Vagus Nerve
Vagus nerve is NOT involved in:A) Originating in the medulla
What our notes say
- Vagus nerve is NOT involved in:A) Originating in the medulla (Biochemical Endocrinology, MBMB2234: Neurochemistry)
- Hypoglycemia stimulates vagal activity → ↑ acid secretion (if vagus nerve is intact). (CLINICAL BIOCHEMISTRY LAQs & SAQs)
- It is inhibited by norepinephrine and epinephrine, while cholinergic stimulation (such as through the vagus nerve) stimulates its release. (LECTURE 6: Pancreatic and Adrenal Hormones)
- Main nerve supplying the tentorium cerebelli: meningeal branches of the vagus nerve (Aponeurosis — Anatomy Question Bank)
- Forms toxic oligomers → spread prion-like (gut ENS → vagus nerve → medulla → brain) (Neurodegenerative Prion Diseases: CJD, Pathology & Rapid Dementia)
- The vagus nerve releases acetylcholine at the SA node, which binds to M2 muscarinic receptors, causing bradycardia and reduced cardiac output to lower blood pressure. (Basic Pharmacology - Study Guide)
Study material on Vagus Nerve
Images
Practice questions on Vagus Nerve
Damage to the vagus nerve would most directly impair which phase of gastric secretion?
- Cephalic phase.
- Gastric phase (local reflexes).
- Intestinal phase (hormonal).
- Both gastric and intestinal phases.
Answer: A. The cephalic phase of gastric secretion is entirely mediated by vagal nerve stimulation (long reflex) in response to sensory inputs like the sight, smell, or thought of food. While the vagus nerve also influences the gastric phase (e.g., via gastrin release), damage would most directly and significantly impair the cephalic phase, which prepares the stomach for incoming food. Local gastric reflexes (enteric nervous sy