histology 3- bone

Question 1

functions of bone

Answer 1

protection
support
mechanical basis for movement
storage
blood cell formation

Question 2

blood cell formation happens where and is called what

Answer 2

in red bone marrow. hematopoiesis

Question 3

storage function of bone

Answer 3

stores minerals. calcium, phosphate. yellow marrow store triglycerides.

Question 4

classification of bone

Answer 4

long
short
flat 
irregular
seasmoid

Question 5

long bone location

Answer 5

femur, shaft portions and 2 ends, longer than wide.

Question 6

short bone location

Answer 6

carpal and tarsal bones in wrist and ankles.

Question 7

flat bone locatoin

Answer 7

very thin, plate like. sternum, ribs, scapula, skull bones

Question 8

irregular bone locatoin

Answer 8

very complicated shape. pelvis, vertebrae

Question 9

sesamoid bone locatoin

Answer 9

almost cube shape, very specific. form in tendon. largest is patella.

Question 10

gross observation of bone tissue

Answer 10

compact

spongy- has trabeculae

Question 11

long bone structure

Answer 11

epiphysis
metaphysis
diaphysis of shaft.

Question 12

epiphysis

Answer 12

on ends of long bone. compact bone on outside, spongy bone on inside- spicules look random but are very particular.

Question 13

during growth the epiphysis and metaphysis are separated by what

Answer 13

growth plate. (epiphyseal plate).

Question 14

in adults, radiographs identify growth plate as what

Answer 14

epiphyseal line.

Question 15

epiphyseal plate is responsible for what

Answer 15

lengthening of the long bone.

Question 16

epiphyseal plate is made of what and is replaced by what after puberty

Answer 16

hyalin cartilage. replaced with bone. bone is done growing.

Question 17

diaphysis

Answer 17

compact bone on outside, marrow on inside.

contains red/yellow marrow. as we age red turns to yellow marrow

Question 18

periosteum

Answer 18

• covers outer surface of bone
• where muscle/tendon/ligament attaches
• vascularized
• contains osteoprogenitor cells.

Question 19

2 layers of periosteum

Answer 19

outer fiber layer- dense connective tissue
inner osteogenic (cellular) layer.

Question 20

endosteum

Answer 20

lines marrow cavity.

consists of cells that belong to the stroma of the marrow or are derived from resting osteoblast

Question 21

sharpys fibers

Answer 21

connect periosteum to bone. transfers force from muscle contraction.

Question 22

short, flat, sesamoid, irregular bone structure

Answer 22

(layers) compact bone, dipole (spongy), compact bone.

Question 23

bone composition (2)

Answer 23

cells
extracellular matrix (ECM)

Question 24

cells of bone

Answer 24

osteogenic cell- mesenchymal kind of cells
osteoblast- make osteocytes
osteocyte
osteoclast- very large

Question 25

ECM of bone

Answer 25

organic- osteoid | inorganic- hydroxyapatite crystals

Question 26

ECM- osteoid contains what

Answer 26

- type one collagen fibers - bone matrix proteins (BMP) - glycoproteins - osteocalsin - osteonectin

Question 27

what lays down layer of osteoid

Answer 27

osteoblast

Question 28

what do BMP's contain

Answer 28

GAG's

Question 29

what is osteocalsin

Answer 29

- vitamin K dependent polypeptide. - produced by osteoblast - important in promoting calcification of matrix giving us inorganic portion

Question 30

what helps give bones its inorganic (HA) portion.

Answer 30

osteocalsin

Question 31

what is responsible for hardness and resilience of bones?

Answer 31

HA crystals. (50% of dry weight).

Question 32

osteogenic cell

Answer 32

- develop into osteoblast - basically mesenchymal stem cells - found in inner layers of periosteum or endosteum

Question 33

osteoblast main function

Answer 33

produce osteoid (bone matrix)- signal for calcification of the bone

Question 34

osteoblast structure and location

Answer 34

find on surface of bone matrix, right on interchange between matrix and periosteum. endosteum when very active line up right next to each other, looks like epithelial, get larger when producing matrix

Question 35

osteoblast stain what and contain lots of what in their cells

Answer 35

basophilic, love hematoxylin. rough ER, golgi, ribosomes

Question 36

when osteoblast are completely surrounded by matrix they are called what and sit in what

Answer 36

osteocytes, sit in lacunae

Question 37

osteocyte main function

Answer 37

maintain matrix.

Question 38

osteocytes sit in what

Answer 38

lacunae- completely surrounded by calcified matrix

Question 39

how long to osteocytes live

Answer 39

a long time

Question 40

how to osteocytes exchange materials (waste/get nutrients from blood)

Answer 40

they have cytoplasmic extensions that sit in canals

Question 41

what are the canals called that have osteocyte cytoplasmic extensions in them

Answer 41

canilculi

Question 42

how to osteocytes in the middle get nutrients and get rid of waste

Answer 42

sends out little cytoplasmic extension before its completely surrounded and calcified. at end of cytoplasmic extensions has gap junctions to another which eventually one is near a blood vessels. so pass on from one osteocyte cytoplasmic extension to another. extensions sit in canals in the bone. canals called caniliculi.

Question 43

osteoclast main function

Answer 43

reabsorb bone

Question 44

osteoclast characteristic

Answer 44

large, motile, multinucleate.

Question 45

osteoclast are derived from what

Answer 45

same cells that make macrophages

Question 46

part of osteoclast they do their reabsorption

Answer 46

ruffled boarder

Question 47

ruffled boarder

Answer 47

invagination of plasma membrane, increases surface area, lots of protein pumps in that area. low pH.

Question 48

area where reabsorption takes place

Answer 48

reabsorption bay, (howship lacunae) a little depression.

Question 49

bone stains what color because of what

Answer 49

pink, lots of collagen

Question 50

how is HA formed in bone?

Answer 50

1. osteoid starts secreting substances that bind calcium 2. osteoblast secret vesicles that contain alkaline phosphatase. 3. calcium and alkaline phosphatase get together and start forming HA crystals

Question 51

two types of bone tissue

Answer 51

1. primary bone tissue (woven or immature bone) | 2. secondary bone tissue (lamellar bone or mature)

Question 52

primary bone

Answer 52

- not organized - lots of cells - first bone to develop in embryo - bone to repair breaks - replaced by mature bone

Question 53

secondary bone

Answer 53

- much more organized. - osteon -

Question 54

main structural unit of compact bone

Answer 54

osteon

Question 55

another name for osteon

Answer 55

haversian system

Question 56

osteon arrangement

Answer 56

like straws inside bigger straws. lamellae fibers alternate 90 degree pattern. this is what makes bones so strong

Question 57

middle of osteon is what

Answer 57

a canal, called haversian canal or central canal. where arteries, veins, and nerves are.

Question 58

about how many lamellae make up osteons

Answer 58

4-8, not any more than 10 because inside ones couldn't get nutrients, it would be too hard.

Question 59

whats in between osteons

Answer 59

interstitial lamellae

Question 60

interstitial lamellae

Answer 60

made up of old osteocytes. part of build up break down cycle.

Question 61

what is the final layer that surrounds osteons

Answer 61

cement line

Question 62

lamellae that line medullary cavity

Answer 62

inner circumferentrial

Question 63

volkmann's canal

Answer 63

runs 90 degree, allows for access to outside of bone or do medullary cavity. connect blood vessels to endosteum. nutrients come from middle medullary cavity, waste to outward.