week 2 teaching: bone tissue

Question 1

function of bone

Answer 1

protect internal orgnas
provide soft tissue attachment sites
provide support and transfer loads
provide rigid kinematic links
facilitate muscle action and body movement
mineral ion store Ca2+, P-, Mg2+
site of blood cell production

Question 2

function of osteoblasts

Answer 2

growing new bones
rehsaping bones to help them change due to age
healing damaged or broken bones

Question 3

what do osteoblasts secrete

Answer 3

bone matrix

Question 4

once osteoblasts are activated,

Answer 4

move into place and deposit bone matrix into spaces on bone that needs to grow or be strengthened/repaired
bone matrix solidifies into healthy, new bone

Question 5

once the osteoblasts have laid down new bone tissue,

Answer 5

differentiate into osteocytes or die

Question 6

function of osteoclasts

Answer 6

dissolve and break down old or damaged bone cells
make space for osteoblasts
release enzymes that break down old bone
trigger chemical reactions on the surface of old bone tissue that dissolve it and create space for newer, stornger tissue

Question 7

osteoclasts target areas of bone…

Answer 7

that have been tagged by osteocytes

Question 8

function of osteocytes

Answer 8

most common type of cell in bone
moniter chnage in pressure and stress that affects bones
send signals to osteoclasts and osteoblasts

Question 9

where are osteoblasts and osteoclasts found

Answer 9

tiny cells found along bone lining and in the bone itself
derived from local mesenchymal cells: progenitor cells

Question 10

osteoblast shape

Answer 10

cube / slightly box shaped

Question 11

osteoclast shape

Answer 11

bigger than osteoblasts
shaped like rounded domes

Question 12

where are osteocytes found and how are they produced

Answer 12

permeate the interior of the bone and produced from fusion of mononuclear blood-bourne precursor cells

Question 13

two types of bone

Answer 13

cancellous bone- spongey/ trabecular 20%
cortical bone - compact 80%

Question 14

where is cancellous bone mainly found

Answer 14

axial skeleton

Question 15

where is cortical bone mainly found

Answer 15

appendicular skeleton

Question 16

cancellous bone location

Answer 16

located in medullary cavity of bone of tubular and short bones

Question 17

structure of cancellous bone

Answer 17

lighter and less dense than cortical bone
consists of trabeculae shaped as plates and rods interspaced between bone marrow
geometrically arranged to withstand local forces transmitted through the bone

Question 18

if the direction of stress changes,

Answer 18

trabeculae of spongy bone can realign

Question 19

why is it significant that cancellous bone has high porosity

Answer 19

high surface area means cancellous bone has higher metabolic activity

Question 20

function of cortical bones

Answer 20

form protective layer around internal cavity
high resistance to bending and torsion-abel to bear the weight of the body

Question 21

structure of cortical bones

Answer 21

outer layer- periosteum
centre of cortical bone: boen marrow cavity

Question 22

periosteum structure and fuction

Answer 22

protects nerves and blood vessels running though cortical bones
interior layer consists of soteoblasts, synthesise bone marrix

Question 23

bone marrow cavity of cortical bones function

Answer 23

stores fat

Question 24

canal system of cortical bones

Answer 24

haversian canals (parallel to long bone) branch from Volkman canal (perpendicular to long bone)

Question 25

why are all bones not cortical

Answer 25

skeletons would be too heavy to move
cavities needed

Question 26

long bone

Answer 26

e.g femur
support muscel movement
cortical shell allows load bearing in a single direction

Question 27

flat bone

Answer 27

e.g cranium/ scapular
thin, wide, may be countered
mostly cortical bone
main role for protection
allow for good muscle attachment

Question 28

short bone

Answer 28

e.g tallus
stability
as wide as it is tall

Question 29

sesamoid bone

Answer 29

e.g platella
forms as part of a tendon or ligament to allow smooth movement

Question 30

irregular bone

Answer 30

irregular shape e.g vertebrae