Saliva is exocrine.
Understanding Exocrine Glands
Exocrine glands secrete substances through ducts onto an epithelial surface. These substances aren't hormones; instead, they perform various functions directly at their site of secretion. Multiple sources confirm saliva's exocrine nature.
- The Cleveland Clinic: States that exocrine glands secrete "sweat, tears, saliva, and other substances through ducts." (https://my.clevelandclinic.org/health/body/22947-exocrine-glands)
- StatPearls: Clearly identifies salivary glands (parotid, submandibular, and sublingual) as examples of exocrine glands. (https://www.ncbi.nlm.nih.gov/books/NBK542322/)
- Medical News Today: Lists salivary glands as a prime example of exocrine glands, highlighting their role in producing saliva for digestion. (https://www.medicalnewstoday.com/articles/endocrine-vs-exocrine)
- National Cancer Institute: Defines exocrine glands as producing substances like "sweat, tears, saliva, milk, and digestive juices," releasing them through ducts. (https://www.cancer.gov/publications/dictionaries/cancer-terms/def/exocrine-gland)
- ScienceDirect: Reinforces the concept of exocrine glands secreting substances via ducts, contrasting this with the ductless endocrine glands that release hormones directly into the bloodstream. (https://www.sciencedirect.com/topics/immunology-and-microbiology/exocrine-gland)
In contrast, endocrine glands secrete hormones directly into the bloodstream, affecting distant targets. Saliva, however, is released directly into the mouth via ducts from the salivary glands, fulfilling its digestive and lubricating roles locally. The various enzymes and other components within saliva are not hormones.
