What is the main function of cartilage?
Mechanical support for softer tissue and a joiner of hard tissue
Cushions shock
What type of tissue models the shape of the face?
Cartillage
What type of cells make cartillage?
Chondroblasts
How are cells arranged in mature cartilage tissue?
Chondrocytes sit in holes (lacunae) of cartilage
True or false? There are blood vessels invaginating the cartilage matrix?
False, there are NO blood vessels in the cartilage matrix
What mostly comprises the cytoplasm of chondrocytes?
Glycogen droplets
How do chondrocytes dispose of wastes?
Diffusion
What happens if oxygen builds up in cartilage tissue?
Chondrocytes die
What type of cell is most likely to be found at the edge of developing cartilage extracellular matrix?
Chondroblasts
What are the three main cartilage types?
- Hyaline cartilage
- Elastic cartilage
- Fibrocartilage
What type of protein(s) primarily compose hyaline cartilage?
Type II collagen with proteoglycans
What type of protein fibre primarily composes elastic cartilage?
Elastin
What is the general structure of hyaline cartilage?
Protein collagen fibril backbones run through it, glycans form side chains that are rich in water and form a gel
What is the connective tissue layer around cartilage matrix called?
The perichondrium
What type of connective tissue forms the perichondrium of cartilage matrix? What type of collagen is prevalent?
Dense irregular with type I collagen fibres
What is the function of perichondrium to cartilage tissue?
Attaches cartilage to whatever substrate is nearby
What type of cartilage surrounds the trachea?
Hyaline cartilage, strong enough to keep it open all the time
What type of cartilage is found at joints?
Articular cartilage
- A type of hyaline cartilage that doesn’t have a perichondrium
What type of tissues comprise the epiglottis?
Elastic cartilage covered by epithelium
What type of cartilage comprises the nose and ears?
Elastic cartilage
Where is fibrocartilage found?
In places that deal with a heavy load, such as knee joints, vertebrae and pubic bone.
What is the ground substance of cartilage composed of? (2)
- Macromolecules
- Fibres
How are collagen fibres arranged in articular hyaline cartilage of the joints?
Near the articular surface collagen fibres run parallel to the surface. Near the bone (where calcified cartilage can be found), the cartilage runs perpendicular to the surface.
What determines the physical properties of cartilage?
Electrostatic bonds between the flexible collagen and elastin fibers and the GAGs on densely packed proteoglycans.
Out of the three main types of cartilage, which is mostly likely to be found in body regions subject to pulling forces?
Fibrocartilage, (eg. cartilage of intervertebral disks)
What is analogous of the perichondrium in articular cartilage?
The perichondrium is dense connective tissue that normally surrounds cartilage and provides nutrients be diffusion. Articular cartilage in joints don’t have a perichondrium, but they do have synovial fluid, which can circulate and provide nutrients by diffusion.
Where is hylanine cartilage found in the body?
- The articular surfaces of moveable joints
- Walls of the respiratory passages
- Ventral ends of rib, articulating with the sternum
- Epiphyseal plates of long bones, for longitudinal bone growth
What type of cartilage forms the temporary skeletons of embryos that are replaced by bone?
Hylanine cartilage
What is the most abundant proteoglycan in hyaline cartilage?
Aggrecan
What does aggrecan do in hyaline cartilage ECM?
As the most abundant proteoglycan, it binds together type II collagen fibrils. It is attached to a hyaluronic acid core that runs between two collagen fibrils
List some areas of the body where you will find elastic cartilage
- auricle of the ear
- walls of external auditory canal
- Epiglottis
- cruneiform cartilage in the larynx
Elastic cartilage in thesse locations includes a perichondrium similar to that of most hyaline cartilage (articular cartilage being the exception)
Which type of cartilage is basically a combination of hyaline cartilage and dense connective tissue?
Fibrocartilage
Does fibrocartillage contain a distinct perichondrium?
No, hyaline-like cartilage and dense connective tissue blend into each other with no clear border.
What do chondroblasts look like in developing cartilage tissue?
A group of many chondroblasts together. As they secrete ECM they will isolate themselves and become chondrocytes
What two types of growth are observed in cartilage tissue?
- Interstitial growth, from dividing chondroblasts
- Appositional growth, differentiation of new chondroblasts from the perichondrium