Biomechanics Quiz 2

Question 1

planes of motion: transverse

Answer 1

a horizontal plane; separates superior from inferior

Question 2

planes of motion: frontal / coronal plane

Answer 2

a cut that separates anterior from posterior

Question 3

angular motions

Answer 3

degrees of freedom

axis of rotation

Question 4

accessory motions

Answer 4

translations - sliding or gliding

Question 5

synovial joints: what is a plane joint?

Answer 5

nonaxial, gliding, no rotation

located: between carpals and tarsals

Question 6

flexion vs. flexed

Answer 6

flexion is moving with muscle

flexed is static but flexed muscle

Question 7

hinge joint: location? what type? function?

Answer 7

uniaxial

function: flexion and extension
located: at humero-ulna joint

Question 8

pivot joint: what type? located?

Answer 8

uniaxial

located: where radial head meets ulna

Question 9

saddle joint: what type? where (2 place in body)?

Answer 9

biaxial

located: where carpal meets metacarpal, and also sternoclavicular

Question 10

condyloid joint: what type? function?

Answer 10

biaxial

located: between metacarpals
function: flexion and extension and abduction and adduction (pointing!)

Question 11

ball-and-socket joint:

Answer 11

multiaxial

located: shoulder and hip joint

Question 12

4 tissues important to structure of musculoskeletal system:

Answer 12

1. bone
2. cartilage
3. ligament
4. tendon

Question 13

invivo definition

Answer 13

testing on a live person

Question 14

in vitro definition

Answer 14

testing on a non-living or fresh/frozen

Question 15

connective tissues are composed of living cells, extracellular components consisting of:

Answer 15

• extracellular components* = mature cartilage
  1. collagen
  2. elastin
  3. minerals
  4. water

Question 16

strongest material of musculoskeletal system

Answer 16

bone

Question 17

how many bones in a human body?

Answer 17

206

Question 18

ligaments connect:

Answer 18

bone to bone

Question 19

tendons connect:

Answer 19

bone to muscle

Question 20

functions of bone:

Answer 20

1. mechanical support and protection

2. housing marrow

Question 21

Connective tissues have different mechanical properties depending on …

Answer 21

the direction of the load

Question 22

outer shell of bone is called what type of bone?

Answer 22

lamellar / compact bone also called cortical bone (dense)

Question 23

cortical bone structure

Answer 23

1. Osteon

2. Volkmann’s canals

Question 24

osteon: what do they look like? made up of?

Answer 24

“a straw within a straw within a straw”; concentric rings within rings.

made of: calcium + collagen (extracellular matrix) makes it more sound.

fibers go in different directions.

Question 25

osteon parts: 4 types and what they are

Answer 25

1. lamella(e): each ring in osteon
2. Harversian canals: hole in center of osteon
3. lacuna(e): “space” or little caves where osteocytes reside
4. canaliculi/us: tunnels that connect lacuna to lacuna;

Question 26

major function of canaliculus

Answer 26

osteocyte communication

Question 27

interior scaffolding is called what type of bone?

Answer 27

cancellous / spongy / trabecular

Question 28

osteocytes

Answer 28

mature bone cells that reside between lamellae

Question 29

Haversian canals support what kind of supplies?

Answer 29

veinous
arterial
nervous

Question 30

Volkmann’s canals offer what direction of passage?

Answer 30

horizontal passages

Question 31

Haversian canals offer what direction of passage?

Answer 31

vertical passages

Question 32

osteons are oriented how?

Answer 32

They differ based on bone! The function and loading drives that difference. always vertical (long).

Question 33

draw osteon

highlight a lamella

Answer 33

** in class **

lamella is the actual white bony ring
lacuna are the little black dots separating each lamella ring

Question 34

trabecular bone structure

Answer 34

network of plates and rods
porous
bone marrow

notes:
no canals because it’s porous and made of spongey bone, free flowing blood
no osteons

Question 35

bone by weight: collagen %

Answer 35

35-40% collagen

Question 36

bone by weight: mineral %

Answer 36

45% mineral for strength

Question 37

bone by weight: water %

Answer 37

15-20% water

Question 38

function of osteoblasts

Answer 38

to build

Question 39

function of osteoclasts

Answer 39

break down

Question 40

primary bone cells (blasts, class): located where in general and 3 places in particular?

Answer 40

inner layer of endosteum 1.covers bone and 2. medullary cavity and 3. lines Haversian canals);

note: constant remodeling going on!!!

Question 41

trabecular bone is made up of what three structures?

Answer 41

1. lamella
2. lacuna (rings made up of osteocytes)
3. canaliculi

*everything normal but canals

Question 42

location of primary cells

Answer 42

osteocytes in lacuna

canalicular are little fingers connecting osteocytes

Question 43

what determines strength of bone?

Answer 43

porosity

Question 44

bones are strongest under what type of loads?

Answer 44

compressive

Question 45

Wolff’s law part 1 (general):

Answer 45

bones will adapt to loads!

Question 46

Wolff’s law part 2:

Answer 46

if load increases, bone will remodel to resist more loading

Question 47

cartilage: chondrocytes embedded where?

Answer 47

within extracellular matrix

Question 48

cartilage: extracellular matrix is made up of % each?

Answer 48

1. water 60-80% (hyaline)

2. collagen 10-30% (hyaline)

Question 49

which part of extracellular matrix is framework?

Answer 49

collagen

Question 50

extracellular matrix functions:

Answer 50

1. protect chondrocytes (inside framework)

2. reduce movement friction

Question 51

cartilage: vascular or avascular?

Answer 51

avascular – no blood supply