Avian Uropygial Gland: A Comprehensive Guide with Interactive Labelling Practice and Quiz
Uropygial Glands in Birds – Anatomy, Physiology, Diagrams, Practice & Quiz Glossary Holocrine Secretion: A process of glandular secretion where the entire secretory cell disintegrates to release its accumulated products (lipids). Trabeculae: Connective tissue septa or "walls" that originate from the capsule and extend into the gland to provide structural support and divide it into lobes. Papilla: The small, nipple-like projection at the rear of the gland through which the oil is discharged. Preen Wick (Circlet): A specialized arrangement of small feathers (down) at the tip of the papilla that acts as a reservoir to hold oil for the bird's beak. Invagination: The folding in of a membrane or layer of tissue so as to form a pocket—essential in the development of the glandular ducts. 7-Dehydrocholesterol: A precursor sterol found in preen oil that converts to Vitamin D3 when exposed to ultraviolet (UV) sunlight. Lipid Monoesters: The primary chemic...
