Term
| What is the function of the digestive system? |
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Definition
| takes in food, breaks it down to the nutrient molecular level, absorbs them into the bloodstream, rids the body of indigestible remains |
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Term
| What 2 categories do digestive system organs fall under? |
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Definition
1. Alimentary canal
2. Accessory organs |
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Term
| Alimentary Canal (aka Gastrointestinal Tract or gut) |
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Definition
| Continuous tube that winds through the body where food is digested and absorbed |
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Term
| Accessory digestive organs |
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Definition
| Secrete enzymes to help with digestion or contribute to breakdown of food (teeth, tongue, salivary glands, gallbladder, liver, pancreas) |
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Term
| 6 Steps of Digestive Process |
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Definition
1. Ingestion
2. Propulsion
3. Mechanical Digestion
4. Chemical Digestion
5. Absorption
6. Defecation |
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Term
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Definition
| Entrance of food into the GI tract, usually by mouth |
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Term
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Definition
| Includes swallowing and peristalsis - wave of smooth muscle contraction to push food along GI tract |
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Term
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Definition
| Physically preparing food for chemical digestion (chewing, mixing of food, churning in stomach) |
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Term
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Definition
| Breaks food down to the building block molecules (fats to fatty acids, starches to glucose, proteins to amino acids) |
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Term
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Definition
| Passage of digested molecules, vitamins, minerals, and water into blood and lymph; on the average, up to 10L of food, water, and GI secretions enter the alimentary tract daily |
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Term
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Definition
| Elimination of indigestible substances through anus in the form of feces |
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Term
| 2 Mechanisms that control the digestive system |
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Definition
1. Variety of mechanical and chemical stimuli in walls of tract (stimulate or inhibit digestion)
2. Nerves along tract and endocrine glands (controls both intrinsic and extrinsic) |
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Term
| The Mouth/Oral Cavity/Buccal Cavity |
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Definition
| lined with mucus and stratified squamous epithelium (for lots of friction), boundaries are the lips, cheeks, tongue, and palate. |
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Term
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Definition
| Anterior opening of mouth |
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Term
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Definition
| Posterior opening to mouth |
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Term
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Definition
| skeletal muscle surrounded by skin, keep food between teeth for chewing, used in speech |
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Term
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Definition
| red area of lips, where keratinized skin meets the mucous layers, translucent – see red from blood vessels |
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Term
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Definition
| roof of mouth – both hard palate (anterior, bony) and soft palate (muscle, posterior). |
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Term
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Definition
| for tongue to push food against when chewing\ |
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Term
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Definition
| for tongue to push food against when chewing |
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Term
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Definition
| includes uvula, closes off nasopharynx when we swallow |
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Term
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Definition
| occupies the space of the oral cavity, “tied” to the floor of mouth, made of skeletal muscle, constantly repositions food between teeth while chewing |
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Term
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Definition
| ball/mass of food and saliva pushed into pharynx by tongue |
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Term
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Definition
| parotid, sublingual, submandibular – produce saliva |
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Term
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Definition
1. Cleanses mouth
2. Dissolves food so it can be tasted by taste buds
3. Moistens, lubricates food and helps form the bolus
4. Contains enzymes that begin the breakdown of starches into sugars
5. Contains chemicals/antibodies to protect against microorganisms |
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Term
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Definition
| lie in sockets of the gum covered jaw bones, used to masticate or chew food; First teeth to grow – baby or deciduous; Permanent – grow in until the age of 25, 32 of them; classifies by shape – incisors, canines, premolars, molars; Several layers – enamel, dentine, pulp in center |
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Term
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Definition
| complicated process involving 22 muscles, occurs in 2 phases: Buccal phase and Pharyngeal-esophageal phase |
