cartilage histology

Question 1

What are some characteristics of cartilage?

Answer 1

Semi-rigid tissue comprised of cells and ECM- no nerve/lymphatics/vascular supply- ECM contains collagen and elastic fibers that are crucial for survival of chondrocytes

Question 2

What are the components of cartilage?

Answer 2

Chondroblast, chondrocytes and matrix

Question 3

What are chondroblast?

Answer 3

The are cells that secrete cartilage matrix and have mitotic capabilities

Question 4

What are chondrocytes?

Answer 4

mature cartilage cells in the lacunae surrounded by and maintain matrix

Question 5

What is the composition of the matrix?

Answer 5

Type 2 collagen is most predominant for the fibers, there are elastin fibers
the ground substance is proteoglycans

Question 6

What are the three types on cartilage?

Answer 6

hyaline, elastic and fibrocartilage

Question 7

Where is hyaline cartilage found?

Answer 7

articular cartilage, larynx, trachea, ribs and embryonic development

Question 8

Where is elastic cartilage found?

Answer 8

external ear, epiglottis and auditory tube

Question 9

Where is fibrocartilage found?

Answer 9

intervertebral disk, pubic symphysis and TMJ

Question 10

What are the similarities between elastic and hyaline cartilage?

Answer 10

They both are comprised of mostly type 2 collagen and are surrounded by perichondrium

Question 11

What makes fibrocartilage unique?

Answer 11

It is comprised mostly of type 1 cartilage and has no perichondrium

Question 12

What are isogenous groups and what type of cartilage is it found in>

Answer 12

They are groupings of chondrocytes that are surrounded by matrix found in hyaline cartilage

Question 13

What is the territorial matrix?

Answer 13

Stains darker than interterritorial matrix- consist of type 2 collagen randomly arranged- has more GAGs than collagen

Question 14

What is interterritorial matrix?

Answer 14

Stains lighter than territorial matrix- has more collagen than proteoglycans

Question 15

What is perichondrium?

Answer 15

Dense irregular CT- has vascular supply- contains the new cartilage cells- divided into two layers

Question 16

What are the two layers of perichondrium?

Answer 16

The fibrous layer and the chondrogenic layer

Question 17

What is the fibrous layer of the perichondrium?

Answer 17

the outer layer that produces type 1 collagen and elastin - this is the transitional zone between cartilage and general CT

Question 18

What is the chondrogenic layer of the perichondrium?

Answer 18

The inner layer that differentiates into chondroblasts- produces the type 2 collagen

Question 19

What is elastic cartilage?

Answer 19

Contains components of hyaline cartilage and elastic fibers in its matrix. surrounded by perichondrium

Question 20

What is fibrocartilage?

Answer 20

This is a combination of hyaline cartilage and dense regular CT- there is type 1/2 collagen with less matrix and no perichondrium

Question 21

How does the structure of fibrocartilage assist in its function?

Answer 21

matrix and isogenous groups aligned in rows that allow it to withstand compression and shearing forces

Question 22

What are the two types of chondrogenesis?

Answer 22

Appositional growth and interstitial growth

Question 23

What is appositional growth in chondrogenesis?

Answer 23

forms new cartilage on the surface of old cartilage- cells located in the chondrogenic layer of perichondrium- grow from undifferentiated cells

Question 24

What is interstitial growth in chondrogenesis?

Answer 24

takes place within the cartilage mass- Chondrocytes divide within the lacunae, creating new isogenous groups- limited due to avascular nature

Question 25

What is the articular capsule?

Answer 25

there is an outer fibrous layer made of dense regular CT and extrinsic and intrinsic ligaments

Question 26

What is the synovial membrane?

Answer 26

lubricates articular capsule with synovium- vascular CT membrane, has regenerative properties and absorbs shock

Question 27

What is the articular cartilage?

Answer 27

composed of hyaline cartilage, reduced friction, avascular and no nerve supply, nourished by synovial fluid

Question 28

What are synoviocytes?

Answer 28

There are two types, A and B- they are cells present in the synovial fluid

Question 29

What is a type A synoviocyte?

Answer 29

A macrophage like cell that does phagocytosis, has lysosome to clear articular cavity of debris from friction, regulate inflammatory process

Question 30

What is a type b synoviocyte?

Answer 30

A fibroblast like cell that will produce synovial fluid, also produce hyaluronate that will mix with synovial fluid- lubricates articular cartilage

Question 31

What is the general structure of articular cartilage?

Answer 31

collagen fibers that run perpendicular to the tissue surface and bend gradually to form an arch- there is distinct layering

Question 32

What are the 4 layers of articular cartilage?

Answer 32

superficial (tangenital zone) Intermediate (transitional) zone Deep (radial) zone Calcified zone

Question 33

what is the superficial zone of articular cartilage?

Answer 33

the chondrocytes are small and flattened to be parallel with the surface- most superficial and the fibers run parallel to surface

Question 34

What is the intermediate zone of articular cartilage?

Answer 34

Chondrocytes are slightly larger and round- occurs alone and in isogenous groups, collagen begins to become more oblique

Question 35

What is the deep zone of articular cartilage?

Answer 35

Large chondrocytes that form radial columns, stacks are perpendicular to surface, collagen is perpendicular as well

Question 36

What is the calcified zone of the articular cartilage?

Answer 36

Rests on the underlying cartilage and will stain slightly darker on stains