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Definition
| Within the cell; usually in membrane-bound vesicles. |
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Definition
| Digestive process outside of the cell, within a lumen or tract. |
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Definition
| Mammals have a one-way digestive tract. |
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Definition
| Surfaces of body structures (skin, lungs, linings of nose, mouth, esophagus, stomach, intestines. Cels act as a barrier against mechanical injury, invading organisms, fluid loss. Free surface ay be ciliated. Connected to underlying connective tissue. |
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Definition
| Attaches inner surface of epithelium to connective tissue. |
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Definition
| Type of epithelium containing a single layer of cells. |
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Definition
| Type of epithelium containing multiple layers of cells. |
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| Pseudostratified epithelium |
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Definition
| Type of epithelium: single-layered but appears stratified becasue tis cells vary in height. |
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| Three types of cell shape in epithelium |
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Definition
Cuboidal
Columnar
Squamous (scale-link) |
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Definition
| specialized epithelium that lines (most) body cavities. |
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Term
| Digestion in the oral cavity |
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Definition
| Mechanical and chemical digestion of food. |
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Definition
| Breakdown of large food particles into smaller particles through biting, chewing action of teeth allowing for an increase in surface area, allowing for more efficient enzymatic action. |
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Definition
| Chemical breakdown of macromolecules into smaller molecules. Begins in the mouth when the salivary glands secrete saliva, which lubricates food to facilitate swallowing. |
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Term
| Salivary amylase (pytalin) |
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Definition
| Enzyme in saliva which hydrolyzes (some of the) starch into simple sugars. |
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Definition
| Tongue rolls the food into this ball, pushes into the pharynx. |
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Definition
| Cavity that leads food from mouth into esophagus. Functions in respiration as passageway through which air enters the trachea. |
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Definition
| Flap covering trachea which closes during swallowing, preventing food particles gowing down the wrong passageway. |
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Definition
| Muscular tube leading from the pharynx to the stomach. Moved via peristalsis. |
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Term
| Lower esophageal sphincter/cardiac sphincter |
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Definition
| Specialized ring of muscle between esophagus and stomach, allowing food to enter the stomach and prevents regurgitation. |
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Definition
| Stores and partially digests food. Lined with grastric mucosa. |
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Definition
| Within the gastric mucosa. Stimulated by nervous impulses from the brain whcih responds to food senses. Composed of secretory cells: mucous cells, chief cells, parietal cells. |
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Term
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Definition
| Secrete mucus which protects the stomach lining from acidic juices. |
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Definition
| Composed of secretions of the chief cells and parietal cells. |
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Term
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Definition
| Secrete pepsinogen, the zymogen of the protein-hydrolyzing enzyme pepsin. |
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Term
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Definition
| Secrete HCl which kills bacteria, dissolves the intercellular glue holding tissues together, and facilitates the conversion of pepsinogen to pepsin. |
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Term
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Definition
| Secrete hormone gastrin in response to presence of certain substances in food. |
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Definition
| Stimulates the gastric glands to secrete more HCl, stimulates muscular contractions of the stomach, which churns food, producing an acidic, semi-fluid mixture: chyme. |
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Term
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Definition
| muscle at the junction of stomach and the small intestine which regulates the passage of chyme into the small intestine via alaternating contractions and relaxations. |
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Term
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Definition
| Chemical digestion occurs here, divided into three sections: duodenum, jejunum, and ileum. 6m in length, highly coiled. Villi extend out of the intestinal submucosa and microvili project from surface of individual cells. Total SA=300m2 |
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Term
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Definition
| Most digestion in sm. intestine occurs in this region. Secretions of intestinal glands, pancrease, liver, gall bladder mix with the chyme, which triggers hormonal release to stimulate these secretions. |
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Term
| Maltase, lactase, sucrase, peptidases |
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Definition
| Enzymes secreted by the intestinal mucosa that hydrolyze carbohydrates and proteins. |
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Term
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Definition
| Hromone released by duodenum, stimulating the pancreas to secrete pancreatic juice. |
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Term
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Definition
| Alkaline fluid that helps neutralize chyme, and contains enzymes that digest carbs, proteins, and lipids. |
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Term
| Trypsinogen, Chymotrypsinogen. |
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Definition
Proteolytic zymogen secreted by pancrease; converted to active form, trypsin by enterokinase (via intestinal glands).
Trypsin converts chymotrypsinogen to chymotrypsin.
Both cleave proteins into polypeptides. |
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Term
| Carboxypeptidase, aminopeptidase |
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Definition
| Secreted by pancreas (activated by trypsin), and intestinal glands (respectively) which digest polypeptides into amino acids. |
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Term
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Definition
| Secreted into the boodstream by duodenum in response to chyme. Stimulate ssecretion of pancreatic enzymes and bile. |
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Term
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Definition
| alkaline fluid synthesized and secreted by the liver, stored in the gall bladder, released into duodenum. Composed of bile salts, pigments, and cholesterol. |
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Term
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Definition
| Bile salts are h20 soluble on one side and fat soluble on another, allowing for the emulsification of fat globules and to maintain them in micelles. Exposes more of the lipids' surface area to lipases. |
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Term
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Definition
| Hydrolyze molecules of fat into glycerol and fatty acids. |
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Term
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Definition
| Released if the chyme is particularly fatty, which inhibits peristalsis, slowding down release of chyme into the sm. intestine. |
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Term
| Parasympathetic nervous system and sympathetic nervous system in digestion |
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Definition
PNS stimulates digestive processes.
SNS inhibits digestive processes. |
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Term
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Definition
| Majority of absorption occurs across walls of jejunum and ileum . Monosacc's are absorbed into epithelial cells lining villi. Amino acids are absorbed into epithelium via active transport. Others diffuse directly into intestinal capillaries and enter portal circulation via hepatic portal vein. |
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Term
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Definition
| Triglycerides (fatty acids & glycerol), phosphoglycerides, cholesterol packages. Secreted into tiny lymph vessels within the villi called lacteals, where they are then processed in the bloodstream and delivered to the liver. Further repackaging allows their release into bloodstream as LDLs, VLDLs, HDLs. |
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Definition
| Tiny lymph vessels within the villi which lead to the lymphatic system. Chylomicrons are secreted into these. |
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Definition
| Occurs in small intestine. Absorbed into circulatory system. |
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Definition
| 1.5m long, three parts: cecum, colon, rectum. |
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Term
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Definition
| Blind outpocketing at the junction of the sm. and large intestines. Tip of cecum is the appendix. |
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Definition
| Vestigial structure containing lymphoid tissue that is often removed if becomes infected. |
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Definition
| Functions in absorption of salts and the absorption of any water leftover. |
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Definition
| Stores feces which consists of bacteria, water, undigested food, and unabsorbed digestive secretions. |
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Definition
| opening through which wastes are eliminated. Separated from rectum by two sphincters that regulate elimination. |
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