digestion, metabolism, reproductive system
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| 4 basic processes of digestion | motility, secretion, digestion, absorption
🗑
|
||||
| motility | movement of material through the GI tract/alimentary canal; aka mechanical digestion
🗑
|
||||
| secretion | happens throughout digestion when organs secrete different hormones, paracrines, etc.
🗑
|
||||
| digestion | breaking bonds; enzymatic process that breaks lipids, proteins and carbohydrates into smaller parts
🗑
|
||||
| absorption | takes place almost completely in the small intestine, where nutrients enter the bloodstream
🗑
|
||||
| saliva | 99.5% water, also contains electrolytes and protein
🗑
|
||||
| functions of saliva | moistening and lubricating food, antibacterial actions, solvent for tastants, aids speech
🗑
|
||||
| amount of saliva produced each day | 1-2 L, continuous flow of .5 mL/min due to tonic parasympathetic activation
🗑
|
||||
| simple salivary reflex | chemoreceptors and pressure sensors respond to food; salivary center is located in the medulla
🗑
|
||||
| conditioned salivary reflex | salivary center is activated by thinking, seeing, smelling and/or hearing food
🗑
|
||||
| oral cavity function during digestion | secretion (saliva, amylase), motility (moves food to the esophagus for transport to the stomach, intestines)
🗑
|
||||
| amylase | enzyme that begins carbohydrate digestion - breaks them into disaccharides; improves taste and begins chemical digestion
🗑
|
||||
| factors that affect gastric emptying | 1. duodenal fat, acid, hypertonicity, and distention (usually these are inhibitory)
2. amount of chyme in the stomach
🗑
|
||||
| vomiting | controlled by vomit center in the medulla; begins with deep inhalation and closure of the glottis; relaxation of stomach and esphagus, contraction of diaphragm and abdominals
🗑
|
||||
| functions of the stomach during digestion | motility (regulates movement of material into the small intestine), secretion (HCl, gastrin, mucus, pepsinogen, intrinsic factor)
🗑
|
||||
| gastrin | hormone that stimulates secretion of HCl
🗑
|
||||
| amount of secretions from the stomach each day | 2 L/day
🗑
|
||||
| stomach - cells that secrete | mucus cells - mucus, chief cells - pepsinogen, parietal cells - HCl and intrinsic factor
🗑
|
||||
| function of HCl | activates pepsinogen, optimizes pepsin activity; aids in connective tissue breakdown; denatures proteins; kills most microorganisms
🗑
|
||||
| pH of the stomach | 1-2
🗑
|
||||
| intrinsic factor | binds to B12, required for absorption of B12 in the small intestine
🗑
|
||||
| pepsinogen | precursor enzyme that becomes actives when exposed to pH of 2.
🗑
|
||||
| protease | begins breakdown of proteins into smaller peptide chains
🗑
|
||||
| hormones/neurotransmitters that influence parietal and chief cell activity in the stomach | acetylcholine, gastrin, histamine, somatostatin
🗑
|
||||
| 3 phases of digestion | cephalic (stimulated by food), gastric (stimulated by internal environment of the stomach), intestinal (stimulated by the small intestine)
🗑
|
||||
| histamine | paracrine that stimulates secretion
🗑
|
||||
| somatostatin | inhibitory hormone; suppresses, slows down digestive activity
🗑
|
||||
| absorption in the stomach | alcohol (slow) and aspirin are absorbed, no food is absorbed here
🗑
|
||||
| pancreatic secretions | exocrine (pancreatic juice) and endocrine (insulin); regulated during the intestinal phase of digestion
🗑
|
||||
| pancreatic lipase | breaks down lipids, only source is the pancreas
🗑
|
||||
| acinar cells | produce pancreatic enzymes (proteolytic enzyme, pancreatic amylase, pancreatic lipase)
🗑
|
||||
| duct cells | produce aqueous alkaline solution (mucus) that is bicarbonate-rich
🗑
|
||||
| secretin | hormone released by the pancreas in response to acid
🗑
|
||||
| cholecystokinin (CCK) | released by the pancreas in response to fat
🗑
|
||||
| 3 sources of bicarbonate that will raise the PH of the digestive tract | duodenum, pancreas, liver (bile)
🗑
|
||||
| liver secretions | bile - bile salts, cholesterol, bilirubin, aqueous alkaline fluid
🗑
|
||||
| bilirubin | waste product from breakdown of red blood cells; turns feces green and urine yellow
🗑
|
||||
| bile salts | required for fat digestion; emulsify fats; are "recycled" via enterohepatic circulation; need 15 g after a big meal, usually only 3-4 g of bile salts are out at a time
