Lab Notes - Specialized Connective Tissue: cartilage & bone

Items to recognize for this module:

CARTILAGE ITEMS	BONE ITEMS
hyaline cartilage fibrocartilage cartilage lacunae chondrocytes isogenous groups cartilage matrix perichondrium	compact bone (transverse section) cancellous bone osteon (transverse section) interstitial lamella (transverse section) boney trabeculae bone lacunae canaliculi osteocytes osteoclasts periosteum Havesian canals (transverse section) Volkmann canals (transverse section) Howship lacuna

Station # 1 HYALINE CARTILAGE (go to top of page)

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SLIDE 6.42
trachea (sagittal section)

AT LOW MAGNIFICATION OBSERVE THE FOLLOWING:

• ON THE LEFT EDGE IS A SOMEWHAT THIN (PROBABLY PSEUDOSTRATIFIED) EPITHELIUM
• ON THE RIGHT EDGE IS MOSTLY FAT CELLS
• IN THE MIDDLE ARE SEVERAL DARK PURPLE BLOBS WITH SMALL HOLES AND SURROUNDED BY A THIN LAYER OF PINK COLORED CONNECTIVE TISSUE.

The PURPLE BLOBS are pieces (or chunks) of HYALINE CARTILAGE from the trachea.

AT MEDIUM MAGNIFICATION, NOTE THAT THESE CHUNKS ARE LOCATED AMONG LOTS OF FAT CELLS AND THE PINK BAND SURROUNDING THE HYALINE CARTILAGE WHICH IS THE PERICHONDRIUM)

QUESTIONS:

What are the clusters of chondrocytes called?

What type of connective tissue is the perichondrium made of?

What type of connective tissue cells are in the perichondrium?

What type of connective tissue is the cartilage located in (ie not the actual perichondrium)?

Are there any glands visibly present in the connective tissue?

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Station #2 CHONDROCYTE (go to top of page)

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SLIDE 6.42
trachea (sagittal section)

THE POINTER (AT HIGH MAGNIFICATION) SHOULD BE ON ONE CHONDROCYTE.

IN THE BOX IS AN ISOGENOUS GROUP OF FOUR CHONDROCYTE CELLS.

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Station #3 PERICHONDRIUM (go to top of page)

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Slide # 5.35
esophagus and larynx (ls)
This is a piece of hyaline cartilage that forms part of a tracheal ring. There are a couple transversely cut pieces of cartilage seen in the connective tissue.

AT HIGH MAGNIFICATION, THE POINTER IS ON THE PERICHONDRIUM.

QUESTIONS:

What type of fibers are in the perichondrium?

What cells make the fibers of the perichondrium?

 

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Station #4 fibrocartilage (go to top of page)

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SLIDE 12.31
tendon and bone

At low and medium power:

TO THE FAR LEFT, OBSERVE THE BRIGHT PINK DENSE REGULAR CONNECTIVE TISSUE. Note the tightly packed fibers and thin elongated nuclei.

TO THE FAR RIGHT, OBSERVE THE PURPLE MASS OF MATERIAL WITH CHONDROCYTES BUT WITHOUT DISTINCT FIBERS.

At high magnification, observe the pale pink and purple fibers with some scattered chondrocytes between fibers. This is the fibrocartilage.

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Station #5 HAVERSIAN CANAL (go to top of page)

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SLIDE #93 W 3293
Bone decalcified (c.s. & l.s.)
This is piece of bone that has been specially treated to remove the hard mineral salts and thereby leave the organic matrix and some cells.

AT LOW AND MEDIUM MAGNIFICATION OBSERVE THE FOLLOWING:

THE MUSCLE AND CONNECTIVE TISSUE COVERING TO THE RIGHT, THE PINKISH COLORED COMPACT BONE IN THE MIDDLE AREA, AND THE BONE MARROW TO THE LEFT SHOWING NUMEROUS SCATTERED FAT CELLS SURROUNDED BY LOTS OF PURPLE BLOOD PRECURSOR CELLS.

AT HIGH MAGNIFICATION THE LARGE SPACE AT THE POINTER IS A HAVERSIAN CANAL. THE SMALLER SPACES SURROUNDING THE HAVERSIAN SYSTEM ARE LACUNAE WHICH HAVE OSTEOCYTES IN THEM.

ALONG THE RIGHT EDGE OF THE COMPACT BONE, NOTE THE CIRCUMFIRENTIAL LAMELLA AND DENSE CONNECTIVE TISSUE THAT IS THE PERIOSTEUM.

