What is the Difference Between Serous Acini and Mucous Acini?

Serous acini and mucous acini are two types of secretory units found in exocrine glands, such as salivary glands, which play a crucial role in producing and releasing secretions. The main differences between serous acini and mucous acini are:

• Cell Types: Serous acini contain only serous cells, while mucous acini contain only mucous cells.
• Shape: Serous acini are generally spherical, while mucous acini are usually tubular.
• Secretions: Serous acini secrete a watery protein-rich fluid containing various digestive enzymes. In contrast, mucous acini secrete mucus, which is a watery solution rich in glycoproteins (or mucins) that becomes hydrated upon exocytosis to form mucus.
• Gland Composition: Some glands, such as the parotid gland, contain primarily serous acini and produce watery serous saliva. Other glands, like the submandibular and sublingual glands, contain both mucous and serous acini, making them mixed or sero-mucous glands.

In some cases, there are mixed (or sero-mucous) acini that contain a mixture of serous and mucous cells. In these acini, the serous cells form a serous demilune around the mucous acinus.

Comparative Table: Serous Acini vs Mucous Acini

Serous and mucous acini are two types of secretory units found in salivary glands. They differ in the composition of their secretions and the structure of the cells that produce them. Here is a comparison between serous acini and mucous acini:

In mixed serous-mucous acini, serous acini form a serous demilune around mucous acini. The parotid gland is an example of a serous gland, while the submandibular gland contains mixed serous-mucous acini, and the sublingual gland is majority mucous-secreting.