L1 - Cartilage Flashcards
Where is cartilage found?
In articular joints of bones
In organs such as the trachea and bronchi
Costal cartilage connecting ribs to sternum
In the larynx
In the growth plate of long bones
In the nose, ears, epiglottis and Eustachian tubes
What are some properties of cartilage?
CT from mesenchymal stem cells Tough and resilient Contains 60-80% water No nerves or blood vessels Difficult to repair if damaged
Cartilage is covered with what?
Dense perichondrium which helps resist outer cartilage expansion when compressed
Contains stem cells
How do nutrients and gases travel through cartilage?
By diffusion
What are the main two cell types in cartilage?
Chondroblasts and chondrocytes
What are chondroblasts?
Forms initial cartilage (builds) and is located next to the perichondrium
Mitotic
Precursor to chondrocyte
What are chondrocytes?
Mature cells within spaces called lacunae
Separated from one another by ECM
Can proliferate to form clusters called isogenous groups
What is the amorphous component of cartilage?
ECM containing hyaluronic acid, proteoglycans and water
Which fibers are present in cartilage?
All have type II collagen but some have added elastin or type I collagen as well
What is perichondrium?
Layer of dense irregular CT covering hyaline and elastic cartilage
Essential for growth and maintenance of cartilage
Describe the outer/fibrous layer of perichondrium
Largely type I collagen and fibroblasts
Describe the inner/chondrogenic layer of perichondrium
Adjoins cartilage matrix
Contains mesenchymal stem cells serving as a source for new chondroblasts that will divide and differentiate into chondrocytes
What is the most abundant type of cartilage?
Hyaline cartilage
Describe characteristics of hyaline cartilage
ECM contains type II collagen fibrils, water, HA and proteoglycans (a very hydrated matrix)
Absorbs shock
Plays a key role in bone development and growth
Surrounded by a perichondrium
What is the surface appearance of hyaline cartilage?
Glassy, shiny and smooth