Addison’s disease is an adrenal insufficiency caused by infection or autoimmune destruction of the adrenal cortex. Fatigue, low blood pressure, nausea and other symptoms of the disorder suggest failure of secretion of both glucocorticoids and mineralocorticoids.

On slide 20 examine the medulla and identify the clumps of larger cells, sometimes called chromaffin cells (Fig. 20-16). These cells have same neural crest origin embryologically and are somewhat similar histologically to the autonomic ganglia found in the gastrointestinal tract. Note also the large vascular sinuses present in the adrenal medulla.

What do cells of the adrenal medulla secrete?

What histological features of the medullary chromaffin cells are similar to cells of an autonomic ganglion?

Pancreatic islets (of Langerhans) -- contain several types of peptide hormones, mostly insulin and glucagon.

Examine a section of pancreas (slides 154 and 44) and identify the islets of Langerhans (Fig. 20-17). Note the histological differences from pancreatic acinar tissue and the similarities to other endocrine tissues.

• Sketch the relationship of a pancreatic islet and the surrounding acinar tissue.
• List 3 hormones made in the pancreatic islets.
• How could the various specific secretory cells in an islet be demonstrated?

Diabetes type 1.