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Station #6 HAVERSIAN CANAL SURROUNDED BY LAMELLA (go to top of page)

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Slide # 2.74 (93 W 6140)
ground bone (transverse section)

AT THE POINTER IS A HAVERSIAN CANAL SURROUNDED BY THE CONCENTRIC LAMELLA RINGS (OSTEONS).

• This is dried bone without organic matrix so it is unstained.
• The spaces are empty and generally appear black.
• The round black spaces are for Haversian canals, the small oval black spaces in the lamella are lacuna, and the thin black lines radiating out from the lacuna are canaliculi.

QUESTIONS:

What structures are located in the Haversian canals?

 

What structures connect Haversian canals to the external surface?

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Station #7 BONE LACUNAE (go to top of page)

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Slide # 2.74 (93 W 6140)
ground bone (transverse section)

AT THE POINTER IS A BONE LACUNAE.

QUESTIONS:

What category of bone cells reside in the lacunae?

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Station #8 CANALICULI (go to top of page)

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Slide # 2.74
ground bone (transverse section)

AT THE POINTER IS A CANALICULI.

THEY APPEAR TO BE SMALL CRACKS WITHIN THE BONE MATRIX.

QUESTIONS:

What structures are in the canaliculi?

 

What do the structures in the canaliculi contact?

Station #9 HAVERSIAN CANAL CUT LONGITUDINALLY (go to top of page)

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SLIDE # 2.75 (93 w 6143)
Ground bone (longitudinal sec.)
The piece of bone is oriented length wise, so the Havesian Canals (which are the major type of canal in compact bone) appear oriented lengthwise in a longitudinal piece of bone.

THE POINTER IS ON A HAVERSIAN CANAL CUT LONGITUDINALLY.

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Station #10 VOLKMANN CANAL CUT TRANSVERSELY (go to top of page)

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SLIDE # 2.75 (93 w 6143)
Ground bone (longitudinal sec.)

AT MEDIUM MAGNIFICATION, THE POINTER IS ON A VOLKMANN CANAL CUT TRANSVERSELY.

The Volkman Canal in this section is cut transversely because the piece of bone is oriented length wise and therefore the Haversion canals are running longitudinally. This means that since the Volkeman Canals are orinented perpendicularly to the Haversian Canals, they get cut cross wise when the piece of bone is longitudinally oriented.

The elongated oriented structures are longitudinally oriented Haversian Canals.

Station #11 OSTEOBLASTS (go to top of page)

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SLIDE 6.1
nasal septum (sagittal section)
This is a very thin piece of flat bone from the nasal septum.The bone is the bright pink substance running vertically in the middle of the specimen. This bone has white space in the middle of it which is the bone marrow area.

AT THE POINTER ARE OSTEOBLASTS (Here and on the microscope slide).

THEY ARE CUBOIDAL SHAPE CELLS THAT LINE UP ON EITHER THE INSIDE OR THE OUTSIDE SURFACE OF THE BONE MATRIX.

AT THE ARROWHEAD ARE OSTEOCYTES

THE CELLS ACTUALLY WITHIN THE SUBSTANCE OF THE PINK BONE MATRIX (unmarked on the microscope slide) ARE THE OSTEOCYTES.

QUESTION:

What are these cells doing?

Will these cells be found in lacunae?

 

 

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Station #12 OSTEOCLAST (go to top of page)

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SLIDE 6.1
nasal septum (sagittal section)
This is a very thin piece of flat bone from the nasal septum.The bone is the bright pink substance running vertically in the middle of the specimen. This bone has long white space in the middle of it which is the bone marrow area.

BETWEEN THE POINTERS IS A HOWSHIP LACUNA WITH ONE LARGE OSTEOCLAST CELL (At the pointer on the microscope slide).

THE HOWSHIP LACUNA IS A SMALL CONCAVITY ON THE SURFACE OF BONE.

THE OSTEOCLASTS ARE FAIRLY LARGE CELLS THAT TYPICALLY ARE SEEN TO HAVE MULTIPLE CELL NUCLEI. THEY OFTEN APPEAR AS A BIG JUMBLED MASS OF CELLS ON THE BONE MATRX SURFACE.

The cells within the substance of the matrix are the osteocyte cells.

Questions:

What is the function of an osteoclast cell?

 

What organelles should be prominent in it?

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