tendons and ligaments

Question 1

tendons

Answer 1

attach muscle to bone
contractile tissue
transmits loads from the muscle to the bone and gets lever moving
allows muscle belly to remain at an optimal distance from the joint

Question 2

ligaments

Answer 2

connects bone to bone 
addresses mechanical stability of the joint 
passive force 
guides joint motion 
prevents excessive joint displacement

Question 3

what is the most common type of collagen in tendons and ligaments

Answer 3

type 1

Question 4

what is essential to aggregation at the fibril level

Answer 4

cross links between collagen molecules

Question 5

tendon collagen fibers

Answer 5

running primarily parallel and one direction
helps withstand high unidirectional loads
barely any elastin

Question 6

Ligament collagen fibers

Answer 6

fibers are interlaced with each other and aligned in bundles
react to a certain motion primarily but can resist small loads in other directions
elastin is scarcely present

Question 7

example of ligament with elastin

Answer 7

ligamentum flavum

Question 8

what surround tendons and ligaments

Answer 8

loose areolar connective tissue

Question 9

loose CT. in tendons

Answer 9

creates a sheath that protects tendon and enhances gliding

Question 10

epitenon

Answer 10

a parietal synovial layer that is found just below the loose CT in tendons that are subjected to high levels of friction
can also surround endotenon

Question 11

what can continue with the bone at the periosteum at the tendo-osseous junction

Answer 11

the epitenon

Question 12

paratenon surrounds what

Answer 12

the whole ligament or tendon

Question 13

entheses

Answer 13

fibrocartilage and fibrous

Question 14

z-1 fibrocartilaginous zone

Answer 14

parallel collagen fibers

Question 15

Z-2 fibrocartilaginous zone

Answer 15

unmineralized/non calcified fibrocartilage

Question 16

Z-3 fibrocartilaginous zone

Answer 16

mineralized fibrocartilage

Question 17

Z-4 fibrocartilaginous zone

Answer 17

cortical bone

Question 18

stress

Answer 18

internal force per unit of cross-sectional area of the ligament or tendon

Question 19

Strain

Answer 19

proportional increase in length of the ligament or tendon from its original length in response to externally applied loads

Question 20

Toe region of the stress/strain curve

Answer 20

first region; adding force but only enough to align the fibers

Question 21

elastic region of the stress/strain curve

Answer 21

AKA linear region, tissue will rebound after the elongation (rubberband will snap back to its original shape)

Question 22

Plastic region of the stress/strain curve

Answer 22

region where fibers micro-tear and they won’t return to their original shape- stretching to get new length
okay to occur in tendons (flexibility)

Question 23

Ultimate failure point

Answer 23

doesn’t mean that it completely snaps but there aren’t enough fiber structures for it to do its job

Question 24

tendons have a more ___ curve in the elastic region due to greater ____

Answer 24

linear, stiffness

Question 25

around __ % of strain you get less elongation for the same amount of stress

Answer 25

12% strain

Question 26

do ligaments or tendons have a longer toe region

Answer 26

ligaments

Question 27

do ligaments or tendons have a longer plastic region

Answer 27

ligaments

Question 28

adding more fibers to tendon or ligament

Answer 28

will still keep the length even with increasing strength and increasing stiffness

Question 29

Longer ligaments ____ the elongation to failure and ___ the stiffness

Answer 29

increase, decreases, strength is the same

Question 30

viscoelasticity definition

Answer 30

time dependent properties and rate dependent properties

Question 31

time dependent properties

Answer 31

when a viscoelastic material is subjected to either a constant compressive or tensile load, material will deform and continue to deform over a finite length of time even if the load remains constant

Question 32

Stress relaxation

Answer 32

loading is halted safely below the linear region of the curve and the strain is kept cte over an extended period of time

Question 33

if strain is constant

Answer 33

stress will decrease over time because it doesn’t take enough force to continue those creep properties

Question 34

Creep

Answer 34

effective changes over time, won’t cause much micro-tearing but will make changes over time, slow elongation

Question 35

creep test

Answer 35

loading is halted safely below the linear region of the curve and stress is kept constant

Question 36

rate dependent stiffness

Answer 36

when tissues are loaded rapidly they exhibit greater resistance to deformation than if they were loaded slowly
(steeper linear portion)

Question 37

higher strain rates

Answer 37

ligaments and tendons in isolation store more energy, require more force to rupture, undergo greater elongation

Question 38

rapid loading = __ peak force

Answer 38

larger

Question 39

___ will not occur if a force is loaded rapidly

Answer 39

creep

Question 40

injury causes structures to become more ____

Answer 40

fibrocartilaginous

Question 41

longer immobilization = ______ recovery

Answer 41

longer

Question 42

relaxin

Answer 42

released during pregnancy to produce more elasticity

Question 43

in _ to _ weeks there is a __ % decrease in CT ability

Answer 43

6 to 8 weeks, 50 % decrease

there is tissue stiffness and poor nutrition