Endocrine Histology Pancreas, Thymus and Pineal Body

Pancreas
Know the following:
Islets of Langerhans
alpha and beta cells
exocrine acinar tissue
glucagon- produced by alpha cells
insulin- produced by beta cells

Full view of Pancreas- Pancreatic islets of Langerhans are small nests of cells, arranged into curvilinear cords, scattered throughout the pancreas.

Islets are usually conspicuously paler (less intensely stained) than the acini (OR Exocrine Acinar Tissue) of the exocrine pancreas, but in any case islets differ markedly from exocrine pancreas in the arrangement of cells (cords rather than acini).

Pancreatic islets contain several endocrine cell types secreting insulin (beta cells), glucagon (alpha cells), somatostatin (delta cells), and pancreatic polypeptide (PP cells). These cells cannot be readily distinguished in routine preparations but may be identified with special stains.

Special Stains for Alpha and Beta Cells (do not need to recognize for test)

Immunoperoxidase staining can help identify the nature of the cells present in the islets of Langerhans. On the right, antibody to insulin has been employed to identify the beta cells. On the left, antibody to glucagon identifies the alpha cells.
Alpha cells secrete glucagon
Beta cells secrete insulin

Islets of Langerhans

Exocrine Acinar Tissue

Thymus:
Terms to learn:
Cortex
Medulla
Thymosin
Lymphoid tissue

Another view of Thymus

Pineal Body:
Know the following: (it's a short list)
concretions (brain sand)
melatonin