Lecture 13 Bone and Cartilage Flashcards
What are the three major classes of cartilage?
Hyaline Cartilage Elastic Cartilage Fibrocartilage
The three major classes of cartilage are based on what characteristics?
Their matrix, especially the types of fibers
What are the two types of cartilage cells?
Chondroblasts Chondrocytes
What makes up the extracellular matrix of cartilage?
Collagen fibers (usually type II; Type I in fibrocartilage) Amorphous ground substance
Name the functions of Cartilage (6)
Compressible Resists distortion Absorbs shock in joints Reduces friction in movable joints Necessary for endochondral bone growth Involved in bone fracture repair
What is the function of a chondroblast?
Lay down cartilage matrix and become chondrocytes
What is the function of a chondrocyte?
Maintain cartilage matrix
What are Lacunae?
Pockets within the matrix where the chondroblasts and chondrocytes are found
Is cartilage vascular or avascular?
Avascular - Slow to heal - Nutrients and oxygen derived from BV’s that surround cartilage
What are the layers of the Perichondrium?
Outer fibrous layer Inner chondrogenic layer
What makes up the outer fibrous layer of the perichondrium?
Fibroblasts
What makes up the inner chondrogenic layer?
Gives rise to chondroblasts, which become chondrocytes Chondrocyte is involved in production of collagen and proteoglycans in the matrix. Also secrete chondronectin
What is an isogenous group and what is it the result of?
Group of 2-8 chondrocytes occupying the same lacunae Result of mitotic division
What are the components of the cartilage matrix?
Collagen type II (type I in fibrocartilage) Hyaluronan (hyaluronic acid) Chondroitin sulfate, keratan sulfate, Heparin sulfate GAGs
What is the name of the matrix that surrounds each chondrocyte and what is its content?
Territorial matrix High GAG content; low collagen content
What is the tame of the matrix that surrounds the territorial matrix and what is its content?
Inter-territorial matrix Low GAG content; high collagen content
Name the characteristics of Hyaline Cartilage
Most common type Avascular Type II collagen Surrounded by perichondrium Translucent, bluish gray to white Solid but flexible Chondrocytes ofter found in cell groups Both appositional and interstitial growth
Name locations of hyaline cartilage
External auditory meatus Larynx Tracheal Cartilages Bronchial Cartilages Fetal Long Bones Articular Ends of Bones
Identify the Following
A: Fibrous perichondrium
B: Chondrogenic perichondrium
C: Lacuna
D: Chondrocytes
E: Matrix
Name the Characteristcs of Elastic Cartilage
Specialized by the addition of elastic fibers to the matrix
Surrounded by perichondrium
Yellow color b/c of elastic fibers
More Opaque, Flexible, and Elastic than Hyaline
Chondrocytes mostly located singly
Type II collagen plus elastic
Where can Elastic Cartilage be found?
Auricle (pinna) of the ear
Epiglottis
Name the Characteristics of Fibrocartilage
Increased collagen in the matrix
Reduced cellularity compared to hyaline
Not surrounded by perichondrium
Opaque appearance from fibrous texture
Type I collagen
Single sparse chondrocytes
Where can Fibrocartilage be found?
Intervertebral discs
Pubic symphysis
Insertion of some tendons and ligaments
Closely associated with dense CT or hyaline
Identify the Image
Hyaline Cartilage
