Lecture 5: Histology of Cartilage Flashcards
_________ is a semi-rigid tissue comprised of cells and ECM containing collagen and elastic fibers
Cartilage
Describe nerve supply, vascular supply, and lymphatics associated with cartilage
Cartilage has no nerve supply or lymphatics and is avascular
What are some general functions of cartilage?
Supports and withstands deformation, as well as absorbs shock
Reduces friction at joints
Model for bone growth
Fracture repair
____________ are cells that secrete collagen matrix due to mitotic capabilities
Chondroblasts
___________ are mature cartilage cells in lacunae, they are surrounded by and maintain the matrix
Chondrocytes
The cartilage matrix can be separated into what 2 compartments?
Territorial vs. interterritorial matrix
What type of collagen is predominant in cartilage?
Type II collagen
What type of collagen is present in fibrocartilage and outer perichondrium?
Type I collagen
What type of fibers are found in elastic cartilage?
Elastin fibers
The cartilage matrix is made up of fibers like type I collagen, type II collagen, and/or elastin, as well as what other major component?
Ground substance composed of proteoglycans
What are 4 major proteoglycans found in the ground substance component of cartilage?
Hyaluronic acid
Chondroitin sulfate
Keratin sulfate
Aggrecan
What are the 3 major types of cartilage?
Hyaline
Elastic
Fibrocartilage
Which of the following does not have a perichondrium?
A. Hyaline cartilage
B. Fibrocartilage
C. Elastic cartilage
D. All types of cartilage are surrounded by perichondrium
B. Fibrocartilage
What type of cartilage would you find in the external ear, epiglottis, and auditory tube?
Elastic cartilage
What type of cartilage would you find in the intervertebral discs, pubic symphysis, and TMJ?
Fibrocartilage
What type of cartilage would you find in the articular areas, nasal septum, larynx, trachea, bronchi, embryonic development, and ribs?
Hyaline cartilage
Describe hyaline cartilage in terms of presence of a perichondrium and its major type of collagen
Surrounded by a perichondrium
Contains type II collagen
Describe elastic cartilage in terms of presence of a perichondrium and its major type of collagen
Surrounded by perichondrium
Contains type II collagen
Describe fibrocartilage in terms of presence of a perichondrium and its major type of collagen
NO perichondrium!
Contains type I collagen
Although hyaline cartilage is typically surrounded by a perichondrium, what area colonized by hyaline cartilage LACKS this perichondrium?
Articular cartilages lack perichondrium
What type of cartilage is described as amorphous but homogeneous?
Hyaline
What are the 5 zones of developing cartilage during skeleton formation from superficial to deep (epiphyseal plate)?
Zone 1: resting cartilage
Zone 2: proliferating cartilage
Zone 3: hypertrophic cartilage
Zone 4: calcified cartilage
Zone 5: ossification
Which compartment of the cartilage matrix is moderately staining, consists of type II collagen randomly arranged, and is high in GAGs with decreased collagen?
Territorial matrix
What compartment of the cartilage matrix surrounds the territorial matrix, less less intensely staining, contains more collagen II and fewer proteoglycans?
Interterritorial matrix
____________ is the interface of dense regular CT that contains a vascular supply, and applies to hyaline and elastic cartilage only
Perichondrium
What are the 2 layers of perichondrium?
Outer fibrous layer
Inner chondrogenic layer
The outer fibrous layer of perichondrium is the fibroblast layer. What type of collagen does it produce?
Produces type I collagen and elastin
[this is the transitional zone between cartilage and surrounding general CT]
The inner chondrogenic layer of perichondrium differentiates into ____________ and secretes _________ ____ collagen
Chondroblasts
Type II
Fibrocartilage is the intermediate between cartilage and dense fibrous supporting tissue. What type of collagen is associated with fibrocartilage?
Types I and II
How are chondrocytes aligned/oriented in fibrocartilage?
Aligned in the direction of functional stress (columns)
What are the 2 types of growth exhibited by cartilage?
