Histology - Musculoskeletal Block (II) Flashcards
What are the three main types of cartilage?
Hyaline;
elastic;
fibrous
What type of fibers are most prevalent in hyaline cartilage?
What type of fibers are most prevalent in elastic cartilage?
What type of fibers are most prevalent in fibrocartilage?
Type II collagen;
elastic fibers and type II collagen;
types I and II collagen
What type of fibers are most prevalent in hyaline cartilage?
Type II collagen
What type of fibers are most prevalent in elastic cartilage?
Elastic fibers; type II collagen
What type(s) of fibers are most prevalent in fibrocartilage?
Types I and II collagen
What are some examples of hyaline cartilage in the body?
Costal cartilage;
articular cartilage;
tracheal rings
What are some examples of elastic cartilage in the body?
Ears,
epiglottis,
part of the larynx,
auditory tubes
What are some examples of fibrocartilage in the body?
Intervertebral discs;
pubic symphysis;
menisci of the knee joint
What type of cell is most prevalent in hyaline cartilage?
What type of cell is most prevalent in elastic cartilage?
What type of cell is most prevalent in fibrocartilage?
Chondrocytes;
chondrocytes;
fibroblasts
What percentage of cartilage is typically made up by ground substance?
90 - 95%
Chondrocytes receive their nutrients via:
Diffusion
(cartilage is an avascular tissue)
The functional component of cartilage is:
the ECM
What type of cartilage is in the ear?
What type of cartilage are the menisci of the knee?
What type of cartilage is the epiglottis?
What type of cartilage are the intervertebral discs?
Elastic;
fibrocartilage;
elastic;
fibrocartilage
What two types of cartilage are found in the knee?
Articular (lining the joint);
fibrocartilage (the menisci)
Chondrocytes sit in hollow spaces within the ground substance called:
Lacunae
Is ground substance eosinophilic or basophilic?
Basophilic (blue or dark purple)
What are the three layers of ECM in the cartilage surrounding chondroblasts?
(How strongly does each stain?)
What type of fiber predominates here?
The pericellular matrix (visible with special staining);
the territorial matrix (lightly stained);
the interterritorial (interstitial) matrix (heavily stained);
type II collagen
What two stains are used for elastic fibers?
Verhoeff’s;
orcein
What are the two types of cartilaginous growth?
Appositional (from the perichondrium);
interstitial (within the tissue by existing chondrocytes)
How many chondrocytes are typically found in each lacunae?
1 - 2
If there are two or more chondrocytes in one lacunae, these chondrocytes are termed:
Isogenous groups
What are the three types of cartilage?
Hyaline,
elastic,
fibrocartilage
Which types of cartilage have a surrounding perichondial layer?
Hyaline (excepting articular cartilage);
elastic
Describe the layers of hyaline cartilage from superficial to deep.
Fibrous layer (perichondrium)
Chondrogenic layer (perichondrium)
Inner chondrogenic layer (chondroblast differentiation)
Mature cartilage
The outer (fibrous) layer of cartilaginous perichondrium found in hyaline cartilage is what type of tissue?
Dense irregular connective tissue (type I collagen)
What is the major proteoglycan of hyaline cartilage?
What is the major glycoprotein of hyaline cartilage?
Aggrecan;
chondronectin
What substance forms the fetal skeleton?
How does it form bone?
Hyaline cartilage;
endochondrial ossification
Which type of cartilage has no perichondrial layer?
Fibrocartilage
What type of cartilage is shown here?
Elastic cartilage
What is shown in this transmission electron micrograph?
Two chondrocytes within in a lacunae
(blue line = lacunae;
RER very abundant)
What is the predominant type of collagen is found in fibrocartilage?
What is the predominant type of collagen is found in hyaline cartilage?
What is the predominant type of collagen is found in elastic cartilage?
Type I (some type II present);
type II;
type II (elastic fibers also present)
What type of cartilage does NOT calcify with age?
Elastic cartilage
What type of tissue is this?
Elastic cartilage
What type of tissue is this?
Fibrocartilage
(note the lack of distinct layers and presence of interspersed type I collagen with ground substance)
What is unique about the orientation of the chondrocytes in fibrocartilage?
They usually occur in rows
(see attached image)
Fibrocartilage is resistant to what two types of force?
Compressive;
shear
What type of tissue is this?
Fibrocartilage
Damaged perichondrium will likely have what response?
Fibroblast proliferation / scar formation
What type of tissue is this?
Fibrocartilage
What type of cartilage has no perichondrium?
