There is a concomitant stoppage of respiration after initial 'catch' in inspiration.

There is a concomitant stoppage of respiration after initial 'catch' in inspiration. the Lriynx is closed and is drawn upwards. All these events result in prevention of aspiration of the vomits into the respiratory tract. The palate rises and the communication between the nasopharynx and pharynx is cut off This prevents spilling off of the vomitus into the nasopharyngeal and nasal cavity. Ant peristalsis waves may develop in the stomach or duodenum and if This develops it aids in vomiting. However, development of ant peristalsis waves is probably not essential. Vomiting center. This is situated in The medulla, close to the salivary centers. salivations therefore, is common when The vomiting center is stimulated. The vomiting center may be stimulated by a very Large variety of stimuli. Thus inflammation of malady of most of the viscera within our abdomen (gastritis. enteritis, cholecystitis etc.) heart (myocardial infarction) or ghastly disagreeable sight, smell, taste etc. can cause vomiting. Head injury and intracranial Tumor irritate The vomiting center directly by means of raised intracranial tension and cause vomiting. This type of vomiting is called "central vomiting’ Near The vomiting center at medulla There is a "central chemoreceptor trigger zone" (CTZ) which when stimulated, causes a stimulation of the vomiting center in turn. Drugs of the group of phenothiazines (e.g. chlorpromazine or largacticl'. act on this CTZ and thus inhibits vomiting. Nausea and vomiting, particularly in the morning are normally seen in early months of pregnancy and are called "morning sickness" This is due to stimulation of vomiting center by some metabolites Vomiting very often ejects undesirable substances from the stomach and Thus, saves us from Them. However, persistent vomiting also causes loss of water (dehydration and H+ ions (alkalosis) with their attendant train of sequences. MOVEMENT OF THE SMALL INTESTINE 1. Introduction. 2. The movements the different types of movements, effects of nerves and hormones on them and conditions influencing them.3. Applied Physiology. Introduction The small intestine, beginning from the first part of the duodenum and ending in the ileocecal junction, normally maintains a tone After death. this Tone disappears and as a result. The length of The small intestine (as well as that of the large intestine) increases To great extent The length of the intestine in cadavers, therefore is no index of That in life. In addition to the tone three other movements are described classifically They are - (i) segmentations. (ii) pendular movements and (iii) peristalsis. These are on the basis of the animal experiments made by Cannon (of USA) as well as Starling and Bayliss (of Great Britain) who made their studies in the beginning of 20th century or in the last phased 19th century. In 1965 G. Friedman and his colleagues reported their studies on the movements of human srnall intestine.