🗑
|
||||
| segmentation | occurs during a meal; mixes and slowly propels; controlled by intestinal pacemaker cells
🗑
|
||||
| migrating motility complex | intestinal housekeeper; weak persistent waves that move what is left in the intestines right along; contractions break down food, increasing surface area (segmantation); prevents backup of microorganisms
🗑
|
||||
| small intestine secretion | succus entericus, digestive enzymes (enterokinase, disaccharidases, aminopeptidases)
🗑
|
||||
| succus entericus | aqueous salt/mucus solution that lubricates and protects the small intestine; contains water needed for hydrolytic digestive reactions, does not include enzymes; about 1/5 L /day secreted
🗑
|
||||
| enterokinase | activates pancreatic trypsin, breaks down peptides into individual amino acids
🗑
|
||||
| disaccharidases | sucrase, maltase, lactase
🗑
|
||||
| 3 anatomical features that greatly increase surface area of small intestine | folds, villi, microvilli
🗑
|
||||
| energy dependent Na+ absorption in the small intestine | apical - symport with Cl-, glucose or amino acid; antiport with H; basal - Na/K pump (requires ATP), located in lateral space creates high osmolarity which drives water absorption
🗑
|
||||
| carbohydrate and protein absorption in the small intestine | apical - occurs via Na+ dependent symport; basal - facilitated diffusion
🗑
|
||||
| fat digestion and absorption in the small intestine | large triglycerides are emulsified by bile salts; pancreatic lipase hydrolyzes triglycerides into monoglycerides and free fatty acids; form micelles; monoglycerides/fatty acids cross apical membrane; form chylomicrons; exocytosis -> central lacteals
🗑
|
||||
| micelles | monoglycerides and free fatty acids that combine with bile salts to aid in transport across apical membrane of the small intestine
🗑
|
||||
| chylomicrons | resynthesized triglycerides coated with lipoproteins for transport across basal membrane via exocytosis
🗑
|
||||
| central lacteal role in fat digestion | carries fats that are too large for the bloodstream
🗑
|
||||
| large intestine functions | motility, secretion, digestion, absorption
🗑
|
||||
| small intestine functions | motility, secretion, digestion, absorption
🗑
|
||||
| haustra | pouches in the large intestine that contract slowly and nonpropulsively; aid in water and electrolyte absorption
🗑
|
||||
| mass movement | occur 3-4 times per day, large portions of ascending/transverse colon contract, driving feces 1/3 to 3/4 the length of the colon over several seconds; controlled by the gastrocolic reflex (stimulated when gastrin is released when food enters the stomach)
🗑
|
||||
| large intestine secretions | entirely protective, alkaline mucus only, no digestive enzymes; lubricates and aids in passage of material
🗑
|
||||
| large intestine digestion | occurs by 500-1,000 different species of resident bacteria, vitamin K and glucose from cellulose are digested
🗑
|
||||
| vitamin K | necessary for the liver to produce certain plasma proteins
🗑
|
||||
| large intestine absorption | active transport of Na+, passive transport of Cl- and water follows osmotically
🗑
|
||||
| feces | 150 g per day; 100 g is water and 50 g is solid; of the solid feces, 1/3 is bacteria, 2/3 is undigestible substances
🗑
|
||||
| gastrointestinal hormones | gastrin, secretin, CCK, GIP
🗑
|
||||
| gastrin | released by the stomach when food is present; increases secretion of HCl and pepsinogen; enhances gastric motility, ileal motility, relaxes ileocecal junction, stimulates mass movements
🗑
|
||||
| secretin | activated by decrease in pH of small intestine; inhibits gastric emptying and secretion; stimulates pancreas and liver to secrete NaHCO3
🗑
|
||||
| cholecystokinin (CCK) | stimulated by fat presence in small intestine; inhibits gastric motility and secretion; stimulates pancreatic enzyme secretion; activates contraction of the gall bladder, relaxation of sphincter of Oddi
🗑
|
||||
| sphincter of Oddi | where bile and pancreatic secretions enter the small intestine
🗑
|
||||
| Gastric Inhibitory Peptide (GIP) | glucose-dependent insulinotrophic peptide; stimulated by the presence of carbs in the small intestine, acts as a feedforward activator of insulin secretion
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
pinklrt98
Popular Physiology sets