Cartilage Histology Lab

Cartilage Histology Lab

Cartilage is a connective tissue in which the cells are relatively sparse and embedded in a large amount of firm characteristic matrix. The matrix is composed of ground substance bound together with characteristic fibers which vary in composition and orientation according to the type of cartilage. Note the distinguishing characteristics in each of the following types of cartilage:

1. arrangement of cells
2. unusual details of the matrix
3. its staining characteristics
Identify the listed features, and illustrate a typical 400x field and, as always, give a brief description of the function and/or significance of each feature.


Hyaline cartilage
Hyaline cartilage

(slide 11) Hyaline cartilage
(VE: fig 3-3, p 41) (trachea):
Forms models for immature bones.
Forms epiphyseal cartilage on long bones by which they grow.
Gives shape to nose, trachea, etc.
Connects bones as with ribs to stermum.
Covers the mating surfaces of bones in sinovial joints.

It is resilient and shock absorbing.
Collagen is the primary fiber, chondroitin the major component of ground substance.

Here is a labeled view of hyaline cartilage and associated tissue.

Features to learn and label in your illustration

chondrocytes cells which maintain cartilage
lacunae chambers (houses chondrocytes)
matrix material which fills space between lacunae
perichondrium fibrous layer nourishes the cartilage (dense irregular connective tissue )
chondroblasts at boundary of perichondrium and cartilage proper

Glands in surrounding connective tissue:
mucus acinar gland (tracheal gland) makes mucus which “floats” on top of cilia.
serous gland with darker shallow cuboid makes thin serous fluid which bathes the cilia, allowing free movement of cilia


Elastic cartilage
Elastic cartilage

(slide 12) Elastic cartilage
(VE: fig 3-5, p 43) (ear):
Similar to hyaline cartilage, but elastin is the predominant fiber, giving the tissue great elasticity. It is prominent in cartilage which give the external ear and the eustachian tubes their structures. The Verhoeff stain specifically stains elastin blue, making it visible in this slide as blue fibers surrounding lacunae.

Here is a labeled view of elastic cartilage

Features to learn and label in your illustration

perichondrium
elastin fibers in matrix (anastomosing)
lacunae
chondrocytes


Fibrocartilage with H & E stain
Fibrocartilage with H & E stain

(slide 13) Fibrocartilage with H & E stain
(VE: 3-4, p 43) (intervertebral disc):

Fibrocartilage with aniline blue stain:
Fibrocartilage with aniline blue stain:

View this slide first at low power to see the loosely organized pulp in the center of the disc.

Multiple organized layers of collagen give this cartilage strength and allow it to absorb shock.
It ties bones together as in the pubic symphysis and intervertebral discs and serves as a shock absorber as in the menisci of the knee.
Note in the cortex that the chondrocytes are characteristically lined up in rows embedded in a matrix composed mostly of collagen fibers (little ground substance). Collagen fibers stain pink with H&E, and dark blue with aniline blue

Here is a labeled version of fibrocartilage.

(Some slides are stained with hematoxylin and eosin , others with aniline blue .)

Features to learn and label in your illustration

lacunae
chondrocytes in train-like rows
collagenous fibers, wavy and parallel in arrangement


Other images related to these specimens:

intervertebral disc
intervertebral disc

A cross section through an intervertebral disc. The outer cortex consists of fibrocartilage, the inner pulp is gel-like making the disc a tough, resilient shock absorber between the vertebra. When the cortex weakens, as when a great weight is lifted incorrectly, the pulp can cause the disc to bulge out, causing a so-called “slipped disc.”

 

 

trachea
trachea

The trachea, viewed in this exercise for its hyaline cartilage, contains interesting features:

 

 

 

mucus acinar gland
mucus acinar gland

Tracheal glands (acinar mucous glands) which produce mucus. Note that the appearance is similar in consistency to goblet cells

 

 

 

serous gland
serous gland

Serous Glands  embedded in the lamina propria.

 

 

 

pseudostratified ciliated columnar epithelium
pseudostratified ciliated columnar epithelium

And, as we saw in the exercise on epithelial tissues, the superficial most tissue in the trachea is pseudostratified ciliated columnar epithelium

 

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