Fibrocartilage
Fibrocartilage
Hyaline cartilage;
isogenous groups
A - fibrous perichondrium
B - chondrogenic perichondrium
Arrows - isogenous groups
Name the three types of cartilage and the predominant connective tissue fibers found in each.
Hyaline cartilage - collagen type II
Elastic cartilage - collagen type II and elastic fibers
Fibrocartilage - collagen type I and II
Describe the general makeup of hyaline cartilage ground substance.
Glycosaminoglycans (GAGs) attached to proteoglycan core proteins that are linked together by long chains of hyaluronic acid
Is cartilage basophilic or eosinophilic?
Why?
High prevalence of sulfate and carboxyl groups in glycosaminoglycans (GAGs)
What is the precursor cell for chondroblasts?
Mesenchymal cells
Which ECM is closest to chondrocytes and enriched in glycosaminoglycans (GAGs)?
Territorial matrix
What part of cartilage is basophilic?
What part of cartilage is eosinophilic?
Glycosaminoglycans (sulfate and carboxy groups, in particular);
collagen fibers
Which is more basophilic, the interterritorial (interstitial) matrix or the territorial (pericellular) matrix?
Why?
Territorial
(higher ratio of glycosaminoglycans to collagen fibers)
What type of strength does hyaline cartilage have due to its meshwork of type II collagen?
Tensile strength
Why is it important that ground substance is so good at storing water?
It enables diffusion of nutrients through hydrated matrix to chondrocytes
What type of cartilaginous growth involves new chondroblasts differentiating from the inner chondrogenic perichondrial layer?
Appositional growth
(as opposed to interstitial)
What type of cartilaginous growth involves mature chondrocyte replication within lacunae?
Interstitial growth
(as opposed to appositional)
What is a damaging effect of cartilage calcification?
Decreased nutrient diffusion
(and resulting chondrocyte apoptosis)
What natural process can limit diffusion of nutrients through cartilage and result in chondrocyte apoptosis?
Calcification
What type of cartilage is the cartilage of the nose?
Describe the pieces of cartilage present in the nose.
Hyaline
What type of tissue is the precursor of bone at the endochondral plates?
Hyaline cartilage
Does articular cartilage have a perichondrium?
No;
although other hyaline cartilage does
Articular cartilage replicates via what type(s) of growth?
Interstitial only
(no perichondrium = no appositional growth)
Why does articular cartilage not rapidly regenerate in cases of osteoarthritis?
Articular cartilage has no perichondrium and relies on the very limited interstitial growth to regenerate
Verhoeff stain is especially useful in visualising what type of fiber?
Elastic
Orcein stain is especially useful in visualising what type of fiber?
Elastic
What is the main feature of elastic cartilage as compared to the other types?
It’s flexibility and ability to return to its original shape
What type of cartilage is the most eosinophilic?
Why?
Fibrocartilage;
higher ratio of collagen fibers to ground substance
What is the strongest of the three types of cartilage?
Fibrocartilage
What type of cartilage is often found on portions of tendons or ligaments that insert into cartilage?
Fibrocartilage
What are the two macroscopic types of mature bone?
Compact (dense);
cancellous (spongy; trabecular)
What lines the outside of bones?
What type of tissue is it?
Periosteum;
dense irregular connective tissue
What are the three main regions seen in a long bone?
Epiphysis (ends)
Metaphysis
Diaphysis (shaft)
Metaphysis
Epiphysis (ends)
What are the two microscopic types of mature bone?
Mature (Lamellar; compact);
primary (woven)
What are the two macroscopic types of mature bone?
What are the two microscopic types of bone?
Do the two macroscopic types correspond to the two microscopic types?
Compact (dense), cancellous (spongy, trabecular);
mature (compact, lamellar), primary (woven);
Sort of.
Both type of macroscopic structure refer to mature bone (both compact or cancellous would be considered lamellar, although compact in the microscopic sense tends to correspond with compact in the macroscopic sense)
What is woven bone?
A microscopic type of immature bone consisting of irregularly aligned collagen fibers
True/False.
Spongy bone can also be lamellar as a cross-section of one of the trabecula will show lamellar arrangement.
True.
What is the functional unit of compact bone?
The osteon (Haversian system)
What are the microscopic layers of a long bone from superficial to deep?
Periosteum (DICT);
external circumferential lamellae;
osteons (Haversian systems) + interstitial lamellae);
internal circumferential lamellae;
trabeculae
What are the three types of lamellae encasing osteons in long bone?
External circumferential lamellae;
interstitial lamellae;
internal circumferential lamellae;
What lumen runs down Haversian systems (osteons)?
What tube connects these lumens?
Haversian (central) canals;
Volkmann’s (perforating) canals