9/14 Cartilage Histology - Dennis (Completed) Flashcards
What is the function of cartilage? 3
Specialized CT
Provides flexible, semi-ridged, resilient support
Shock absorber & fracture repair
What are the three types of cartilage? What collagen is predominant in each? 3
Hyaline - type II collagen
Fibrocartilage - Type I collagen
Elastic - type II collagen
What cells are contained within cartilage? What are their functions? 5
Chondroblasts –> secrete cartilage matrix
Chondrocytes –> matured chondroblasts trapped in the lacunae, maintain the matrix
What is the ground substance of cartilage? 5
Proteoglycans:
Hyaluronic acid
Chondroitin sulfate
Keratin sulfate
Aggrecan
Where would you find hyaline cartilage? 6
Nasal septum
Larynx/trachea/bronchi
Embryonic development
Ribs
Where would you find elastic cartilage? 6
External ear epiglottis
Auditory tube
Where would you find fibrocartilage? 6
Intervertebral discs
Pubic Symphysis
TMJ
What cartilage subset lacks a perichondrium? 7
Articular cartilages (a type of hyaline cartilage)
What is found in the territorial matrix? 9
Type II collagen w/ random arrangement, small concentration
High GAGs
Immediately surrounds cells
What is found in the interterritorial matrix of cartilage?
Higher concentration of collagen II
Fewer GAGs
What kind of tissue makes up perichondrium? 10
Dense Regular CT w/ vasculature
What are the two components of the perichondrium? 10
Outer fibrous layer
Inner chondrogenic layer
What layer makes up the transitional zone between cartilage and surrounding CT? 10
Outer Fibrous Layer
What does the outer Fibrous layer of the perichondrium produce? 10
Type I collagen
Elastin
What does the Inner Chondrogenic Layer of the perichondrium produce? 10
type II collagen
Chondroblasts
How are chondrocytes oriented within fibrocartilage? 12
In columns oriented in the direction of functional stress
Which of the three types of cartilage lacks a perichondrium? 12
Fibrocartilage
Differentiate Interstitial vs appositional growth? 13
Interstitial growth –> increase length of cartilage (takes place within cartilage mass)
Appositional growth –> produces chondroblasts (takes place on surface of cartilage mass right under perichondrium)
What occurs during cartilage repair? 15
Repair can be initiated from the perichondrium
Undifferentiated cells differentiate into chondrocytes –> synthesizes cartilage matrix
Repair cartilage has both type I and II collagen (w/ age replaced by dense CT)
What are Synoviocytes? 20
Type A (macrophage-like)
Type B (fibroblast-like)
What is the role of Type A Synoviocytes? 20
Macrophage-like
Regulate inflammation, phagocytizes, cleans with lysosomes
25%
What is the role of Type B synoviocytes? 20
Fibroblast-like
Produces synovial fluid and hyaluronate
Lubricrates and nourishes the articular cartilage
What are the layers of articular cartilage? 21
Tangential layer –> small chondrocytes, devoid of cells
Transitional layer (biggest)
Radial layer –> chondrocytes organized into columns
Calcified cartilage –> interfaces with bone
How are cells arranged within Hyaline, Elastic, and Fibrocartilage? 6
Hyaline Cartilage –> chondrocytes surrounded by territorial and interteritorial matrix
Elastic Cartilage –> chondrocytes surrounded by territorial and interteritorial matrix
Fibrocartilage –> chondrocytes alighted along stress lines
