Histology of Bone and Cartilage Flashcards
1
Q
Is cartilage vascular?
A
No it is avascular
2
Q
Cartilage has […] ability to repair when damaged.
A
Limited
3
Q
A
4
Q
A
5
Q
A
6
Q
Where is hyaline cartilage located?
A
- Joints (articular surfaces)
- Trachea and bronchi
- Ribs
- Epiphyseal plate
7
Q
What type of cartilage is this?
A
Hyaline
8
Q
What is the purpose of the perichondrium in cartilage?
A
Perichondrium protects the underlying cartilage, and is a source of progenitor cells (Chondroblasts)
9
Q
What is interstitial growth of cartilage?
A
Chondrocytes within the cartilage divide
to form isogenous groups
10
Q
What is appositional growth of cartilage?
A
Chondroblasts in the cellular perichondrium divide and differentiate into chondrocytes
11
Q
Type 2 collagen is found predominantly in […]
A
Cartilage
12
Q
Type 1 collagen is found predominantly in […]
A
Bone
13
Q
What is the most abundant substance in the extracellular matrix of hyaline cartilage?
A
Water
14
Q
A
15
Q
Articular cartilage is a particular type of hyaline cartilage. It lacks a specific structure that is commonly found in hyaline cartilage. What is this structure?
A
Perichondrium
16
Q
A
17
Q
Where is elastic cartilage located?
A
- Epiglottis
- External ear
- Wall of the external acoustic meatus
- Eustachian tube
18
Q
What type of cartilage is shown (hyaline, elastic, fibrocartilage)
A
Elastic
19
Q
Where is fibrocartilage located?
A
- Pubic symphysis
- Intervertebral discs
- Meniscus of the knee
20
Q
Does fibrocartilage have a perichondrium?
A
No
21
Q
What is the function of hyaline cartilage?
A
- Resists compression
- Provides cushioning and low friction surface in joints
- Structural support (e.g. trachea and bronchi)
- Foundation of fetal skeleton and endochondral bone formation
22
Q
What is the function of elastic cartilage?
A
Flexible support for soft tissues
23
Q
What is the function of fibrocartilage?
A
Resists deformation under stress
24
Q
What are the main cells found in:
- Hyaline
- Elastic
- Fibrocartilage
A
- Chondrocytes and Chondroblasts
- Chondrocytes and Chondroblasts
- Chondroytes and Fibroblasts
25
Most collagen in cartilage is type 2. Fibrocartilage is an exception, because it has both type 2 and type [...] cartilage in ECM.
1
26
What are the 2 types of bone formation?
* Endochondral – bone formed from a cartilage model (most bones of the body)
* Membranous – bone formed from mesenchymal cells (bones of the skull, face, mandible and clavicles)
27
What are the 3 types of bone?
* Cortical
* Trabecular
* Immature/woven
28
What is an osteoprogenitor cell?
Derived from mesenchymal cells and are located in the outer (periosteum) and inner (endosteum) tissues that cover bone. They give rise to osteoblasts.
29
What is an osteoblast?
Derived from osteoprogenitor cells, and are located on the surface of bone (periosteal and endosteal). They secrete the extracellular matrix (osteoid), and are responsible for its subsequent calcification.
30
What is an osteocyte?
Derived from osteoblasts, and are located in lucanae within the calcified matrix. They are essential for the viability of bone, respond to mechanical stress on bone, and are involved in Ca++ and Pi homeostasis.
31
What is an osteoclast?
Derived from granulocyte/monocyte progenitor cells in the bone marrow. They are large multinucleated cells that sit on the surface of bone where they resorb bone.
32
What are bone lining cells?
Thought to be quiescent osteoblasts. They are located on the outer (periosteal) and inner (endosteal) surface of bone. Thought to be involved in the nutritional support of osteocytes and involved in the movement of Ca++ and Pi into and out of bone.
33
34
35
Type [...], and to a lesser extent type [...], collagen is the major component of the extracellular matrix. Provides [...] strength.
1; 5; tensile
36
What is the purpose of proteoglycan molecules in bone?
Glycosaminoglycans such as hyaluronan, chondroitin sulfate and keratin sulfate contribute to the compressive strength of bone, also bind growth factors
37
What is the purpose of Multiadhesive Glycoproteins in bone?
Involved in mineralization and attachment of bone cells to the matrix (e.g., osteonectin, osteopontin)
38
What si the purpose of Bone-Specific, Vitamin K+-Dependent Proteins in bone?