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Term
| Buccal phase (deglutition) |
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Definition
| occurs in mouth and is voluntary, tongue pushes on hard palate, tongue contracts and pushes bolus into oropharynx, then becomes involuntary reflex |
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Term
| Pharyngeal-esophageal Phase |
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Definition
| controlled by the swallowing center in the brain (the pons and medulla; Breathing inhibited, tongue blocks off mouth, soft palate blocks off nasopharynx, epiglottis covers trachea, esophageal muscles and sphincters relax to open esophagus |
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Term
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Definition
| muscular tube about 10 inches long, flattened, and collapsed when not involved in food propulsion; runs behind heart, through mediastinum, through the diaphragm; Joins the stomach at the cardiac orifice; Has 4 layers: stratified epithelial layers, mucus, smooth muscle, skeletal muscle, fibrous layers |
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Term
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Definition
| gastroesophageal reflux disease (GERD; Burning pain when acids and enzymes from stomach are released up into esophagus (overeating, exercise, stress) |
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Term
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Definition
| weakening of the cardiac sphincter (muscle) around the cardiac orifice – allows stomach to come up through diaphragm, allows fluids from stomach to enter esophagus, especially when lying down |
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Term
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Definition
| Where GI Tract expands, forms a temporary “storage tank” where chemical breakdown of proteins begins and where food is converted to a creamy paste called chyme; Varies in size from 6-10 inches long but diameter and volume depends on how much food is consumed |
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Term
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Definition
| large, longitudinal folds in stomach (what you hear when stomach growls) |
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Term
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Definition
| Cardiac region, fundus, body, pyloric region, greater curvature, lesser curvature |
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Term
| Cardiac region of stomach |
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Definition
| aka cardia – area surrounding the cardiac orifice where food enters from the esophagus |
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Term
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Definition
| dome shaped part beneath the diaphragm, bulges upward |
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Term
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Definition
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Term
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Definition
| has 3 parts – pyloric antrum, pyloric canal, and the pylorus – continuous with the duodenum of the small intestine, has pyloric sphincter that keeps stomach closed |
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Term
| Greature curvature (stomach) |
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Definition
| convex, inferior, lateral surface |
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Term
| Lesser curvature (stomach) |
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Definition
| concave, superior, medial surface |
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Term
| 2 membranes that tie the stomach to other organs and to the body wall attached to the curvatures |
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Definition
| Lesser omentum and greater omentum |
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Term
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Definition
| from liver to lesser curvature |
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Term
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Definition
| from stomach, drapes over the small intestine – filled with lymph cells and fat cells, and drapes over the body like an apron. |
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Term
| 3 layers of smooth muscle (stomach) |
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Definition
| longitudinal, circular, and oblique – allows stomach to churn and mix food as well as peristaltic movements |
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Term
| Interior glands and secretions (Stomach) |
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Definition
| Mucous cells, Parietal cells, Chief cells, Enteroendocrine cells |
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Term
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Definition
| produces 2 layer thick barrier of mucous to protect stomach wall |
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Term
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Definition
| make and secrete HCl and intrinsic factor |
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Term
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Definition
| to kill germs, helps break down proteins, allows enzymes to function |
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Term
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Definition
| needed to absorb vitamin B |
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Term
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Definition
| make pepsinogen, which forms pepsin – enzyme to digest proteins |
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Term
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Definition
| release a variety of chemicals and hormones (histamins, serotonin, gastrin, etc.) that help stimulate digestive system, regulate stomach action |
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Term
| 3 subdivisions of small intestine |
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Definition
| the duodenum, the jejunum, and the ileum |
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Term
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Definition
