Which of the following is an example of feedforward mechanism?
High-Yield Explanation
Ans. (c) Shivering on exposure to cold environmentRef: Ganongs Review of Medical Physiology 25th Ed; Page No- 249* Thermoreceptors are located within the body (central Thermoreceptors) as well as in the skin surface (peripheral thermoreceptor).* Thermoreceptors within body function as conventional feedback sensor. If the CORE body temperature drops back to 37degC set point.* In contrast, thermoreceptors in the skin function as feed-forward sensor. How? Decreases in environmental temperature are rapidly sensed by skin thermoreceptors, and compensatory thermoregulatory responses are initiated before there is any appreciable fall in CORE body temperature.* Other example of feed-forward system:# Increased Heart rate and respiratory rate even before the start of exercise due to psychic stimulation.# Some rapid movement of body parts occurs so rapidly that there is not enough time for feedback control (slow). Thus brain controls these movements by feed-forward system.Extra MileThermoreceptorsReceptorsNerve fibers typeDetectsCool receptorsAdSkin cooling (<25degC)Warm receptorsCSkin warming (>35degC)Heat nociceptorsAdHot temperature (>45degC)Cold nociceptorsCCold temperature (<5degC)