Heparin is secreted by

• mast cell

• alveolar cell

• plasma cell

• goblet cell

A.

mast cell

Heparin is released from mast-cells. It is an anticoagulant which prevents activation of prothrombin. 

Alveolar cells secrete pulmonary surfactant to lower the surface tension of water and allows the membrane to seperate, therefore increasing its capability to exchange gases.

Plasma cells are WBCs or White Blood Cells secrete large volumes of antibodies.

Goblet cells secrete mucus in order to protect the mucous membranes where they are found.