Home▸Medical Technology & Imaging Physics▸The Hiccup Reflex: Anatomy of an Involuntary "Hic"

🫁 The Hiccup Reflex: Anatomy of an Involuntary "Hic"

Explore the neural circuitry behind hiccups, from phrenic and vagal afferents converging on a brainstem hiccup center to the diaphragm spasm and glottal snap that produce the telltale sound.

Medical Technology & Imaging Physics3DModerate60 FPS

The simulator models the three-nerve reflex arc that produces a hiccup, showing how afferent signals from the phrenic nerve, vagus nerve, and sympathetic chain summate in a brainstem circuit and, once a firing threshold is crossed, trigger a diaphragm spasm followed by a precisely timed glottal closure.

🔬 What It Demonstrates

🎮 How to Use

Adjust the strength of each afferent input (gastric stretch, temperature change, carbonation) to see how they summate toward the firing threshold. Trigger a firing event to watch the diaphragm contraction and the delayed glottal closure animate in sequence, and vary the inter-signal delay to see how it reshapes the resulting sound and airflow pattern.

💡 Did You Know?

Fetuses begin hiccupping in the womb often before they take their first breath of air, a pattern many researchers cite as supporting evidence for the reflex's proposed evolutionary link to ancestral gill-breathing circuitry.

⚙ Under the hood

Explore the neural circuitry behind hiccups, from phrenic and vagal afferents converging on a brainstem hiccup center to the diaphragm spasm and glottal snap that produce the telltale sound.

hiccupsreflex-arcdiaphragmvagus-nervebrainstemneuromuscularphrenic-nerveglottis

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install