Term
| The four general functions of the Digestive System |
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Definition
-Ingestion
-Digestion (mechanical and chemical)
-Absorption
-Elimination |
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Term
| Organs of the Alimentary Canal |
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Definition
-Mouth
-Pharynx
-Esophagus
-Stomach
-Small Intestine
-Large Intestine |
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Term
| Function of the Mouth in the Alimentary Canal |
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Definition
| Recieve and mechanically digest food through mastication, some chemical digeston through saliva |
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Term
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Definition
| When saliva mixes with food in the mouth its name is changed to Bolus |
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Term
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Definition
| When Bolus and gastric juices are mixed the name is changed to Chyme |
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Term
| Three Types of Salivary Glands |
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Definition
*Parotid Glands-Lie inferrior to each ear, secrete mostly Amylase
*Submandibular Glands-located in the floof of the mouth, inside the surface of the lower jaw, secrete about 50/50 Amylase & Mucus
*Sublingual Glands- Located inferior to the tongue, secrte mostly mucus |
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Term
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Definition
-Helps mix food with saliva
-Lingual Frenulum secures it to the floor of mouth
-contains the taste buds |
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Term
| What are the 6 main TYPES of Salivary Secretions |
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Definition
-Salivary Amylase
-Lingual Lipase
-Mucin
-IgA
-Lysozyme
-Defensins |
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Term
| Uses for Salivary Secretions in Digestion |
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Definition
-Moiston Food Particles
-Begin the chemical digestion of bolus
-Dissolve food particales so that they can be tasted
-Help cleanse the mouth and teeth |
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Term
| Name and Function of the Teeth |
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Definition
General Function:The Mechanical digestion in oral cavity
-Incisors:bite off pieces of food
-Canine:Grasp and tear food
-Premolar & Molar: Grind food particles |
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Term
| Function of the Pharynx in the Alimentary Canal |
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Definition
| Passageway for food, fluids and air (no digestive role) |
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Term
| Name the Five steps of Deglutination |
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Definition
1-Upper esophageal sphicter is contracted. During the buccal phase, the tongue presses against the hard palate, forcing the food bolus into the oropharynx where the involutary phase begins (Pharyngeal-esophageal phase)
2-The ulva and larynx rise to prevent food from entering respiratory passaways. The tongue blocks off the mouth. The upper esophageal sphincter relaxes, allowing food to enter the esophagus.
3-The constirctor muslces of the parynx contract, forcing food into the esophagus inferiorly. The upper esophageal sphincter contracts (closes) after entry.
4-Food is moved through the esophagus to the stomach by peristalsis
5-The gastroesophageal sphincter opens, and food enters teh stomach. |
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Term
| Function of the Stomach in the Alimentary Canal |
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Definition
-To receive food and mix it with gastric juice
-Initiate protein digestion
-Carry on limited absorption
-Move food into the small intestine |
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Term
| Where is Bile produced and stored? |
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Definition
| It is produced by the Liver (product of hemoglobin break down with cholesterol and electrolytes) but stored in the Gallblader |
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Term
| What is Bile (composition) and function? |
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Definition
-Bile salts, bile pigments(products of hemoglobin breakdown), cholesterol, and electrolytes
-Only the bile salts have digestive functions (emulsify fats and aid in the absorption of fatty acids, cholesterol, and certain vitamins ) |
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Term
| Steps for Biles regulation and secretion (same as Pancreatic juice regulation) |
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Definition
-1.Chyme entering deudenum stimulates Cholecystokinin(CKK) secretion from duodenal enteroendocrine cells
-2.CKK AND Secritin enter the blood stream
-3.CKK enduces secretion of enzyme rich pancreatic juice. This causes secretion of HCO3- rich pancreatic juice
-4.Bile salts and secrin (to a lesser extent) transported via bloodstream stimulate liver to produce bile more rapidly
-5.CKK (via bloodstream) causes gallbladder to contractand hepatopancriatic sphincter to relax; bile enteres duodenom
-6.Durrign cephalic and gastric phases, vagal nerve stimulation causes weak contractions of the gallbladder |
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Term
| Functions of the Liver and Gallbladder in digestrion |
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Definition
-To metabolize carbohydrates, lipids, and proteins
-Store glycogen
-Filter blood
-Remove toxins
-Secrete bile |
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Term
| Function of the Pancrease in digestion |
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Definition
-Endocrine Function: To secrete glucagon and insulin (hormones)
-Exocrine Function: To secrete pancreatic juice |
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Term
| Function of Pancreatic Juices |
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Definition
-Contains enzymes that digest carbohydrates, fats, proteins, and nucleic acids
-(Pancreatic juice also neutralizes acidic chyme and causes the contents of the intestine to be basic) |
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Term
| Function of Pancreatic Amylase |
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Definition
| -Breaks down carbohydrates into disaccharides |
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Term
| Function of Pancreatic Lipase |
