Salivary gland. Light micrograph of a section through a salivary gland. Salivary glands are divided into lobules by connective tissue (yellow). Within the lobules are secretory cells, known as acini (small purple dots). There are two types of acini; mucous-secreting acini and serous- secreting acini. Some salivary glands contain both types of cell, while others contain only one. Also within the lobules are secretory ducts (purple rings with white centre), which carry the mucus or serum out of the lobule. Saliva is an alkaline fluid that moistens food, aids swallowing and contains enzymes which start the digestive process.