Histology Lecture 5 - Cartilage and Bone Flashcards
(27 cards)
What is the diaphysis of a bone?
The long shaft
Where are epiphyses found?
At the ends of long bones
What type of cartilage covers articular surfaces?
Hyaline
What type of cartilage is found in the nose and respiratory tree?
Hyaline
What comprises hyaline cartilage?
Type II collagen and chondroitin sulfate proteoglycans (aggrecan shit).
Where is collagen type IX found?
Found in hyaline cartilage, it coats the type II fibrils and is called “fibril-associated collagen”
What are lacunae?
Refers to a “hole,” can be found in cartilage and bone, and is where the cells hang out (chrondrocytes in cartilage, osteocytes in bone).
What is the perichondrium?
Dense irregular CT surrounding hyaline cartilage (except in articular surfaces) and elastic cartilage. Also does NOT surround fibrocartilage.
What is the only branching CT?
Elastin
Where are isogenic clusters found? What are they involved in?
These clusters of chondrocytes are found in hyaline cartilage and are involved in interstitial growth.
Where do osteons occur?
Compact bone only
What type of collagen do fibroblasts synthesize?
Type I
Where are perichondrial cells found? What can these cells do?
In the perichondrium (dense irregular CT surrounding hyaline cartilage). These cells look like fibroblasts and can differentiate into chondroblasts to build cartilage via appositional growth.
What does fibrocartilage look like under LM? Where is it found in the body?
Looks like a mix between dense CT and cartilage. Found in vertebral discs, attachments of certain ligaments, and symphysis pubis.
What differentiates elastic cartilage from hyaline? Where is elastic cartilage found in the body?
Silver stain must be used to show elastin fibers, or else cannot tell difference. Found in ear, epiglottis, eustachian tube.
What percentage of bone is organic? What is the majority of the organic substance made of?
30% by dry weight, and 95% of that is type I collagen
What is hydroxyapatite?
The crystalline calcium-phosphate that impregnates collagen fibers of bone.
What is found in spongy bone?
Red marrow, blood vessels.
What is woven bone diagnostic of?
It indicates that the bone is in the growth stage. Has a high osteocyte/matrix ratio.
What are lamellae? What are the types?
The “layers” in bone (like tree rings). Types are outer and inner circumferential, Haversian, and interstitial.
What are Volkmann canals?
Vascular connections between Haversian canals.
What are canniculi?
The holes that allow for gap junctions in bone between osteocytes.
What is the periosteum? What connects it to the bone?
Sheath that surrounds the bone. Sharpey fibers hold it to the bone.
What is the endosteum?
Sheath that lines the medullary cavity of bone.
