Pancreas

Irregular in form it is both exocrine and endocrine in nature hence, called heterocrine gland.

Exocrine part consists of many acini with lumen (of duct) surrounded by acinar cells, which secrete digestive enzymes.

Endocrine part consists irregular heap of cells known as Islets of Langerhans with 3 types of cells secreting different hormones like :

(i) α- cells (a-cell) - Glucagon, hyperglycemic

(ii) β- cell (b-cell) - Insulin, hypoglycemic

(iii) δ- cell (d-cell) - Somatostatin, maintains balance between the insulin and glucagon as per body requirement. Rest part

remains filled with areolar connective tissue known as stroma.

Fig. T.S. of Pancreas