THE OESOPHAGUS AND STOMACH 



105 



DEGLUTITION 



Food collected into a bolus by tongue and cheeks. 

 Glided between tongue and palate to back of 



mouth. 



Voluntary. Or may be performed unconsciously. 

 Muscles contract at back of the mouth. 

 Larynx and pharynx raised and carried forward. 

 Glottis closed by the epiglottis. 

 2. -i Posterior nares shut off. 



Pharynx receives food and contracts above it, 



forcing it down into the (esophagus. 

 \ Involuntary. 



I Food forced down the oesophagus by the wave-like 

 g J contraction of the muscular fibres just above it. 

 I Thus carried into the stomach. 

 ( Involuntary. 



Coats 



Motions 



Glands 



1. Outer 

 Peritoneal 



2. Muscular, 



3. Areolar 



4. Mucous 



Cause food to 

 revolve 



Tubular. 



A serotis membrane. 



Outer longitudinal fibres. 



Middle circular fibres. 



Inner oblique fibres. 



Composed of loosely-woven fila- 

 ments. 



Smooth, soft, and level. 



Drawn up into folds when not dis- 

 tended. 



Composed almost entirely of tubulai 

 peptic or gastric glands. 



Very pale when inactive. 



Turns bright pink on introducing a 

 substance into the stomach. 



From cardiac orifice to pylorus along 

 the greater curvature. 



From pylorus to cardiac orifice along 

 the lesser curvature. 



GASTBIC 

 FLUID 



Contains 



. J Open at the surface of the mucous membrane. 



( Secrete mucus and gastric juice. 

 General properties Clear, liquid, saltish, acid. 

 Quantity secreted daily 10 to 20 pints. 

 ( Water. 

 Pepsin. 



Common salt and other salts. 

 Hydrochloric acid. 

 Dissolves nitrogenous foods. 

 No action on starchy foods. 

 No action on fats ; but 

 Dissolves the albuminous walls of the fat 

 cells, also the tissue which binds the 

 cells together, thus liberating minute 

 globules of fat. 



Converts albuminoids into diffusible pep- 

 tones. 



Converts foods into chyme. 

 Coagulates certain albuminous foods before 



digesting them. 

 Acts as an antiseptic. 



* Action. 



