Difficulty: Easy
Correct Answer: Hormones (as functional secreted endocrine hormones)
Explanation:
Introduction:Saliva facilitates digestion, oral lubrication, and host defense. This question tests recognition of the principal constituents of saliva and identification of what is not a standard component secreted by salivary glands.
Given Data / Assumptions:
Concept / Approach:Differentiate between substances synthesized/secreted by salivary glands versus systemic hormones that may diffuse into saliva. Enzymes like amylase and protective factors like IgA and lysozyme are core salivary components, whereas endocrine hormones are not secreted by these glands for physiological action in the mouth.
Step-by-Step Solution:
List normal constituents: water, electrolytes, bicarbonate, mucins, amylase, lipase (minor), lysozyme, lactoferrin, IgA.Identify the item that does not fit: endocrine hormones produced for systemic signaling.Select hormones as the exception.Verification / Alternative check:Clinical saliva tests detect steroid hormones, but these reflect plasma diffusion, not glandular production for local function.
Why Other Options Are Wrong:
b) Amylase initiates starch digestion in the mouth.c) Lysozyme and related enzymes provide antimicrobial defense.d) Secretory IgA protects mucosal surfaces.e) Mucins lubricate; bicarbonate buffers oral pH.Common Pitfalls:Confusing detectability in saliva with being a secretory product of salivary glands.
Final Answer:Hormones (as functional secreted endocrine hormones).
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