| shortest section, but the most features, curves around pancreas, where the pancreatic and bile duct (from liver) both empty |
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Term
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Definition
| between the duodenum and the ileum, coils in the center part of abdominal cavity. |
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Term
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Definition
| last part of the small intestine, joins the large intestine |
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Term
| 3 structural features to increase surface area in small intestine |
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Definition
| Plicae circulares, Villi, microvilli |
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Term
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Definition
| deep folds in mucus lining |
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Term
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Definition
| projections that give the interior of the small intestine a velvety texture, contain smooth muscle to help pulsate and mix contents into texture for better absorption |
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Term
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Definition
| In villi; lymph vessels to absorb nutrients as well as blood vessels. |
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Term
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Definition
| mostly water, antimicrobial chemicals, mucous, and bicarbonate chemicals to neutralize acid from stomach (secreted from intestinal glands between villi) |
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Term
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Definition
| tiny projections on surface of each cell in the villi to increase surface area even more |
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Term
| 3 functions of large intestine |
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Definition
| to absorb water from wastes, temporarily holds wastes in rectum, eliminate solid wastes from body (feces) |
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Term
| 3 features not seen in other organs (large intestine) |
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Definition
| Teniae coli, Haustra, Epiploic appendages |
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Term
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Definition
| 3 bands of smooth muscle that run longitudinally, no circular muscles. |
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Term
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Definition
| pocket-like sacs along the length (caused by teniae coli) |
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Term
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Definition
| fat-filled pouches that hang from the surface (function undetermined) |
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Term
| 5 subdivisions of the large intestine |
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Definition
| Cecum, Appendix, Colon, Rectum, Anal canal |
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Term
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Definition
| sac-like pouch at the beginning of the large intestine (at the ileocecal valve) |
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Term
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Definition
| (aka vermiform appendix) wormlike small tubular pouch, contains masses of lymphoid tissue, used from immunity, but often gets infected with bacteria that get get trapped in its twisted shape |
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Term
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Definition
| bulk of large intestine – has 4 distinct areas – ascending, transverse, descending, sigmoid. |
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Term
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Definition
| lies in front of sacral vertebrae where feces are temporarily stored. |
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Term
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Definition
| lies outside pelvic cavity, opens to body exterior, controlled by muscles (both smooth and skeletal) |
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Term
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Definition
| Inside large intestine; most are harmless or even beneficial – aid in the digestion of cellulose, manufacture vitamin B and K, but produce gas |
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Term
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Definition
| when food is rushed through the large intestine – water isn’t absorbed |
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Term
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Definition
| when food remains in colon too long, too much water is absorbed, feces is difficult to eliminate |
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Term
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Definition
| fat emulsifier – breaks fat down into little pieces, increase surface area for enzymes to work better |
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Term
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Definition
| largest gland in body, about 3 lbs; Upper right quadrant, under ribs and diaphragm; produces bile |
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Term
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Definition
| divides liver into right and left, suspends liver from diaphragm |
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Term
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Definition
| remains of fetal umbilical vein |
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Term
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Definition
| (hexagonal shaped structures made of groups or plates of liver cells; Plates radiate out from a central vein that runs along the central axis |
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Term
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Definition
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Term
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Definition
| At each of the 6 corners of liver lobule; consist of vein, artery, and a bile duct |
