Cartilage Flashcards
What constitute the supportive CT? and what is the function?
Function: support soft tissues and body weight. 1. cartilage (shock absorption and protection) 2. Bone (weight support)
What is the cartilage matrix composed of?
- proteoglycans (derived from chondroitin sulfate) 2. ground substance proteins
What are chondrocytes and what do they produce?
they are cartilage cells and produce antiangiogenesis factor.
What are the two layers of the perichondrium?
- outer –> fibrous (strength) 2. inner–> cellular (growth and maintenance)
What is the fetal skeleton composed of?
hyaline cartilage.
What type of collagen fiber will you find in the matrix?
Type II
what type of CT is cartilage?
dense CT
From where do additional chondrocytes arise?
fibroblast-like-stem cells in the perichondrium
What substance do chondrocytes secrete?
type II collagen fiber and ground substance
Where is collagen synthesized
RER
What constitute the ground substance?
GAGs Proteoglycans proteoglycans aggregates glycoproteins tissue fluid
What are GAGs composed of?
chondroitin sulfate and hyaluronan.
What is a lacuna?
potential space occupied by a chondrocyte. This is only visible after cell’s death or ager shrinkage during tissue processing.
What is the difference between capsular(territorial) an intracapsular (inter territorial) matrix?
The capsular (territorial) matrix is the matrix immediately surrounding the chondrocyte. This is more basophilic (acidic) and PAS-positive than inter capsular matrix (higher sulfated GAG concentration and lower collagen concentration. )
Where is cartilage derived from?
embryonic messenchyme.
What is mesenchymal condensation?
this is a process that happens when mesenchymal cells retract their cytoplasmic extensions and become round shape, becoming more tightly packed. This stimulated the commitment to cartilage differentiation.
When does a chondroblast becomes a chondrocyte?
when is surrounded by cartilage matrix
What are the two process of cartilage growth? and what do they involve?
They both involve mitosis and deposition of additional matrix. 1. Interstitial growth: division of existing chondrocytes and gives rise to isogenous groups. Division within the lacuna. As the daughter cells secret matrix they move apart. **Important in fetal skeleton and continues in the epiphyseal plates and articular cartilages 2. Appositional growth: involves differentiation of chondrocytes by chondroblast and stem cells on perichondrium inner surface. **It is responsible for increases in the growth of the cartilage masses.
Matrix synthesis is affected by what factors?
enhanced by growth hormones, thyroxine, and testosterone. inhibited by estradiol and excess cortisone.
What is the function and location of hyaline cartilage?
Function: Reduces friction in joints. Its ability to grow rapidly while maintaining its rigidity makes hyaline cartilage an ideal fetal skeletal tissue. Location: The costal (rib) cartilages, most of the laryngeal cartilages, the cartilaginous rings supporting the trachea, and the irregular cartilage plates in the walls of the bronchi are hyaline cartilage.
How is elastic carriage different from elastic cartilage?
it contains collagen II and elastic fibers.
how does elastic cartilage looks?
It has perichondrium, chondrocytes occur in isogenous groups and is stained darker than hyaline cartilage.
Where does elastic fibers develop from?
Elastic cartilage develops from a primitive connective tissue containing wavy fibrillin bundles. Fibroblasts subsequently secrete elastin, and the fibrillin bundles are transformed into branching elastic fibers.
Where is elastic cartilage located?
elastic cartilage occurs in the external ear, the external auditory canals and auditory tubes, the epiglottis, and the corniculate and cuneiform cartilages of the larynx.
What type of fibers collagen fibers occur in fibrocartilage?
collagen type I. Always associated with dense CT.
Where is fibrocartilage located?
where strong mechanical stresses occur. intervertebral disks, the symphysis pubis, and some bone–ligament junctions.
