Bone and Joint Structure

Question 1

What cells are in charge of creating bone?

Answer 1

osteoblasts

Question 2

What do osteoblasts connect with to form the bone fluid barrier?

Answer 2

osteocytes

Question 3

What does the bone fluid barrier regulate?

Answer 3

minute-to-minute Ca flux

Question 4

Where are osteocytes located?

Answer 4

in lacunae

Question 5

What are osteoclasts?

Answer 5

bone removing cells

Question 6

Where are osteoclasts located?

Answer 6

Howeship’s lacuna

Question 7

What do osteoclasts attach to?

Answer 7

mineralized bone

Question 8

How do osteoclasts resorb bone?

Answer 8

they secrete H+ to dissolve mineral and secrete metalloproteinases to break down the organic matrix

Question 9

What type of collagen is the organic matrix made out of?

Answer 9

type 1 collagen

Question 10

What is the purpose of type 1 collagen in the organic matrix?

Answer 10

it provides tensile strength and flexibility

Question 11

What are the non-collagenous parts of the organic matrix?

Answer 11

various cytokines, adhesion molecules, and enzymes

Question 12

What type of mineral is the initial deposition of mineral in bone?

Answer 12

amorphous calcium phosphate

Question 13

What is hydroxyapatine?

Answer 13

crystalline calcium phosphate - the dominant mineral in mature bone

Question 14

What part of bone stores calcium and phosphorus?

Answer 14

the mineral part

Question 15

Identify this structure:

Answer 15

epiphysis

Question 16

Identify this structure:

Answer 16

physis

Question 17

Identify this structure:

Answer 17

metaphysis

Question 18

Identify this structure:

Answer 18

Articular cartilage

Question 19

Identify this structure:

Answer 19

diaphysis

Question 20

Identify this structure:

Answer 20

cortical bone

Question 21

Identify this structure:

Answer 21

trabecular bone

Question 22

Identify this structure:

Answer 22

periostium

Question 23

Identify these structures:

Answer 23

osteons

Question 24

Identify this region:

Answer 24

periostium

Question 25

Identify these structures:

Answer 25

Haversian Canals

Question 26

Identify this structure:

Answer 26

osteocytes

Question 27

Identify this structure:

Answer 27

osteoblasts

Question 28

Identify this structure:

Answer 28

cartilage

Question 29

Identify this structure:

Answer 29

osteoclast

Question 30

What is endochondrial ossification?

Answer 30

when bone forms in and replaces a cartilage model

Question 31

What is required for normal chondrocyte growth?

Answer 31

growth hormone, insulin-like growth factors, thyroxine, and vitamin D3 metabolites

Question 32

How many centers of ossification are there and what are they called?

Answer 32

2 - primary and secondary

Question 33

Where does intramembranous ossification occur?

Answer 33

within fibrous tissue

Question 34

What does woven bone turn into?

Answer 34

lamellar bone

Question 35

What is woven bone?

Answer 35

temporary ragged and rough bone that is rapidly produced at bone at sites of periosteal injury

Question 36

What is lamellar bone?

Answer 36

dense, well organized sheets of bone

Question 37

When is lamellar bone produced?

Answer 37

during normal bone growth and remodeling throughout life

Question 38

How is does bone compression stimulate bone growth?

Answer 38

mineral is distorted which creates piezoelectric activity which stimulates bone growth

Question 39

What are the layers of the joint capsule?

Answer 39

fibrous, loose fibrovascular, and synoviocyte

Question 40

What are the types of synoviocytes?

Answer 40

type a and b

Question 41

What are type a synoviocytes and what do they do?

Answer 41

they are macrophage-like cells that are phagocytic, produce cytokines and inflamatory mediators

Question 42

What are type b synoviocytes and what do they do?

Answer 42

they are fibroblast-like cells that produce hyaluronic acid and lubricin which is added to synovial fluid

Question 43

Which layer of the joint capsule does not have a basement membrane?

Answer 43

the synoviocyte layer

Question 44

What is articular cartilage made up of?

Answer 44

chondrocytes, collagen matrix, proteoglycan/GAG matrix, and water

Question 45

What is the life-span of chondrocytes?

Answer 45

they are long-lived cells

Question 46

What is the function of chondrocytes?

Answer 46

they have the enzymes (matrix metalloproteinases) that are able to produce and degrade matrix

Question 47

What type of collagen is articular cartilage made out of and what is the function?

Answer 47

type II and IX to provie tensile/structural strength

Question 48

What is the proteoglycan/GAG matrix made up of?

Answer 48

core protein with chondroitin SO4 side chains, hyaluronic acid, and hydrated gel

Question 49

What is synovial fluid made up of?

Answer 49

ultrafiltrate, hyaluronic acid, and glycoproteins

Question 50

What is the purpose of synovial fluid?

Answer 50

it is boundary lubricant and serves as a nutritional source for chondrocytes

Question 51

When does squeeze film lubrication come into play and how does it work?

Answer 51

during joing compression and release; compression on the cartilage squeezes fluid to the surface and opposing surfaces ride on fluid film. Release from compression and the fluid is sucked back into the cartilage

Question 52

What is the function of the nutritional pump?

Answer 52

it pumps out wastes and pumps in nutrients in the joint