Lab 4: Bone

Question 1

describe classifications of bone

Answer 1

compact vs cancellous
lamellar vs woven

Question 2

what is difference between compact and cancellous bone

Answer 2

compact is compact and more uniform
cancellous is spongy bone - looks porous

Question 3

what is difference between lamellar and woven bone

Answer 3

lamellar is organized
woven is disorganized

Question 4

describe lamellar bone

Answer 4

arranged in sheets
80% within compact bone
20% within spongy bone

Question 5

describe woven bone

Answer 5

arranged randomly
growing and developing bones

Question 6

what type of collagen is in bone

Answer 6

collagen type 1

Question 7

name cells of bone

Answer 7

osteoblasts
osteocytes
osteoclasts

Question 8

describe osteoblasts

Answer 8

cuboidal
eccentrically located nucleus

Question 9

describe osteocytes

Answer 9

most abundant
appear flattened

Question 10

describe osteoclasts

Answer 10

large multi nucleated cells
function in reabsorption of bone

Question 11

name the important parts of bone

Answer 11

collagen type 1
cells
endosteum/periosteum
inner/outer circumferential systems (lamaellae)
haversian systems/canals

Question 12

name parts of long bone

Answer 12

diaphysis
epiphyses

Question 13

describe diaphysis

Answer 13

diaphysis = compact bone surrounding marrow cavity

Question 14

describe epiphyses

Answer 14

epiphyses = spongy bone within compact bone and cartilage on the joint surfaces

Question 15

what is epiphyseal plate

Answer 15

disc of cartilage that grows during childhoos

Question 16

what is epiphyseal line

Answer 16

remnant of epiphyseal plate

Question 17

describe periosteum of epiphyseal plate (2 layers)

Answer 17

outer fibrous layer of dense irregular ct
inner osteogenic layer containing primitive stem cells

Question 18

what is a haversian system aka

Answer 18

osteon

Question 19

what is compact lamellar bone

Answer 19

mature bone

Question 20

describe center of compact lamellar bone

Answer 20

marrow cavity
made by endosteum
composed of osteoblasts

Question 21

what does endosteum produce (compact lamellar bone)

Answer 21

inner circumferential lamellae
concentric to bone

Question 22

describe exterior of compact lamellar bone

Answer 22

periosteum

Question 23

describe periosteum of compact lamellar bone (layers)

Answer 23

fibrous layer
osteogenic layer

Question 24

what does osteogenic layer produce (compact lamellar bone)

Answer 24

outer circumferential lamellae
concentric to bone

Question 25

what are in between inner and outer circumferential lamellae

Answer 25

round haversian systems

Question 26

what is in center of each haversian system (compact lamellar bone)

Answer 26

haversian canal
run lenght of long bone
joined perpendicularly by Volkmann canals

Question 27

what delineates haversian systems (compact lamellar bone)

Answer 27

cementing lines

Question 28

what are inbetween haversian systems (compact lamellar bone)

Answer 28

Interstitial systems

Question 29

describe growth of long bones

Answer 29

longitudinal
first starts off with cartilage and mineralized cartilage matrix –> grows more and eventually bone growth

Question 30

name the 5 zones of the epiphyseal plate

Answer 30

zone of resting cartilage
zone of proliferation
zone of hypertrophy
zone of cell death
zone of mixed spicules

Question 31

describe zone of resting cartilage (layers of epiphyseal plate)

Answer 31

inactive chondrocytes
ecm = hyaline cartilage (collagen type 2)

Question 32

describe zone of proliferation (layers of epiphyseal plate)

Answer 32

dividing chondrocytes
appear like stack of coins
cells actively divide to form isogenic groups

Question 33

describe zone of hypertrophy (layers of epiphyseal plate)

Answer 33

swelling chondrocytes
cells become hypertrophic
cartilage in between isogenic groups is calcified

Question 34

describe zone of cell death (layers of epiphyseal plate)

Answer 34

dying chondrocytes
cells die
can be noticed due to irregular nuclei and lacunae without cells visible

Question 35

describe zone of mixed spicules (layers of epiphyseal plate)

Answer 35

no chondrocytes (eliminated in cell death layer) - some bone cells
calcified cartilage surrounded by bone - mixed
any cells surrounded by matrix = osteocytes

Question 36

describe what happens to bone (secrete/breakdown) in mixed spicules layer of epiphyseal plates

Answer 36

bone is secreted by osteoblasts found at surface - bone here is woven
bone may be reabsorbed by osteoclasts or become anchored to side of the current bone