content in a ligament is

Answer 10

variable

Question 10

elastin content in cruciate ligs of knee

Answer 10

almost all collagen

very little elastin

resists tensile load w/ minimal elongation

therefore –> excellent knee stabilizer

Question 11

elastin content of ligamentum flavum of spine

Answer 11

almost all elastin

very little collagen

can be stretched a lot before failure

poor ability to resist tensile loading

Question 12

ligament failure is..

Answer 12

fxn of the load

Question 13

what do ligs resist better

Answer 13

slow load better than fast load before failure

Question 14

rapid loading –> ligs

Answer 14

intra-ligamentous lesion

Question 15

slow loading –> ligs

Answer 15

injuries at or near the bone-ligament interface

Question 16

ligament injuries are called

Answer 16

sprains

grades 1-3

Question 17

ligament innervation

Answer 17

highly innervated

Question 18

if there is very little pain after an injury –> ligs

Answer 18

injury may be more severe

if the ligament is torn –> there is less pain v. overstretch

less pain may equal more severe injury –> good diagnostic clue

Question 19

muscle fxn

Answer 19

muscles move body parts

stabilize a joint

Question 20

when muscles act as stabilizers…

Answer 20

reinforcing ligament fxn

Question 21

what are muscles composed of

Answer 21

contractile tissue

non-contractile tissue

Question 22

contractile tissue –> muscle

Answer 22

actin

myosin

sarcomeres

Question 23

non-contractile tissue –> muscle

Answer 23

fascia surrounding muscle

3 layers

Question 24

3 layers of fasica --> non-contractile tissue of muscle

Answer 24

endomysium perimysium epimysium

Question 25

endomysium --> muscle

Answer 25

surrounds individual muscle fiber

Question 26

perimysium --> muscle

Answer 26

surrounds groups of muscle fibers to form fascicles

Question 27

epimysium --> muscle

Answer 27

surrounds muscle fascicles (outermost membrane) to encase entire muscle

Question 28

what are forces generated by the muscle applied to

Answer 28

both contractile and non-contractile tissue

Question 29

tension developed by contraction --> muscles

Answer 29

either or active or passive

Question 30

active tension --> muscles

Answer 30

d/t contractile components actin or myosin

Question 31

passive tension --> muscles

Answer 31

d/t elastic properties of the contractile tissues w/in the muscle

Question 32

how much can muscle fibers shorten

Answer 32

to about 50% of their original length

Question 33

force of contraction is dependent on --> muscles

Answer 33

length of fibers velocity of contraction direction that fiber is moving in at time of contraction

Question 34

how do muscles work

Answer 34

approximating insertion to origin or approximating origin to insertion (usually works distal to proximal)

Question 35

what do tendons do

Answer 35

connect muscles to other structures

Question 36

tendons are compromised of

Answer 36

collagen ground substance cells

Question 37

how is the collagen in tendons oriented

Answer 37

in line w/ the muscle's pull

Question 38

what do tendons do

Answer 38

transmit the force of muscle contraction to bone or other CT that they attach to

Question 39

how much force can a tendon withstand

Answer 39

at least 2x the maximum force that muscles can exert on them

Question 40

musculotendinous jxn

Answer 40

zone where muscle blends into tendinous tissue

Question 41

typically...--> musculotendinous unit

Answer 41

transitional zone is weaker than the body of the muscle/tendon

Question 42

what are some tendons surrounded by

Answer 42

tendon sheath or peritenon

Question 43

example of tendon sheath

Answer 43

achilles tendon and flexor tendons of hand

Question 44

what is a tendon sheath lined w/

Answer 44

synovial membrane

Question 45

what does the tendon sheath do

Answer 45

lubricates the tendon for easier gliding guides the tendon towards the bony attachment

Question 46

failure in the muscle tendon unit may occur

Answer 46

in the muscle itself in the musculotendinous jxn in the tendon itself at tendon-bone insertion

Question 47

where does failure in the muscle tendon unit mostly occur

Answer 47

transitional points