Histology of Cartilage and Bone Flashcards Preview

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Flashcards in Histology of Cartilage and Bone Deck (83):
1

What do mesenchymal condensations do?

Generate cartilage and bone

2

Mesenchymal condensations in the embryo predict the location of the future

Skeletal system

3

Mesenchymal condensations can generate cartilage or bone. What determines their fate?

Proximity to vascularity

4

Condensations that arise in avascular parts of the embryo form

Cartilage

5

Condensations that arise in vascular parts of the embryo form

Bone

6

What is a more likely fate, that condensations form cartilage or bone?

Cartilage

7

Some embryonic cartilage remains cartilage, but most is transiently replaced by

Bone (does not become bone though)

8

Cells of condensation give rise to a type of cell that begins to make the ECM, called

Chondroblasts

9

Chondroblasts that get trapped in the ECM are called

Chondrocytes

10

Forms outer border of most cartilage

-Generates new chondroblasts around the perimeter of the forming cartilage

Perichondrium

11

New chondroblasts generated by perichondrium lead to appositional growth around the

Perimeter

12

What are the two distinct layers of the perichondrium?

1.) Fibroblastic (outermost layer)
2.) Chondrogenic

13

Chondrocytes retain the ability to divide and generate

-bone can't do this

Isogenous groups (clusters)

14

Grows from within (interstitial) and without (appositional)

Cartilage

15

Avascular and contains chondrocytes in lacunae

Cartilage

16

Cartilage is made up of which type of collagen?

Type II

17

What are the three types of cartilage?

Hyaline, Elastic, and Fibro

18

Hyaline cartilage is located in the

Nasal, laryngeal, tracheal, and articular regions

19

Articular hyaline cartilage has no

Perichondrium

20

Where is elastic cartilage found?

Ear, eustacian, and eppiglottis

21

A special feature of elastic cartilage is that it contains

Elastic fibers (requires a special stain)

22

Where is fibrocartilage located?

Symphyses, intervertebral disks, and menisci

23

Fibro cartilage is intermixxed with

Dense CT (no perichondrium)

24

Chondrocytes are secretory cells and are distinguished by

Lots of RER and prominent golgi

25

Stained with basophilic staining and is located right around the edge of chondrocytes

Territorial matrix

26

Acidophilic staining in the area between chondrocytes

Interterritorial matrix

27

Caps the bone at moveable joints

Articular cartilage

28

Articular cartilage is susceptible to osteoarthritis because it lacks a

-the reason it is ill equipped to initiate repair

Perichondrium

29

Erosion of the articular cartilage in osteoarthritis results in diminution or disappearance of the

Joint space of X-Ray

30

Made up of a delicate synovial inner layer and a tough fibrous outer layer

Joint capsule

31

Joints are discontinuous epitheliod intima with no tight junctions or a basement membrane. They are leaky and are comprised of

Loose CT and many vessels

32

Causes influx of immune cells into the synovium, which results in destruction of the joint

Rheumatoid arthritis

33

Is radiolucent, i.e. why we can't see ears on an X-ray

Elastic cartilage

34

The annulus fibrosis is made up of

Fibrocartilage

35

Fibrocartilage is made up of which type of collagen?

Type I

36

Bone can form in two ways. Is the final product different depending on the mechanism?

No

37

Bone formation used for bones with a complex shape where a cartilage model is laid down first and then replced by bone

Endochondral bone formation

38

What are the two ways the bone can form?

1.) Endochondral (complex shape)
2.) Intramembranous (flat bones)

39

Some of the flat bones of the face and skull develop via the

Intramembranous route

40

Generates osteoblasts

Periosteum

41

Prominent in developing bone

Osteoblasts

42

Osteoblasts trapped in the matrix become

Osteocytes

43

The matrix of bone is primarily

Type I collagen

44

The unmineralized bone matrix is called the

Osteoid

45

Mineralization (CaPO4) of the osteoid yields

Bone

46

Membranous bone enlarges only through

Appositional growth

47

The calcified matrix of bone is less than 10% H2O so the diffusion of nutrients and waste removal is

Poor

48

To fix this, each osteocyte sits in an unmineralized

Lacunae

49

The lacunae are connected to neighbors and blood supply by processes and

Gap junctions

50

Processes, nutrients, and wastes pass through tunnels in the bone matrix called

Canaliculi

51

Has appositional and interstitial growth

Cartilage

52

Has appositional growth only

Bone

53

Employs a transient cartilage scaffold that is ultimately replaced by bone

Endochondral Bone

54

Takes advantage of cartilage's interstitial growth to creae complex shapes and lengthen bone

Endochondral bone formation

55

Exist as a bone/cartilage hybrid from prenatal development to early adulthood

Most long bones

56

Endochondral chondrocyte life cycles overlap, with those furthest from the resting zone being the most

Advanced

57

Endochondral zones are maintained at the

Growth plate

58

In endochronal bone formation, the initial bone product is

-highly cellular and disorganized

Poor quality (woven bone)

59

Soon after the initial bone is formed, osteoblasts and osteoclasts remodel the bone, forming

Lamellar bone

60

Has fewer osteocytes and is highly organized

Lamellar bone

61

A multinucleate bone destroyer that plays an essential role in bone maturation, remodeling, repair, and Ca2+ balance

Osteoclasts

62

What do osteoclasts make to
1.) Dissolve minerals
2.) Degrade collagen

1.) HCL
2.) Cathepsin K

63

The divot osteoclasts make when breaking down bone is called

Howships Lacunae

64

Covers the hollowships lacunae

-new osteoblasts are generated and new bone is produced

Endosteum (analogous to periosteum)

65

Spongy bone is in contact with blood supply and the trabeculae are lined with

Endosteum

66

Compact bone has a system of channels called

Volkmann Canals and Haversian canals

67

To remodel, osteoclasts invade compact bone and create a perpendicular tunnel called a

Volkmann canal

68

Then, what enters into the volkmann canal?

Endosteum and blood vessels

69

Osteoclasts then change direction and continue through the long axis of bone creating

Haversian Canal

70

The Haversian canal is then lined with endosteum that initiates the

Rebuild and repair process

71

Generates osteoblasts on outer aspect (bone side)

Endosteum

72

Produce concentric layers of new bone and push the endosteum toward the center of the canal

Osteoblasts and osteocytes

73

This process continues until the Haversian canal is nearly obliterated by

New bone formation

74

Occupy the center of the remaining canal

Vessels and nerves

75

New bone is populated by osteocytes in their lacunae, connected via processes through canaliculi in the matrix. The whole structure is called the

Osteon

76

In the process of creating a new osteon, and old one is

Destroyed

77

Remnants of an old osteon lost to the remodeling process

Interstitial lamellae

78

Defines the outer edge of each osteon

Cement line

79

The advantage in bone thickness you get from exercising will disappear after

20 years of inactivity

80

Imbalance between bone reabsorption and bone production

-affects primary trabecular bone

Osteoporosis

81

Osteoporosis is probably due to diminished osteoblast activity, but most treatments target

Osteoclasts

82

A discontinuous epithelial intima with no tight junctions or basal membrane

-Very leaky

Synnovial inner layer

83

What are the two layers of a joint capsule?

1.) Delicate synovial inner layer
2.) Tough fibrous outer layer

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