Lecture 13 Bone and Cartilage Flashcards
True of False:
The skeletal system in all vertebrates begins as cartilage.
True, the skeletal system in all vertebrates does begin as cartilage.
What are the two different cell types that make up cartilage?
1) Chondroblasts (cartilage-forming cells)
2) chondrocytes (cartilage-maintenance cells)
What are the 3 major types of cartilage?
1) Hyaline Cartilage
2) Elastic Cartilage
3) Fibrocartilage
What two components make up the extracellular matrix in cartilage?
1) Collage fibers
* mostly type II collagen (type I in fibrocartilage)
2) Amorphous ground substance
Name a few of the 6 functions that cartilage has?
1) Compressible
2) Resists Distortion
3) Absorbs shock in joints
4) Reduces friction in movable joints
5) Necessary for endochondral bone growth
6) Involved in bone fracture repair
What do chondrocytes do?
Chondrocytes maintain the cartilage matrix.
What is the primary function of chondroblasts?
Chondroblasts lay down cartilage matrix and become chondrocytes.
What is a lacunae, and which two cell types would you find there?
A lacunae is a pocket within the cartilage matrix where the chondrocytes and chondroblasts are found.
*Lacunae means “little lake”
Since cartilage is avascular, how does cartilage get nutrients and oxygen?
Nutrients and oxygen are derived from blood vessels that surround the cartilage and must diffuse through the matrix to the cells.
A patient presents to you in the clinic 2 months after a cartilage tear and is upset with the slow recovery and assure you they have attended all of their physical therapy sessions. What characteristic of cartilage would you tell them about to explain the slow recovery?
That cartilage is avascular, thus, slow recovery is expected. You could also include how cartilage gets it nutrients into the matrix from blood vessels.
What are the two layers that make up the perichondrium?
*Outer fibrous layer:
>contains fibroblasts
*Inner chondrogenic layer:
>gives rise to chondroblasts, which become chondrocytes
>the condrocytes is involved in the production of the collagen and proteoglycans in the matrix. Chondrocytes also secrete chondronectin.
What makes up an isogenous group? What is the isogenous groups a result from?
- groups of 2-8 chondrocytes occupying the same lacunae
- result of mitotic division
- cells will become separated as they begin to lay down matrix of their own.
Which matrix (territorial or inter-territorial) surrounds each condrocyte?
Territorial matrix
True or False:
The inter-territorial matrix surrounds the territorial matrix.
True
Fill in the Blank:
_____matrix has a high glycoaminoglycan content and a low collagen content.
Territorial Matrix
Fill in the Blank:
_____matrix has a low glycoaminoglycan content and a high collagen content.
Inter-territorial matrix
What 3 sulfate containing compounds are components of the cartilage matrix?
Chondroitin Sulfate
Keraten Sulfate
Heparin Sulfate
True of False:
Glycosaminoglycans are not a component of the cartilage matrix.
False, glycosaminoglycans are a component of the cartilage matrix.
Which sulfer-less containing component is found in the cartilage matrix?
Hyaluronan (hyaluronic acid)
What is the most abundant form of collagen found in the cartilage matrix? What about in fibrocatilage, is it the same type of collagen?
Collagen type II is the most abundant, except for in fibrocartilage, which is made up of predominately type I collagen.
What is the most common type of cartilage found in the body and what type of collagen fibers does it contain?
Hyaline Cartilage and Type II Collagen
What are the two growth patterns that hyaline cartilage undergoes?
Appositional
Interstitial
Give examples of where hyaline cartilage is found within the body.
External Auditory Meatus
Larynx
Tracheal Cartilages
Bronchial Cartilages
Fetal Long Bones
Articular Ends of Bones
Chondroitin sulfate, type I collagen fibers, and proteoglycans are the 3 most abundant components found in the matrix of hyaline cartilage?
True
What are the two types of perichondrium found in hyaline cartilage?
Fibrous Perichondrium (source of fibroblasts)
Chondrogenic Perichondrium (source of chondroblasts and osteoprogenitor cells)
Give some examples of where elastic cartilage would be found.
Auricle (pinna) of the ear
Epiglottis
Which 2 major cartilage types are surrounded by a perichondrium and which one is not?
Hyaline and Elastic cartilage are surrounded by a perichondrium.
Fibrocartilage is not surrounded by a perichondrium.
What gives elastic cartilage its yellow color?
The elastic fibers
Where is fibrocartilage typically found?
- intervertebral discs
- pubic symphysis
- insertion of some tendons and ligaments
- closely associated with dense connective tissue or hyaline cartilage
What are the small cavities called in the extracellular matrix that chondrocytes occupy?
Lacunae
True or False:
Interstitial growth of cartilage is very active during endochondral ossification.
True
What are the 3 classifications of bone that are determined by matrix arrangement?
- Woven Bone
>occurs during bone development and bone repair - Compact Bone
>also called lamellar bone
*Spongy Bone
>also called trabecular or cancellous bone
Which 2 major components make up the matrix of bone?
- An organic component referred to as osteoid.
2. An inorganic component referred to as hydroxyapatite which makes up 35 to 65 percent of the matrix.