Cartilage and bone

Question 1

name the things that can affect regulation of cartilage growth

Answer 1

stimulate protein synthesis
retard protein synthesis
tumours

Question 2

describe what stimulates protein synthesis for cartilage growth

Answer 2

growth hormone - regulates cartilage growth (leads to bone growth)
thyroid hormone
testosterone

Question 3

describe what retards protein synthesis for cartilage growth

Answer 3

corticosteroids
estradiol
retinoids (vitamin A, reduced growth)

Question 4

describe what effect tumours have for cartilage growth

Answer 4

chondroma
chondrosarcoma
if chondrogenic layer is messed up - leads to tumours (POLARITYYY)

Question 5

what is one of the hardest tissues of body

Answer 5

bone
can withstand lots of stress

Question 6

what is ecm of bone made of

Answer 6

calcified material
type 1 collagen

Question 7

describe the type 1 collagen of bone - what it does

Answer 7

helical structure
length of long bones
allows bones to bend without breaking

Question 8

name the 4 cell types in bone

Answer 8

osteoprogenitor cells
osteoblasts
osteocytes
osteoclasts

Question 9

describe osteoprogenitor cells

Answer 9

committed stem cells - already on lineage to become osteoblasts, cytes or clasts

Question 10

describe osteoblasts

Answer 10

synthesize organic components of matrix

Question 11

describe osteocytes

Answer 11

found in lacunae - trapped in ecm of bone

Question 12

describe osteoclasts

Answer 12

multinucleated cells
involved in bone resorption (remodelling) - reabsorb calcium in bone
own line of differentiation

Question 13

what is ecm of bone produced by

Answer 13

osteoblasts

Question 14

describe components of ecm of bone

Answer 14

fibers - collagen type 1
ground substance - proteoglycans, glycoproteins
minerals - crystals of hydroxyapatite (Ca10(PO4)6(OH)2)

Question 15

name the 2 glycoproteins found in ecm of bone

Answer 15

sialoprotein
osteocalcin

Question 16

describe histological techniques for bone

Answer 16

special technique
called decalcification
5% nitric acid or ETDA treatment
remove calcium from bone so its easier to cut - left with a rubbery material

Question 17

name the 3 classifications of bone

Answer 17

gross appearance
microscopy appearance
development appearance

Question 18

describe gross appearance of bone

Answer 18

compact
cancellous (spongy)

Question 19

describe microscopy appearance of bone

Answer 19

woven (immature)
lamellar (mature)

Question 20

describe development appearance of bone

Answer 20

intramembranous- come from membrane of mesenchymal cells
endochondral - ossification of cartilage

Question 21

what is epiphysis and diaphysis

Answer 21

epiphysis = top
diaphysis = bottom

Question 22

why is calcium important

Answer 22

cofactor for metabolic processes

Question 23

is compact bone mature

Answer 23

um yes

Question 24

what do long bones come from

Answer 24

cartilage

Question 25

describe periosteum

Answer 25

dense irregular ct forms sheath around bone fibrocytes - stuck in matrix collagen type 1 fibers some osteoprogenitor cells

Question 26

describe outer circumferential system

Answer 26

lost of extracellular space 3-4 layers of osteocytes parallel to periosteum - around bone

Question 27

describe inner circumferential system

Answer 27

osteocytes 2-3 layers on top of endosteum

Question 28

describe endosteum

Answer 28

1 layer of osteoprogenitor cells flat closest to bone marrow

Question 29

what is system aka

Answer 29

lamellae

Question 30

what is an osteon

Answer 30

haversian system

Question 31

describe interstitial system

Answer 31

between haversian systems old haversian systems being turned over and uptaken circular radial pattern

Question 32

describe volkmann's canal

Answer 32

horizontal drains into bone marrow space

Question 33

describe haversian canal

Answer 33

run lengthwise through bones nerves go through here

Question 34

describe haversian system

Answer 34

osteocytes tunnels run through them

Question 35

describe trabecular bone

Answer 35

looks cuboidal osteoblasts makes ecm and fivers and divide or differentiate to osteocytes that are trapped in matrix osteoclasts on side - round and big, multiple nuclei, breaks down ca

Question 36

describe precisely where collagen fibers are in bone

Answer 36

wrap around haversian systems and interstitial (can be degraded - contents are recycled) contribute to tensile strength - go up and down

Question 37

how are osteons separated

Answer 37

cementin line - made up of protein cementin goes around osteon and delineates one haversian system from another

Question 38

describe how nutrients pass through osteocytes

Answer 38

pass from cell/layers then catabolic material must go back to blood supply so osteocytes can form canaliculi

Question 39

what are canaliculi

Answer 39

channels with cellular processes how nutrients are delivered to osteocytes at cementin line

Question 40

how do osteocytes form canaliculi

Answer 40

osteocytes send out cellular processes and tentacles - makes up the canaliculi bind and communicates with cell in next layer

Question 41

what do osteoclasts first do

Answer 41

sit down on bone matrix and fuses - makes ruffle border makes circumferential clearing zone which protects cell

Question 42

what do lysosomes do (osteoclasts)

Answer 42

carry proteins made from nucleus golgi - packaged and lysosomes send their packages (contents) in to zone

Question 43

what else does it (osteoclasts) send out that is important

Answer 43

sends out acid phosphatsases - protein made in nucleus RER - packaged by lysosomes and finds its way to zone packs zone with acid phophatases

Question 44

what happens after area is packed with acid phosphatases

Answer 44

cell uses carbonic anhydrase to make area acidic, since acidic phosphotases need an acidic environment to work pumps H+ into zone, while it ships off bicarb to be removed makes acidic environment

Question 45

what happens after osteoclasts chew up bone

Answer 45

ca gets transported through osteoclasts and up blood stream blood is being monitored for calcium concentration