Appositional
Interstitial
What type of growth takes place within the cartilage itself, and overall growth is due to secretion of new matrix?
Interstitial growth
What limits interstitial growth?
The avascular nature of cartilage
The key to interstitial growth is the formation of _________ groups when chondrocytes divide within ________
Isogenous; lacunae
What type of growth forms new cartilage on the surface from pre-existing cartilage?
Appositional growth
Where exactly does appositional growth of cartilage occur?
Within the inner layer of perichondrium
T/F: With appositional growth, chondrogenic cells produce collagen II (found in perichondrium)
False, chondrogenic cells produce collagen I
After appositional growth is initiated, cells become _________ and secrete collagen II and ground substances
Chondroblasts
Cartilage has a modest repair capacity. Injuries to cartilage frequently result in the formation of what type of cartilage in the perichondrium?
Repair cartilage
[undifferentiated cells will differentiate into chondrocytes that synthesize components of the cartilage matrix]
Repair cartilage facilitates the healing of what major type of injury?
Bone fracture
Repair catilage has a matrix composition intermediate between hyaline and fibrous cartilage. What types of collagen does it contain?
Types I and II
T/F: cartilage repair is age dependent, and it can be replaced by dense CT or bone
True
What is the relationship between stability and mobility in joints?
Inverse relationship, as stability increases mobility will decrease and vice versa
What are the 3 major types of joints classified by movement?
Synarthrosis - little or no movement
Amphiarthrosis - slightly mobile
Diarthrosis - freely mobile
What component of synovial joints is an outer fibrous layer made of dense regular CT and functions to strengthen the joint?
Articular capsule
What is the difference between extrinsic vs. intrinsic ligaments associated with synovial joints?
Extrinsic = separate from capsule
Intrinsic = part of fibrous capsule
Articular cartilage of synovial joints is made up of hyaline cartilage (note: without perichondrium), and serves to reduce friction. Since it is avascular, what provides nutrition to the articular cartilage?
Synovial fluid
The synovial membrane lines the synovial joint cavity, except for which location?
The articular cartilage
What are the 2 types of synoviocytes?
Type A macrophage-like synovial cells
Type B fibroblast-like synovial cells
What percentage of cells lining the synovium are type A macrophage-like synovial cells?
25%
What are the major functions of type A macrophage-like synovial cells?
Phagocytic, contain lysosomes to clear articular cavity of debris formed by friction of articular cartilages, regulate inflammatory events
What are the major functions of type B fibroblast-like synovial cells?
Produce synovial fluid (plasma filtrate)
Produce hyaluronate that combines with synovial fluid
Lubricates/nourishes the articular cartilage
In articular cartilage of synovial joints, collagen fibers run ____________ to the tissue surface and bend gradually to form an arc
Perpendicular
What are the 4 layers of articular cartilage from superficial to deep?
Tangential layer
Transitional layer
Radial layer
Calcified layer
Which of the following layers of articular cartilage is described below:
Chondrocytes slightly larger and round, occurs both alone and in isogenous groups, collagen fibers take an oblique course through the matrix
A. Tangential
B. Transitional
C. Radial
D. Calcified
B. Transitional
Which of the following layers of articular cartilage is described below:
Chondrocytes are small and flattented parallel to the surface, most superficial region is devoid of cells, collagen fibers run parallel to the surface
A. Tangential
B. Transitional
C. Radial
D. Calcified
A. Tangential
Which of the following layers of articular cartilage is described below:
Large chondrocytes form radial columns, stacks are oriented perpendicular to the articulating surface, collagen fibers follow orientation of chondrocyte columns
A. Tangential
B. Transitional
C. Radial
D. Calcified
C. Radial
Which of the following layers of articular cartilage is described below:
Rests on underlying cortex of bone, matrix stains darker than other layers
A. Tangential
B. Transitional
C. Radial
D. Calcified
D. Calcified
What are some of the signs and symptoms of osteoarthritis?
Pain Tenderness Limited ROM Swelling Joint deformity
