Cartilage Histology Flashcards
What are the primary functions/characteristics of cartilage?
Semi rigid ( Cells and ECM w/ collagen and elastic fibers)
No nerve supply or lymphatics
Avascular
What are the three types of cartilage?
Hyaline
Elastic
Fibrocartilage
What are the characteristics of hyaline cartilage and where can it be found?
Characteristics: Type II collagen Has chondrocytes in isogenous groups Surrounded by perichondrium Location: Articular cartilage larynx trachea ribs embryonic development
What are the characteristics of elastic cartilage?
Where can it be found?
Characteristics:
Type II collagen
Surrounded by perichondrium
More restrictive in location than hyaline
Hyaline cartilage and elastic fibers located within the matrix
Location:
External ear
Epiglottis
Auditory Tube
What are the characteristics of fibrocartilage?
Where can it be found?
Characteristics: Combination of dense regular CT and hyaline Type I and II collagen Less cartilage matrix No perichondrium Chondrocytes aligned in isogenous groups Fibers oriented in direction of stress Withstand compression and shearing forces
Location:
Intervertebral discs
Pubic symphysis
TMJ
What divisions are cartilage matrix divided into? Describe their characteristics
Territorial:
Type II collagen
Closer to cells
Darker stained
Interterritorial:
Surrounds territorial matrix
Less intensely stained
Fewer proteoglycans
What makes up the perichondrium?
Where is it found?
Dense irregular CT
Which,
is Vascular
Surrounding hyaline and elastic cartilage
What are the two layers of the perichondrium? What is their overall function?
Fibrous and cartilaginous layers
They are the source of new cartilage cells
Where is the fibrous layer of the perichondrium located and what is its function?
Most outer layer
Makes Type I collagen and elastin
Transitional zone between cartilage and surrounding general CT
Where is the cartilaginous layer of the perichondrium located and what is its function?
Inner layer
Makes Type II collagen
Differentiates into chondroblasts
What are the two types of growth in hyaline cartilage?
Appositional growth and interstitial growth
Describe appositional growth of hyaline cartilage
Forms new cartilage on existing
Grows from undifferentiated chondrogenic cells of the perichondrium
Describe interstitial growth of hyaline cartilage
Takes place w/in cartilage mass
Limited by avascularity
Chondrocytes divide within lacunae, making new isogenous groups (overall size increases)
Describe cartilage repair.
Why is it limited in its ability to repair?
Repair cartilage forms via:
Matrix composition intermediate of fibrocartilage and hyaline cartilage
Type I and II collagen
Stimulates bone growth
Facilitates healing of bone fracture
Repair is age dependent and limited because of avascular nature
What is a joint?
Connects bone and bone
What are some characteristic parts of a synovial joint? (be able to identify on photo)
Articular capsule
Articular cartilage
Synovial membrane
Describe the synovial membrane
Lines joint cavity Lubricates articular cartilage Vascular CT membrane MAKES SYNOVIAL FLUOD Absorbs shock Regenerative properties
Describe the articular capsule
Outer fibrous layer w/ dense regular connective tissue Strengthens joint Extrinsic v. Intrinsic ligaments Extrinsic=separate from joint capsule Intrinsic= part of fibrous capsule
Describe articular cartilage
Lines surface of bone Hyaline cartilage Reduces friction NO VASCULATURE (Unlike the rest of hyaline cartilage) Synovial fluid provides nourishment
What are the two types of synoviocytes? Where are they located? What do they do?
Synovial membrane
Type A macrophage like synovial cells
Have lysosomes to clear articular cavity of debris formed from friction
Phagocytic
Regulate inflammatory events
Type B fibroblast like synovial cells
Produce synovial fluid
Produce hyalurinate that combines w/ synovial fluid
Lubricates and nourishes articular cartilage
Articular Cartilage layers
Superficial zone
Intermediate zone
Deep zone
Calcified zone
Osteoarthritis
What layers of articular cartilage are disrupted first?
What layers are disrupted during late stages?
Superficial
Extends to calcified bone; exposed subchondral bone becomes new articular surface
