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.
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.
Sliders for phrenic, vagal, and sympathetic afferent strength; a threshold indicator for the brainstem hiccup circuit; a trigger button to fire the reflex; and a delay control for the interval between diaphragm contraction and glottal closure.
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.
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.
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.
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.
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.