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62 Cards in this Set
- Front
- Back
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disintegration of the naturally occurring foodstuff into absorbable forms |
Digestion |
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There are two factors in digestion: |
Primary and Secondary Factor |
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different enzymes found in the juices of the different portions of the digestive tract |
Primary factor |
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Give some examples of Secondary factor in digestion:
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- Cooking - Mastication - movements of the stomach and intestines or what is known as peristalsis. - absorption from the intestines, - autodigestion |
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the physical movement and breakdown of food which includes: |
-Swallowing -Peristalsis in stomach -contraction of the small intestine -contraction of the large intestine -defecation reflex |
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Bolus is pushed toward the pharynx Voluntary movement |
Buccal stage |
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-Bolus (masticated food with saliva) to pharynx to esophagus to stomach -Involuntary movement |
Pharyngeal and esophageal stage |
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Mixes contents and forces chime thru the pylorus
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Peristalsis in the stomach |
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Three waves travel down the stomach one at a time
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Peristalsis in the stomach |
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In peristalsis the three waves, Each beginning every how many seconds near the midpoint of the stomach, lasting about how many minutes ?
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20 seconds and 1 minute |
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Feedback from the ________ regulates gastric emptying.
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duodenum |
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2 mechanisms that inhibit gastric motility |
1. Entrogastric reflex which is neuronal 2. Entrogastrone which is hormonal |
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– partially digested food with gastric juices or mixed with gastric juices
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Chyme |
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Mix with saliva ? |
Bolus |
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What are the 2 phenomenom in the contraction of the small intestine |
Segmenting and Gastroileal reflex |
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rhythmic contractions along a section dividing it into segments |
Segmenting |
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Primarily a mixing action |
Segmenting |
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– the increase in ileal peristalsis and frequency of opening of the ileocecal valve due to the ingestion of food |
Gastroileal reflex |
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2 contraction of the large intestines |
-Haustra -Gastrocolic reflex |
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simultaneous contraction of circular and longitudinal muscle
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Haustra |
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– infrequent (twice a day) mass movement transferring contents from proximal to distal colon and into the rectum
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Gastrocolic reflex |
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Occurs shortly after meal |
Gastrocolic reflex |
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a. Distention of rectum triggers intense peristaltic contractions of colon and rectum and relaxation or internal anal sphincter |
Defecation Reflex |
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b. Reflex preceded by voluntary relaxation of external sphincter and compression of abdominal contents |
Defecation reflex |
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DIGESTION in the MOUTH: |
Chemical and Mechanical |
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Mechanical or Chemical; Chewing or mastication
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Mechanical |
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Mechanical or Chemical: Food manipulated by tongue, ground by teeth, and mixed with saliva
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Mechanical |
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Mechanical or Chemical ? • Forms bolus |
Mechanical |
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Mechanical or Chemical: hydrolysis of starch by salivary amylase(ptyalin)
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Chemical |
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Mechanical or Chemical: takes place in the buccal cavity and to a certain extent in the fundic end of the stomach |
Chemical |
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SALIVARY GLANDS RELEASE SALIVA: |
-ordinarily, just enough is secreted to keep mouth and pharynx mosit and clean-when food enters mouth, secretion increase to lubricate , dissolve, and begin chemical digestion. |
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Colorless slightly viscid, opalescent fluid which is a mixture of secretions of the three pairs of salivary glands
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Saliva |
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three pairs of salivary glands and their location |
Parotid gland- behind the ears Sublingual gland - tounge Submandible gland- mandible |
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section is watery and rich in ptyalin |
Parotid gland |
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secretion is more viscid containing mucin and poorer in ptyalin |
Sublingual gland |
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Organic component of saliva ? |
Water, ptyalin, & mucin |
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Factors influencing the secretion of saliva |
Psychic Mechanical Chemical |
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Identify what Factors influencing the secretion of saliva: Thinking what you are going to eat. |
Psychic factor |
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Identify what Factors influencing the secretion of saliva: Presence of food in the mouth. |
Chemical factor |
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Identify what Factors influencing the secretion of saliva: Chewing of gum |
Mechanical factor |
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Average secretion per day? |
1500cc or ml |
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Percent of organic components of saliva |
99.42 % water 0.58 % solid |
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Organic and inorganic of saliva |
o 2/3 = org. matter (mucin, ptyalin,urea, glucose, lactic acid…)-o 1/3 = inorg. Salts (Cl-, HCO3 of Na, K, - -Ca, SO4 |
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(active stimulation) ph of saliva |
7- 7.3 |
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(resting saliva) ph of saliva
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6.4-6.9 ph |
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moisten and reduce the foods into a consistency suitable for swallowing |
Saliva |
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SALIVARY AMYLASE Also known as ? |
Ptyalin |
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Endoamylase which acts only on the? |
Alpha 1,4-glycosidic linkages |
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Salivary amylase activators: |
Cl- & Br-; I- & NO3 |
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Splits starch into the disaccharide maltose |
Salivary amylase or ptyalin |
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SALIVARY AMYLASE is inactivated by ? |
Pepsin |
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HYDROLYSIS OF STARCH/POLYSACCHARIDES |
>Starch>Soluble starch>Amylodextrin>Erythrodextrin>Achrodextrin>dextrin>Maltose |
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Starch+ iodine |
Black |
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Sol. Starch + iodine |
Black |
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Amylodextrin + iodine |
Purple |
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Erythrodextrin + iodine |
Red |
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Achrodextrin + iodine |
Colorless |
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Dextrine + iodine |
Colorless |
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Maltose+ iodine |
Colorless |
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Positive and negative result of iodine |
+ black to violet - yellow or no change |
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Identify the result: |
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Positive and negative result for benedict test |
+ blue - green to orange |
