Epithelium/Connective Tissues Histology

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Slide 1: SEROUS GLAND

DRAWING:

 

IDEAL SLIDE:

IDENTIFICATION POINT:

1. Triangular cells with rounded nuclei.

2. Their nuclei are centrally placed.

3. Cell boundaries are indistinct.

4. Lumen of these acini is smaller than the mucous acini.

 

Slide 2: MUCOUS GLAND

DRAWING:

 

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. Tall cells with flat nuclei at their base.

2. Cell boundaries are distinct.

3. Lumen of these acini is larger than the serous acini.

4. Lightly stained and appear empty with H & E staining.

 

 

Slide 3: MIXED GLAND

DRAWING:

 

 

Slide 4: LOOSE AREOLAR TISSUE

DRAWING:

IDEAL SLIDE:

 

 

Slide 5: ADIPOSE TISSUE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. The cytoplasm of each cell is seen as a pink rim.

2. The nucleus is flat and lies to one side(eccentric).

3. In routine sections, the cells appear empty, giving it a honeycomb appearance.

 

 

Slide 6: MUCOID TISSUE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. Component of mucoid tissue is a jelly-like group substance rich in hyaluronic acid.

2. Scattered and star-shaped fibroblasts, some delicate collagen fibers, and some rounded cells.

 

Slide 7: RETICULAR TISSUE

DRAWING:

IDENTIFICATION POINTS:

1. It contains abundant reticular fibers.

2. Reticular fibers are composed of collagen type 3.

3. They differ from typical collagen fibers as follow:   • They are much finer and have uneven thickness.   • They form a network by branching, and by anastomosing with each other.   • Reticular fibers stained black with silver impregnation but type 1 collagen fibers stained brown with silver impregnation.

 

 

Cartilage Histology

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Slide 8: HYALINE CARTILAGE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. There is a presence of isogenous cell groups of chondrocytes called as cell nest.

2. Its intercellular substance appears to be homogenous.

3. In H & E staining, the matrix is stained blue.

4. Around cell nests, the matrix stains deeper than elsewhere is called the territorial matrix or lacunar capsule.

5. The pale staining matrix separating cell nests is the interstitial matrix.

6. Chondrocytes increase in size from periphery to center.

7. Near the surface of the cartilage the cells are flattened and merge with the cells of the overlying connective tissue. This connective tissue forms the perichondrium.

8. Using special techniques, it can be shown that many collagen fibers are present in the matrix.

 

Slide 9: ELASTIC CARTILAGE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. The main difference between hyaline cartilage and elastic cartilage is that instead of collagen fibers, the matrix contains numerous elastic fibers that form a network.

2. The elastic fibers are difficult to see in H & E stained sections, but they can be clearly visualized if special methods for staining elastic fibers are used.

3. Elastic cartilage is characterized by the presence of chondrocytes within the lacuna surrounded by bundles of elastic fibers.

 

Slide 10: FIBROCARTILAGE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. Presence of prominent collagen fibers arranged in bundles with rows of chondrocytes intervening between the bundles.

2. Perichondrium is absent.

3. This kind of cartilage can be confused with the appearance of a tendon. However, the chondrocytes in fibrocartilage are rounded but, in a tendon, fibrocytes are flattened and elongated.

4. The collagen in fibrocartilage is different from that in hyaline cartilage in that it is type 1 collagen and not type 2.

 

Slide 11: Transverse Section OF COMPACT BONE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. A transverse section through compact bone shows ring-like osteons.

2. At the center of each osteon there is a Haversian canal.

3. Around the canal there are concentric lamellae of bone amongst which there are small spaces called lacunae.

4. Delicate canaliculi radiate from the lacunae; these contain cytoplasmic processes of osteocytes.

5. Interstitial lamellae fill intervals between Haversian systems.

6. Near the surface of compact bone, the lamellae are arranged in a parallel manner. These are circumferential lamellae.

7. Volkmann`s canal interconnecting the adjacent Haversian canal may be seen.

Bone Histology

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Slide 12: Longitudinal Section of COMPACT BONE

DRAWING:

IDEAL SLIDE:

 

 

Slide 13: DEVELOPING BONE

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

In the zone of resting cartilage, the cells are small and irregularly arranged.

In the zone of proliferative cartilage, the cells are larger and undergo repeated mitosis.

As they multiply, they come to be arranged in parallel columns, separated by bars of intercellular matrix.

In the zone of calcification, the cells become still larger and the matrix becomes calcified.

Next to the zone of calcification, there is a zone where cartilage cells are dead and the calcified matrix is being replaced by bone.

 

 

Slide 14: Longitudinal Section OF TENDON

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. Presence of collagen fibers arranged in orderly fashion parallel to each other.

2. In the longitudinal section of the tendon, the fibroblasts and their nuclei are seen to be elongated.

3. Ground substance is less in amount.

 

Slide 15: Transverse Section of TENDON

DRAWING:

IDEAL SLIDE:

IDENTIFICATION POINTS:

1. In transverse sections, the fibroblasts are stellate shaped.

2. Ground substance is less in amount.