The itinerary of a breakfast : a popular account of the travels of a breakfast through the food tube and of the ten gates and several stations through which it passes, also of the obstacles which it sometimes meets . ects. Whensuch an object comes in contact with theuvula a reflex action is at once produced, asthe result of which the base of the tongue isdrawn up and the object thrown forwardinto the mouth. Strong stimulation of thefauces produces coughing and gagging, bywhich solid materials may be projected for-ward with so much force as to be ejectedfrom the mouth. This is the reason why it
The itinerary of a breakfast : a popular account of the travels of a breakfast through the food tube and of the ten gates and several stations through which it passes, also of the obstacles which it sometimes meets . ects. Whensuch an object comes in contact with theuvula a reflex action is at once produced, asthe result of which the base of the tongue isdrawn up and the object thrown forwardinto the mouth. Strong stimulation of thefauces produces coughing and gagging, bywhich solid materials may be projected for-ward with so much force as to be ejectedfrom the mouth. This is the reason why it isdifficiilt to swallow a piU, for which, indeed,some practice is necessary in the case of manypersons. Now below the mouth the alimentarycanal provides no means for the mechanicalreduction of the food. Certain birds areprovided with a mill lower down—^the giz-zard,—^and in some lower species of animalsmore complicated mechanisms are providedfor grinding the food. Such animals natur-ally swallow their food entire, but in humanbeings, as well as in the horse and most othermammals, the mill is located in the mouth,and it is the duty of the soft palate to see thatthe food is completely ground and reduced to. iTMMiwfiMI Cross-section oV Papilla from Back of TongueShowin Taste Buds at A. THE TEN GATES 45 a semi-liquid state is permitted toproceed further along the digestive mastication is necessary in orderthat the saliva and the juices of the stomachand intestine may be readily brought into con-tact with every particle of food, so that eachmay do its work upon the individual food ele-ments promptly and completely. That the jaws were intended for powerfulaction is shown by the extraordinary powerwhich their muscles possess. The strength ofthe bite is seldom less than eighty pounds andsometimes reaches two hundred and fiftypounds. 2. The inspectors gate holds the food inthe mouth long enough for the nerves of tasteto exercise their functions. Pavlov, ofP
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectconstip, bookyear1920