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Term
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Definition
1. Produce bile
2. Produce nutrients (excess glucose to glycogen, amino acids to plasma proteins, etc.)
3. Store fat soluble vitamins
4. Detoxification – ammonia to urea, drugs, etc. |
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Term
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Definition
| Basic; Contains pigments (RBC), bile salts, cholesterol, triglycerides, phospholipids, electrolytes; stored in gallbladder, where it’s concentrated; released through cystic duct, then into duodenum through bile duct |
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Term
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Definition
| Soft, tapered gland that extends across the abdomen, under the stomach, and surrounded by the duodenum; Drains juices through main pancreatic duct and fuses with the bile duct from the gall bladder and dumps into the duodenum |
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Term
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Definition
| a mixture of enzymes to digest all categories of food (Fats, proteins, carbohydrates) |
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Term
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Definition
| Clusters of cells that produce the pancreatic juices |
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Term
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Definition
| produce insulin and glucagon – hormones important in carbohydrate metabolism |
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Term
| Epithelial cells in lining of pancreas |
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Definition
| make bicarbonate ions to neutralize acid |
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Term
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Definition
| released in the inactive form; don’t become active until they mix with basic environment of the duodenum. (example – trypsinogen becomes trypsin to digest protein) |
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Term
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Definition
1. Amylase – digests carbohydrates
2. Lipase – digests fats
3. Nucleases – digest nucleic acids (DNA & RNA |
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Term
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Definition
| process in which large food molecules are broken down into monomers |
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Term
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Definition
| small chemical building blocks that are absorbed by the GI tract |
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Term
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Definition
| involves adding a water molecule to break bonds |
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Term
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Definition
| simple sugars that do not need digested, absorbed directly – glucose, fructose, and galactose |
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Term
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Definition
| “double” sugars – only 2 molecules together that need split or digested – includes sucrose, lactose, and maltose |
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Term
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Definition
| many sugars – includes complex sugars such as starches, glycogen, and cellulose (cellulose is indigestible, “fiber” good at cleaning GI tract) |
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Term
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Definition
| Sugar/starch digestion; begins in the mouth |
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Term
| maltase, sucrose, lactase |
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Definition
| in small intestine; other enzymes for specific sugars |
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Term
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Definition
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Term
| trypsin, chymotrypsin, carboxypeptidase, aminopeptidase and dipeptidase |
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Definition
| secreted by pancreatic cells; in the small intestine; digests proteins not digested in the stomach |
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Term
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Definition
| molecules are covered with hydrogen atoms, tend to be solids at room temperature |
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Term
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Definition
| less hydrogen due to double bonds between atoms, usually liquid at room temperature (healthier for humans) |
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Term
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Definition
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Term
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Definition
| Non-water soluble so must be “pretreated” with bile salts to be emulsified -reduces the attraction between the fat molecules so they become further apart, big drops broken down to many little drops; digested only by the pancreatic lipase |
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Term
| fatty acids, monoglycerides, and glycerol |
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Definition
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Term
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Definition
| the DNA and RNA contained in the nuclei of the cells of the food we eat |
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Term
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Definition
| digests the DNA and RNA to the nucleotide monomers in the small intestine |
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Term
| nucleotidases and phosphatases |
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Definition
| small intestine;breaks down nucleotides to their building blocks |
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Term
| Remains of small intestine that move on to large intestine |
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Definition
| some water, indigestible cellulose and fiber, and millions of bacteria |
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Term
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Definition
| viral infection of the parotid salivary glands, spread through saliva, Can cause high fevers in adult males, a 25% risk of sterility. |
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Term
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Definition
| erosion of stomach wall, where the mucus barrier of the stomach has been compromised, very painful, can lead to perforated bacterial infections. |
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Term
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Definition
| aka emesis – reverse peristalsis where food stuff is forced up esophagus; most often caused by overeating or irritants (bacteria, toxins, etc.) |
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Term
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Definition
| inflammation of the liver, most often due to viral infections, also poisonings, rates of hepatitis have dropped in US due to vaccinations, sanitation, and medication. |
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Term
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Definition
| chronic inflammation of the liver, usually brought on by alcoholism, liver becomes scarred & fatty, stops functioning. |
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Term
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Definition
| when bile salts & cholesterol from liver crystallize and form stones, can block bile duct, usually requires surgery. |
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Term
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Definition
| acute inflammation of the appendix that results from blockage (usually feces) of the opening/lumen, eventually the appendix swells, can rupture or cause tissue death. |
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Term
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Definition
| infection of the peritoneum – serous membrane that covers the abdomen, usually from wounds or ruptured appendix |
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Term
| Inflammatory Bowel Disease |
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Definition
| non-contagious periodic inflammation of the bowel, most often caused by an abnormal immune response to bacteria in intestine, painful, includes diarrhea, bleeding from ulcers, weightloss; 2 types: crohn's disease and colitis |
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Term
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Definition
| deep ulcers and inflammation along length of small intestine but mostly ileum. |
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Term
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Definition
| deep ulcers and inflammation along length of small intestine but mostly ileum. |
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Term
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Definition
| in large intestine, mainly in rectum – both treated with drugs, diet. |
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