Bone Histo - Nbde I

Front 1

What are the 4 regions of long bones?

Back 1

1. Diaphysis
2. Epiphysis
3. Epiphyseal plate/disc (growth plate)
4. Metaphysis

Front 2

Which end is the articular end of the bone?

Back 2

Epiphysis

Front 3

Which region of the bone is the transitional area between diaphysis & epiphyseal plate?

Back 3

Metaphysis

Front 4

The shaft of the bone is also known as?

Back 4

Diaphysis

Front 5

Growth region between diaphysis & epiphysis is known as?

Back 5

Epiphyseal plate

Front 6

Organic component of bone is what percentage?

Back 6

35%

Front 7

What accounts for 80-90% organic component of bone matrix?

Back 7

Type I collagen

Front 8

Which glycosaminoglycans are present in organic matrix of bone?

Back 8

CHondroiton sulfate & keratan sulfate

Front 9

Which glycoproteins are present in organic matrix of bone?

Back 9

1. Osteocalcin
2. Osteonectin
3. Osteopontin
4. Bone sialoprotein

Front 10

Osteogenic (osteoprogenitor) cells are found where?

Back 10

Deepest layer of periosteum & endosteum

Front 11

Osteoprogenitor cells are derived from which embryonic tissue?

Back 11

Mesenchyme

Front 12

On what surfaces of bone are osteoblasts found?

Back 12

Periosteal & endosteal surfaces

Front 13

Osteoblasts communicate by?

Back 13

Gap junctions

Front 14

Osteoblasts contain large amounts of rough ER & have a large golgi apparatus why?

Back 14

Primary role of osteoblasts = secrete bone matrix

Front 15

When does an osteoblast become an osteocyte?

Back 15

Once the osteoblast surrounds itself w/ matrix it becomes an osteocyte

Front 16

What is the main role of osteocytes?

Back 16

Maintain bone matrix & mechanotransduction

Front 17

Which type of bone cell are large multinucleated cells?

Back 17

Osteoclasts

Front 18

How are osteoclasts attached to bone?

Back 18

Osteoclasts attach to bone by sealing zone "Clear zone"

Front 19

Rank receptor is located on which cells?

Back 19

Osteoclast precursor cells

Front 20

What must take place in order for osteoclast precursor cell to differentiate into active osteoclast?

Back 20

Rank receptor must bind Rank ligand

Front 21

What are the types of bone?

Back 21

1. Compact bone
2. Spongy bone

Front 22

Which type of bone is laid down in haversian systems (osteons)?

Back 22

Compact bone

Front 23

What are osteons (haversian systems)

Back 23

Series of concentric lamellae w/ a canal containing blood vessels & nerves in center

Front 24

What are the 3 types of lamellae?

Back 24

1. Haversian (concentric)- form osteon
2. Interstitial- between osteons
3. Circumferential- arounds outside & inside of bone

Front 25

Bone is laid down from outside to in or inside out?

Back 25

Bone build from outside to inside

Front 26

What is the connective tissue covering of bone called?

Back 26

Periosteum
-Fibrous layer
-Osteogenic layer

Front 27

What is the inner surface of bone lining the marrow cavity called?

Back 27

Endosteum

Front 28

What is found in the endosteum?

Back 28

Active osteoblasts & osteoclasts

Front 29

How do trabeculae strengthen bone?

Back 29

Diffuse stresses on bone

Front 30

The periosteum of the skull is called?

Back 30

Pericranium

Front 31

Bones of skull have 2 external bony tables separated by spongy bone called?

Back 31

Diploic bone

Front 32

Which type of marrow consists of developing blood cells, contains reticular cells & fibers and has abudant sinusoids?

Back 32

Red marrow

Front 33

Which type of marrow has adipose tissue found within medullary cavtiy?

Back 33

Yellow marrow

Front 34

What are sharpey's fibers?

Back 34

Collagen fibers from periosteum or from tendons/ligaments that become embedded in bone matrix

Front 35

Which vitamins are essential to healthy bone?

Back 35

1. Vit C- collagen
2. Bit D

Front 36

Calcitonin is secreted by?

Back 36

Thyroid gland

Front 37

Which hormone inhibits osteoclast activity & promotes urinary excretion of calcium & phosphate?

Back 37

Calcitonin

Front 38

Which hormone stimulates bone resorption & elevates blood calcium levels?

Back 38

PTH

Front 39

How does intramembranous bone formation occur?

Back 39

-Osteoblats produce small bony spicules
-Bony spicules fuse to form larger bone tissue
-Bone is then remodeled by osteoclasts & osteoblasts

Front 40

Where does periosteal bony collar form in Endochondral bone formation?

Back 40

Diaphysis

Front 41

When does the marrow cavity begin to form in endochondral bone formation?

Back 41

Once cartilage is calcified in diaphysis -- blood vessels & CT invade & marrow cavity begins forming

Front 42

Where do secondary centers of ossificiation form in endochondral bone formation?

Back 42

Epiphyses

Front 43

A layer of hyaline cartilage remains where during endochondral bone formation?

Back 43

Between epiphysis & diaphysis-- forms epiphyseal disc

Front 44

What are the 5 zones of cartilage forming the epiphyseal disc?

Back 44

1. Quiescent or reserve zone
2. Proliferative zone
3. Zone of maturation or hypertorphy
4. Zone of calcification
5. Zone of ossificiation

Front 45

In which zone of epiphyseal disc are chondrocytes not actively dividing or producing matrix?

Back 45

Quiescent or reserve zone

Front 46

In which zone of epiphyseal disc are cells undering mitoses & line up in colums?

Back 46

Proliferative zone

Front 47

In which zone do cells become very large & full of glycogen-- matrix is compressed into narrow bands between columns of cells?

Back 47

Zone of maturation or hypertrophy

Front 48

In which zone do cells die & cartilage matrix becomes calcified?

Back 48

Zone of calcification

Front 49

In which zone is bone laid down on spicules of calcified cartilage & bone is then remodeled?

Back 49

Zone of ossification

Front 50

What happens when bone is done growing in length?

Back 50

Epiphyseal disc becomes ossified --> no further growth possible

Front 51

What is the function of periosteal osteoblasts when bone grows in diameter?

Back 51

Periosteal osteoblasts lay new bone appositionally --> increasing bone diameter

Front 52

What is the function of endosteal osteaoblasts in bone growth in diameter?

Back 52

Endosteal osteoclasts resorb bone --> Increase size of marrow cavity

Front 53

What are secondary ossification centers?

Back 53

After initial bone formation by endochondral ossification --> other parts of cartilage model begin to ossifiy

Front 54

Which type of bone has abundant osteocytes & irregularly arranged collagen fibers?

Back 54

Primary (immature, woven) bone

Front 55

Which type of bone is lamellar, osteocytes less abundunt & more evening spaced & collagen fibers parallel w/ in lamella?

Back 55

Secondary (mature) bone