| Lab 22 Endocrine System: 1) Index 2) Introduction 3) Things to Identify 4) Pituitary Gland 5)Thyroid Gland 6) Parathyroid Gland 7) Adrenal Cortex 8) Adrenal Medulla 9) Pineal Gland 10) Practical |
|
Adrenal Gland (Cortex) |
|
# 221 - Adrenal gland, rabbit, H&E, 1.5mm # 162 - Adrenal gland, cat, medulla and cortex, H&E |
|
The adrenal gland is enclosed by a thick, distinct capsule of dense CT which sends trabeculae into the cortex which is divided into three zones (identify each zone on your slides). 1. zona glomerulosa The zona glomerulosa is the outer zone lying immediately under the capsule. It consists of fairly dark small cells arranged in closely packed groups or short arching cords. Between these looping cords of cells are reticular fibers which serve as the framework (stroma) of this organ. This peripheral layer produces mostly mineralocorticoids, primarily aldosterone. 2. zona fasciculata The major portion of the cortex is occupied by a middle zone where the cells are arranged in fairly straight, long cords of cells. These cords are separated by sinusoids. Can you see any endothelial cell nuclei bulging into the sinusoids. This widest, palest layer of the adrenal cortex contains larger highly vacuolated cells which contained lipids (loss of these lipids in fixation give them a "holey" appearance hence their name "spongiocytes"). What type of capillaries are found here? 3. zona reticularis The inner zone of the cortex is adjacent to the medulla and has cells arranged in an irregular array of short branching and anastomosing clumps. Is vascularization rich or sparse in this zone? The reticularis cells, which are not vacuolated, contain yellowish granules which are probably lipofuchsin. |
|
Adrenal Gland (cortex) |
 |
This is a low power image of the Adrenal Gland Cortex. In it you can see the three layers that make up the cortex. The outer most layer, which is called the Zona Glomerulosa indicated by the blue arrow, has a characteristic darker stain that borders the entire edge of the cortex. It is responsible for producing Aldosterone. The next layer is the Zona Fasciculata indicated by the black arrow. Besides staining lighter than the zona glomerulosa, it begins to show parrallel cords or sinuses which are characteristic of it. The inner most layer of the cortex is the Zona Reticulosa indicated by the yellow arrow. When you get to this layer you lose the parallel cords of the zona fasciculata and just forms a large reticular network, hence the name. Blue arrow - Zona Glomerulosa Black arrow - Zona Fasciculata Yellow arrow - Zona Reticulosa |
|
This is a closer look at the cortex of the Adrenal Gland. The red arrow is pointing to the Zona Glomerulosa. Again notice how the entire border of the cortex where this zone is, is stained darker. The blue arrow is pointing to the area underneath of the zona glomerulosa, the Zona Fasciculata. The yellow arrows are indicating the direction of the cords and sinuses that are present in this zone which is the identifying characteristic of it. Red arrows - Zona Glomerulosa Blue arrows - Zona Fasciculata Yellow arrows - Parallel cords or sinuses
Here is a closer look at the make up of the Zona Fasciculata. The red arrows are pointing to the nuclei of the cells found there called, Spongiocytes. The blue arrows help visualize the parallel Sinuses that are found in this zone. Blue arrows - Parallel Sinuses of Zona Fasciculata Red arrows - Spongiocytes
This is a close look at the Zona Reticulosa. Notice how you lose those parallel sinuses that are present in the zone right above it. The red arrows are pointing to the cells that make up this zone. Red arrows - Cells of Zona Reticulosa |
Zona Glomerulosa & Fasciculata
Zona Fasciculata
Zona Reticulosa |