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Definition
| -Breaks down triglycerides into glycerol and fatty acids |
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Term
| Function of Trypsin, Chymotrypsin, and Carboxypeptidase |
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Definition
| -Proteolytic enzymes, break down proteins into peptides |
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Term
| Function of Nuclease (Pancrease) |
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Definition
| Breaks nucleic acids into nucleotides |
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Term
| Steps for Regulating Pancreatic Juice Secretion (same as Bile regulation) |
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Definition
-1.Chyme entering deudenum stimulates Chylosistokenin(CKK) secretion from duodenal enteroendocrine cells
-2.CKK AND Secritin enter the blood stream
-3.CKK enduces secretion of enzyme rich pancreatic juice. This causes secretion of HCO3- rich pancreatic juice
-4.Bile salts and secrin (to a lesser extent) transported via bloodstream stimulate liver to produce bile more rapidly
-5.CKK (via bloodstream) causes gallbladder to contractand hepatopancriatic sphincter to relax; bile enteres duodenom
-6.Durrign cephalic and gastric phases, vagal nerve stimulation causes weak contractions of the gallbladder |
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Term
| Function of the Small Intestine in the Alimentary Canal |
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Definition
-To receive chyme from the stomach and complete its digestion
-To absorb products of digestion
-To transport residues to the large intestine |
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Term
| Villi (not the same as MICRovilli) |
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Definition
| -Increase surface area for absorption and contain glands that secrete digestive enzymes (digest carbohydrates & proteins) |
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Term
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Definition
| -Microvilli on absorptive cells of mucosa bearing digestive enzymes |
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Term
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Definition
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Term
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Definition
| -Secrete large volumes of intestinal juice, a watery fluid that brings digestive products into the villi (neutral pH, no digestive enzymes) |
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Term
| The Three Brush Border Enzymes |
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Definition
-Peptidase: Breaks peptides into amino acids
-Sucrase, Maltase, and Lactase: Breaks disaccharides into monosaccharides or simple sugars
-Intestinal Lipase: Breaks fats into glycerol and fatty acids |
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Term
| What stimulates secretions in the Small Intestine? |
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Definition
| -Secretion is stimulated by gastric juice, chyme, and reflexes stimulates by distention of the small intestine wall |
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Term
| What does the Small Intestine Absorb? |
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Definition
| -Water, electrolytes, monosaccharides, amino acids, fatty acids, and glycerol |
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Term
| In the Small Intestine, What perfoms the last steps of Digestion? |
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Definition
| -Enzymes on microvilli perform the final steps of digestion |
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Term
| In the Small Intestine, Where are the substances absorbed into? |
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Definition
| -Blood capillaries in villi absorb monosaccharides, amino acids, fatty acids, and glycerol |
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Term
| Explain basic Small Intestine Movement and to where the Chyme is moved to |
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Definition
-Weak peristalsis propel chyme through the small intestine
-Segmentation slows movement down (3-10hrs for chyme to travel)
-The ileocecal sphincter joins the small intestine’s ileum to the large intestine’s cecum |
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Term
| Functions of the Large Intestine in the Alimentary Canal |
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Definition
-Reabsorb water and electrolytes from chyme
-Forms & stores feces |
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Term
| Large Intestines Microscopic Anatomy |
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Definition
-Mucosa: Simple columnar epithelium (except anal canal), no villi or digestive enzymes
-Mucosa is thicker & crypts are deeper than small intestine
-Crypts contain mucus-secreting goblet cells |
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Term
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Definition
-Includes materials that were not digested or absorbed, water, electrolytes, mucus, shed intestinal epithelial cells, and bacteria
-Color is from bile pigments
-Odor is due to by-products of bacteria living inside the digestive tract |
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Term
| Basic movement of the Large Intestine |
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Definition
-Has peristaltic movements similar to the small intestine but also has segmenting haustral contractions
-Mass movements occur two to three times a day, leading to contents to rectum (gastrocolic relfex can also occur) |
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Term
| Rate of emptying in the stomach depends on what? |
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Definition
-Depends on what you ate:
fatty foods < proteins < carbohydrates < liquids
-(the stomach has limited abrosbtion ability) |
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Term
| The Three steps of Gastric Motility and Emptying |
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Definition
-1.(The Pyloric valve is closed) Propulsion: Peristalic movement moves from the fundus toward the pylorus
-2. (The Pyloric valve is closed) Grinding: The most vigorous peristalsis and mixing action occur close to the Pylorus
-3. (Pyloric valve slightly opened) Retropulsion: The Pyloric end of the stomach acts as pump that deliver small amounts of Chyme into the duodenum, simultaneously forcing most of its contained material backward into the stomach |
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