Bone Flashcards Preview

Year 1 Cell Biology > Bone > Flashcards

Flashcards in Bone Deck (83):
1

Pressure applied to bone induces what type of remodeling?

Resorption

2

Tension applied to bone induces what type of remodeling?

Deposition

3

What are the epiphyses?

Ends of bones

4

What are the metaphyses?

Angulation between epiphysis and diaphysis

5

What are the diaphyses?

Shaft of bone

6

What is the periosteum?

External connective tissue capsule of bone

7

What layers are present in active (growing) periosteum?

1. Outer fibrous layer2. Inner cellular layer

8

What layers are present in inactive (mature) periosteum?

Only well-developed outer fibrous layer

9

How is the fibrous layer of periosteum anchored to the bone?

Sharpey's fibers

10

What are Sharpey's fibers?

Bundles of collagenous fibers; anchor fibrous periosteum to bone

11

In the inner cellular layer of periosteum, what cells are present in a growing bone?

Osteoprogenitor cells

12

In the inner cellular layer of periosteum, what cells are present in a non-growing bone?

Periosteal cells

13

Does periosteum cover the bone at articular surfaces?

No

14

Does periosteum cover the bone where tendons attach?

No

15

What is the endosteum?

Internal connective tissue capsule of bone

16

What makes up the endosteum?

Thin layer with single row of osteoprogenitor cells

17

Endosteum lines what compartments within bone?

1. Bone marrow cavity2. Haversian and Volkman canals3. Spicules and trabeculae

18

What gives bones their hardness?

Inorganic minerals

19

What are the inorganic components of bone?

1. Hydroxyapatite crystals (calcium phosphate)2. Bicarbonate, citrate, magnesium, sodium, potassium

20

What makes up the organic component of bone?

1. Fibers2. Ground substance

21

What is the function of the organic component of bone?

Prevents brittleness

22

What is the main type of collagen in the organic component of bone?

Type I

23

What are the components of the ground substance in bone?

1. Proteoglycans2. Multiadhesive glycoproteins3. Bone-specific, Vitamin K dependent proteins4. Growth factors and cytokines

24

What is the function of proteoglycan side chains in the ground substance of bone?

Binding growth factors

25

What binds growth factors in the ground substance of bone?

Proteoglycan side chains

26

What are the multiadhesive glycoproteins in the ground substance of bone?

1. Osteonectin2. Sialoproteins

27

What is the function of osteonectin?

Serves as glue between collagen and hydroxyapatite crystals

28

What serves as glue between collagen and hydroxyapatite crystals?

Osteonectin

29

What are the sialoproteins?

1. Osteopontin2. Sialoproteins I and II

30

What is the function of osteopontin?

Binds cells to bone matrix

31

What binds cells to bone matrix?

Osteopontin

32

What are the functions of sialoproteins I and II?

1. Bind cells to bone matrix2. Begins calcium phosphate formation during mineralization

33

What is an example of a bone-specific, Vitamin K dependent protein?

Osteocalcin

34

What is the function of osteocalcin?

1. Traps calcium from blood2. Stimulates osteoclasts to remodel bone

35

What traps calcium from blood and stimulates osteoclasts to remodel bone?

Osteocalcin

36

What are the functions of bone morphogenic proteins (BMPs)?

1. Induce mesenchymal cells to differentiate into osteoblasts2. Used following surgery to stimulate bone formation

37

What induces mesenchymal cells to differentiate into osteoblasts?

BMPs

38

What is used following surgery to stimulate bone formation?

BMPs

39

What is the term for osteoprogenitor cells located in the inner layer of the mature periosteum?

Periosteal cells

40

What is the term for osteoprogenitor cells located in the endosteum?

Endosteal cells

41

Can osteoprogenitor cells undergo mitosis?

Yes

42

In low oxygen tension, what do osteoprogenitor cells differentiate into?

Chondrogenic cells

43

Are osteoprogenitor cells active during bone growth?

Yes

44

What is the cell shape for osteoblasts?

Cuboidal - columnar

45

Are osteoblasts basophilic or acidophilic?

Basophilic

46

What is osteoid?

Newly formed non-mineralized bone ("pre-bone")

47

What is the composition of osteoid?

1. Type I collagen2. BMPs

48

Osteoblasts have high concentrations of what enzyme?

Alkaline phosphatase

49

During bone deposition, is there an increase or decrease in serum alkaline phosphatase levels?

Increase

50

How to osteoblasts communicate with each other?

Gap junctions

51

What are the functions of bone lining cells?

1. Nutritional support of osteocytes2. Uptake and release of calcium and phosphate by bone tissue

52

What is the periosteocytic space?

Space between osteocyte cell membrane and the lacuna and canaliculi

53

Are osteoclasts basophilic or acidophilic?

Acidophilic

54

What causes acidophilic nature of osteoclasts?

Acid-containing lysosomes

55

Osteoclasts are derived from ________________

Mononuclear hematopoietic progenitor cells (CFU-GM)

56

Where are osteoclasts found?

Howship's lacuna

57

What is Howship's lacuna?

Enzymatically-etched shallow depression where osteoclasts are found

58

An osteoclast actively breaking down bone has what morphological characteristics?

1. Ruffled border2. Clear zone 3. Basolateral region

59

What is the function of the clear zone in an active osteoclast?

Sealing zone to isolate corrosive materials

60

The acidic environment of osteoclasts breaks down what component of bone?

Inorganic component

61

What enzyme types break down the organic component of bone?

1. Lysosomal hydrolases2. Metalloproteinases (collagenase, gelatinase)

62

What happens to osteoclasts when they are done with bone resorption?

Apoptosis

63

The diploe found between inner and outer tables of the skull cap is characterized as what type of bone?

Cancellous bone

64

What is the main morphological characteristic of compact bone?

Haversian systems (osteons)

65

What is the main morphological characteristic of cancellous bone?

Bone lamellae (layers)

66

Is primary bone temporary or permanent?

Temporary

67

What is the morphology of primary bone?

Irregular / interlacing bundles of collagen (nonlamellar)

68

What is the morphology of secondary bone?

Parallel or concentric bone lamellae

69

What is the Haversian canal?

Vascular space that encloses a neurovascular bundle, but NOT lymphatic vessels

70

What is the only component of bone that has lymphatic vessels?

Periosteum

71

What are Volkmann canals?

Perforating canals; obliquely oriented; connect osteons that are next to each other

72

Do Volkmann canals have concentric lamellae?

No

73

In what direction to osteons form?

Outside-in

74

Where are inner circumferential lamellae?

Around the marrow cavity

75

What is anklyosis?

Condition in which two articulating bones fuse, obliterating the joint so there is no movement

76

What is the cause of ankylosis?

Trauma to hyaline cartilage which causes it to become calcified and replaced by bone

77

What is rheumatoid arthritis?

Autoimmune disease that attacks synovial joints, damaging articular cartilages

78

What is gouty arthritis?

Caused by accumulation of uric acid crystals

79

Trauma to hyaline cartilage which causes it to become calcified and replaced by bone

Ankylosis

80

Autoimmune disease that attacks synovial joints, damaging articular cartilages

Rheumatoid arthritis

81

Caused by accumulation of uric acid crystals

Gouty arthritis

82

What is rickets?

Disorder resulting from calcium deficiency during development, or from inadequate vitamin D which is necessary for calcium absorption from the GI tract

83

What is osteoporosis?

Condition characterized by reduction in bone mass in both components of bone matrix