submucosal gland acinus

A submucosal gland acinus is the terminal secretory unit of a submucosal gland composed of mucous and serous cells arranged around a lumen.

Located deep within the submucosa of the respiratory tract, acini are organized into discrete glands beneath the mucosa of the trachea and bronchi.

The acinus secretes mucus and serous fluid that lubricates and protects the airway epithelium while trapping inhaled particles for clearance via mucociliary transport.

Multiple acini drain into collecting ducts that ultimately connect to the ciliated terminal ducts opening into the airway lumen.

Dysfunction of glandular acini occurs in cystic fibrosis where thick secretions accumulate, and excessive mucus production in chronic bronchitis leads to airway obstruction.