Deglutitive inhibition:

Ans. A. Wave of inhibition preceding esophageal peristalsisOption a is correct and b is incorrect because degultitive inhibition is an inhibitory wave induced by swallowing and then a contractile wave appears. A wave of inhibition precedes a swallow- induced peristaltic contraction in the esophageal smooth muscle.Option c is incorrect because the brain stem controls the inhibition of the esophageal skeletal muscle, the smooth muscles have an intrinsic peripheral control mechanism.Option d is incorrect because local gradients of inhibitory and excitatory myenteric nerves determines the latency between swallow and contractions.Deglutition reflex:AfferentCenter/NucleiEfferent5th, 9th and 10th CN (receptor mainly in tonsillar pillars epithelium, etc.)NTS, NA-Degulitation center (areas in medulla and lower pons)(inhibit Respiratory center in medulla)5th, 7th, 9th, 10, 12th CN, few superficial cervical nerves pharyngeal and tongue muscles, etc.Mastigation reflex:AfferentCenter/nucleiEfferentVia 5th and 9th C.N. (Bolus of food in mouth)In brainstem (connection with reticular areas in brainstem taste centers, hypothalmus, amygadala and cerebral cortex near sensory area for taste and smell)Via 5th CN (muscles of mastication)Reflex inhibition of the muscles