Facial Nerve Anatomy Explained — Course, Branches & Lesions | Decode Anatomy

One nerve controls your smile, your blink, your tears, and your taste. But what happens when it fails? In this episode of Ace Anatomy's Decode Anatomy series, we trace the facial nerve from its functional components all the way to its clinical lesions — connecting every branch and pathway to what actually shows up in the clinic and in your exams. The facial nerve is often introduced simply as "the nerve of facial expression." But clinically, it tells a much bigger story — carrying motor fibers, sensory fibers, and parasympathetic fibers for lacrimation and salivation. 📌 What you'll learn in this video: ✅ The four functional components of the facial nerve (GVE, SVE, GSA, SVA) and where each one begins and terminates ✅ The nerve's origin and course — from the pontomedullary junction, through the internal acoustic meatus, the facial canal, and out through the stylomastoid foramen ✅ Its path through the parotid gland and division into the temporofacial and cervicofacial trunks — the pes anserinus ("goose's foot") ✅ Every named branch, in order — including the greater petrosal, chorda tympani, and the five terminal branches (with the mnemonic "To Zanzibar By Motor Car") ✅ Upper motor neuron vs. lower motor neuron facial nerve lesions — and why upper motor neuron lesions spare the forehead ✅ Bell's palsy — the clinical picture of a lower motor neuron facial nerve lesion ⏱️ TIMESTAMPS 0:00 – Hook: the nerve behind your smile, blink, tears, and taste 0:08 – Intro 0:14 – Why the facial nerve is more than "the nerve of facial expression" 0:45 – Functional components: GVE, SVE, GSA, SVA overview 1:38 – Component nuclei and their origins/terminations 2:00 – General visceral efferent fibers — pterygopalatine & submandibular ganglia 2:56 – Special visceral efferent fibers — motor nucleus and muscles supplied 3:31 – General somatic afferent fibers — geniculate ganglion, external ear 4:02 – Special visceral afferent fibers — taste sensation pathway 4:32 – Origin and course of the facial nerve 5:20 – Course through the facial canal (genu, posterior wall, stylomastoid foramen) 6:09 – Entry into the parotid gland — temporofacial & cervicofacial trunks 6:59 – Branches within the middle ear and at the stylomastoid foramen 7:26 – Terminal branches from the parotid gland 8:04 – Distribution of each branch 9:22 – Pes anserinus — why the terminal branches are named this 9:30 – Muscles supplied by each terminal branch 10:00 – Mnemonic for the five terminal branches ("To Zanzibar By Motor Car") 10:31 – Facial nerve lesions: cortical input and the facial nerve nucleus 11:52 – Upper motor neuron vs. lower motor neuron lesions explained 13:07 – Why upper motor neuron lesions spare the forehead 14:06 – Lower motor neuron lesions — the entire half of the face affected 14:38 – Bell's palsy — clinical presentation 15:05 – Recap and closing If you found this video helpful, like, share, and subscribe to Ace Anatomy. 👩‍⚕️ About Ace Anatomy Hi, I'm Dr. Divya, Founder of Ace Anatomy. On this channel, we don't memorise anatomy — we understand it. New anatomy-in-practice videos every week, built for students, medical professionals, and anyone curious about how the human body actually works. 🔔 Subscribe and hit the bell for weekly clinical anatomy, broken down simply. 🔗 More resources: https://aceanatomy.divyadsa.com/