Involved in mineralization, and attracts and stimulates osteoclasts
39
What is osteocalcin?
Osteocalcin is released into the circulation during bone resorption, and is used as a marker of bone turnover
40
What is the purpose of Growth Factors and Cytokines found in bone tissue?
Regulate the function of osteoblasts (e.g., Bone Morphogenetic Protein [BMP-7]).
41
What is BMP7?
R-BMP-7 is used to stimulate bone growth following bone surgery or bone grafting
42
Prior to puberty the [...] line is comprised of[...] cartilage (epiphyseal plate) and is responsible for bone [...].
epiphyseal
hyaline
elongation
43
44
What type of bone is this?
Label all structures.
Compact bone
45
46
Older lamellae are found on the [...] of the osteon.
Periphery
47
48
* What type of bone is shown?
* Does this type of bone have osteons? Lamellae?
* Trabecular bone
* No; Yes
49
50
* What type of bone is shown?
* Does it have osteons? Lamellae?
* Woven bone
* No; No
51
The majority of bones in the body are formed by an [...] process. Ossification begins [...].
Endochondral
in utero
52
Describe (in general) the process of intramembranous bone formation?
53
54
Matrix of hyaline cartilage has the appearance of [...]
Ground glass
55
Isogenous groups represent [...] chondrocytes. This is termed “[...] growth”.
Dividing
Interstitial
56
57
Describe the structure of the perichondrium and why it is so important.
The perichondrium consists of an outer fibrous layer and an inner cellular layer. The cellular layer contains progenitor cells that will differentiate into chondrocytes. This allows for replacement of damaged cartilage as well as appositional growth of the cartilage. This is why articular cartilage and fibrocartilage are unable to repair any damage due to lack of this structure.
58
What type of cartilage is shown?
What structures are shown in the cartilage?
Hyaline cartilage
Cellular and fibrous layers of perichondrium
59
What type of cartilage is shown?
Label the structures.
Elastic cartilage
60
What type of cartilage is shown?
Label the structures.
Fibrocartilage
61
62
What cells are found on the periosteum and endosteum?
* Progenitor cells
* Osteoblasts (bone forming cells)
* Osteoclasts (bone resorbing cells)
* Bone lining cells (endosteal cells)
63
[...] are multinucleated bone cells.
Osteoclasts
64
65
66
67
What type of bone growth is shown in this image?
Endochondral
68
What type of bone growth is shown in this image?
Intramembranous
69
What type of bone is shown in this image?
Woven bone
70
71
Desribe the process of interstitial growth that isogenous groups of chondrocytes undergo.
Mesenchymal cells aggregate into closely knit clusters and differentiate into chondroblasts. These cells secrete collagen and mucopolysaccharide matrix containing chondroitin sulfate. The matrix secretion causes the chondroblasts to be pushed apart. As this occurs, the cartilage cells undergo divisions. This results in small clusters of chondroblasts within the developing matrix which also start to secrete matrix and be pushed away from each other. This sort of growth of cartilage is termed interstitial growth due to the fact that the extracellular matrix is secreted into spaces between the cells.
72
What is/are the primary types(s) of collagen found in fibrocartilage?
Fibrocartilage is primarily composed of type I collagen
73
74
Fibrocartilage is primarily adapted to withstand which type of force(s)?
Tension - Fibrocartilage is designed to maintain the integrity between long bones and resists forces that attempt to separate two bones
75
Describe the processes osteoclasts use to resorb bone.
Osteoclasts release hydrolytic enzymes to break down the collagen. They secrete acids to break down the hydroxyapatite crystals. Calcium and phosphate are released into the blood.
76
In the epiphyseal plate of bones, cells that are in the zone of proliferation are secreting which type(s) of collagen?
Type 2 and Type 11
77
In epiphyseal plates of bones, cells that are in the zone of hypertrophy contain rather clear cytoplasm due to large accumulations of what substance?
Glycogen
78
In epiphyseal plates of bones, cells in the zone of hypertrophy start to secrete which unique type of collagen?
Type 1
79
In epiphyseal plates of bones, what is a substance secreted by hypertrophied chondrocytes which promotes invasion of blood vessels into calcified cartilage matrix?
VEGF
80
The irregular channels and grooves at the outer border of the bone are most likely destined to become what structure(s)?
Compact bone
