Bones

Question 1

components of skeletal system

Answer 1

bone
cartilage
joints
ligament
connective tissue

Question 2

function of skeletal system

Answer 2

support against gravity
leverage
protection
storage of calcium
blood cell production

Question 3

types of bone

Answer 3

flat (2 layers of compact bone with dipole in middle)
long (leverage)
short (transfer forces)
irregular (multi purpose)
sutual (bone between skull bones)
sesamoid (small develop in tendons)

Question 4

long bone features

Answer 4

Diaphysis (shaft) main long part of 2 dense bone layers surround bone cavity
epiphyses (ends) made of spongy / trabecular bone covered in articular cartilage

Question 5

osteoclast crusher cell

Answer 5

dissolves old bone to be replaced

Question 6

osteoblast

Answer 6

immature bone cell secreting matrix proteins to become mineralised

Question 7

osteoid

Answer 7

matrix protein

Question 8

osteocytes

Answer 8

mature bone cells maintaining matrix by branching through allowing Ca to travel

Question 9

osteoclasts

Answer 9

multi nucleated cell secreting acid and enzymes to dissolve bone matrix

Question 10

structure of compact bone

Answer 10

osteon (long cylinder)
central canal (tunnel for blood vessels)
lamellae (concentric layers of matrix)
lacunae

Question 11

what causes the osteon to be strong

Answer 11

collagen fibres in different directions

Question 12

features of trabecular bone (sponge)

Answer 12

no ostens
no canal as nutrients can diffuse in
trabeculae (branching network strong in directions)
red and yellow marrow (red=provides nutrients and forms rbc, yellow=stores fat)

Question 13

bone vs forces

Answer 13

osteons = strength in long axis
trabecular - strength in range of directions as trabeculae align according to direction of loading

Question 14

periosteum

Answer 14

membrane outside bone
-outer fibrous layer = collagen fibres

Question 15

endosteum

Answer 15

membrane lining bone
inner cellular layer for metabolism and blood vessels

Question 16

compact vs trabecular bone - structure

Answer 16

C=osteons, canal, concentric lamellae
T=network of cross bridges

Question 17

compact vs trabecular bone - location

Answer 17

C=shaft of long bone
T=inside short / flat bone and epiphyses of long

Question 18

compact vs trabecular bone - blood supply

Answer 18

C=through canal and perforating canal
T=via red bone marrow

Question 19

ossification

Answer 19

formation / conversion to bone

Question 20

intramembrane ossification

Answer 20

inside formation of flat bone

Question 21

endochondrial ossification

Answer 21

bone forming inside cartilage

Question 22

appositional bone growth

Answer 22

adding more bone to outside increasing width

Question 23

remodelling of trabecular bone

Answer 23

as forces apply it become denser and compact into compact bone

Question 24

1st stage of endochondrial ossification

Answer 24

chondrocytes in calcifying matrix enlarge and die

Question 25

2nd stage of endochondrial ossification

Answer 25

osteoblasts cover shaft in a thin layer of bone

Question 26

3rd stage of endochondrial ossification

Answer 26

blood vessels and osteoblasts penetrate to form a primary ossification centre

Question 27

4th stage of endochondrial ossification

Answer 27

primary ossification centre enlarges until meets with collar

Question 28

5th stage of endochondrial ossification

Answer 28

secondary ossification centre formed at epiphyses forming 3 bones

Question 29

growth in bone length

Answer 29

3 sections of bone connected by cartilage allows expansion and stopped by hormones and fusion of cartilage

Question 30

appositional bone growth

Answer 30

bone deposited by osteoblasts outside while inside resorbed by osteoclasts.

Question 31

bone remodelling

Answer 31

continuous growth and breakdown
osteocytes detect forces and adapt to loading

Question 32

stage 1 of fracture repair

Answer 32

bleeding and formation of a clot to hold together bone

Question 33

stage 2 of fracture repair

Answer 33

formation of external callus (cartilage) and internal callus (sponge bone)

Question 34

stage 3 of fracture repair

Answer 34

external callus replaced by bone, internal unites broken ends

Question 35

stage 4 of fracture repair

Answer 35

initial swelling remodelled