Session 9: Tendons and Ligaments

Question 1

tendons

Answer 1

attach muscles to bone

Question 2

tendons

Answer 2

transmit loads form the muscle to bone

Question 3

tendons

Answer 3

allows muscle belly to remain at an optimal distance from the joint on which it acts

Question 4

ligaments

Answer 4

attach bone to bone

Question 5

ligaments

Answer 5

addresses mechanical stability of joint

Question 6

ligaments

Answer 6

prevents excessive joint displacement so that it does not dislocate

Question 7

Type 1 collagen

Answer 7

makes up ligaments and tendons

cross-links are formed between collagen molecules and are essential to aggregation at the fibril level

Question 8

tendon arrangement

Answer 8

• fibers are in order
• run in one direction (parallel fashion)
• helps to withstand HIGH unidirectional loads during activity

-elastin is not usually present

Question 9

ligament arrangement

Answer 9

• withstands loads in one direction
• but may also withstand smaller loads in OTHER directions
• fibers are not completely parallel (this might allow for some load to be taken in other directions)
• fibers are closely interlaced with one another
• elastin is scarcely present, except ligamentum flavor which has an abundance of elastin

Question 10

Loose areolar CT

Answer 10

what tendons and ligaments are surrounded by

Question 11

loose CT in tendons

Answer 11

forms a sheath to protect the tendon and to enhance gliding

Question 12

Epitendon

Answer 12

a parietal synovial layer beneath the loose CT that decreases friction in tendons that are subjected to high friction like digits

surrounds the entire tendon

Question 13

endotendon

Answer 13

fiber bundles that are wrapped around epitendon for more lubrication

Question 14

Tendo-osseous junction

Answer 14

where collagen fibers of epitendon continue into the bone and become continuous with periosteum

Question 15

enthesis

Answer 15

changing of connective tissue to bone process

Question 16

4 fibrocartilaginous zones

Answer 16

At end of tendon (zone 1), the collagen fibers intermesh with unmineralized fibrocartilage (zone 2). Unmineralized fibrocartilage will eventually become mineralized fibrocartilage (zone 3) and then merge into cortical bone (zone 4)

Question 17

zone 1

Answer 17

at end of tendon

Question 18

zone 2

Answer 18

collagen fibers (at end of tendon) will intermesh with unmineralized fibrocartilage

Question 19

zone 3

Answer 19

unmineralized fibrocartilage will become mineralized fibrocartilage

Question 20

zone 4

Answer 20

mineralized cartilage will merge into cortical bone

Question 21

stress

Answer 21

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

units: N/m^2 or Pa

Question 22

strain

Answer 22

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

units is a % of change

Question 23

toe region

Answer 23

gibers are aligned, but not lengthened yet

Question 24

elastic region

Answer 24

• linear area
• slope to curve occurs
• not overstretched
• can rethin back to normal length/stretch

Question 25

plastic region

Answer 25

• elongation (increase length)
• causing microtear
• stretching (want to go fro shortened/tight to microtearing stage)

Question 26

ultimate failure point

Answer 26

• complete failure/no longer competent

- no longer have enough fibers to do its job

Question 27

viscoelastic properties

Answer 27

• damp, shear force
• how much stretch you get
• includes: time dependent properties and rate dependent properties

Question 28

time dependent properties of viscoelasticity

Answer 28

-material deforms and continues to deform over a finite length of time even if the load remains constant