Term
| What is the Digestive System- |
|
Definition
| Collection of organs that work together to take consumed nutrients too large to directly enter into the blood and transfer them to the body's internal environment. |
|
|
Term
| What does the Digestive System include: |
|
Definition
| Mouth, salivary glands, esophagus, stomach, small and large intestive (colon), pancreas, and liver. |
|
|
Term
| What are the four major digestive processes? |
|
Definition
Motility
Secretion
Digestion
Absorption |
|
|
Term
|
Definition
Contractions of smooth muscle in the walls of the digestive tract.
-Propulsive and Mixing Movements. |
|
|
Term
| Which Nervous system (and other) is motility controlled by? |
|
Definition
| Autonomic Nervous System and hormones. |
|
|
Term
| What are propulsive movements? |
|
Definition
| Peristalsis- move contents forward through digestive tract. |
|
|
Term
| What is Segmentation/ Mixing movements? |
|
Definition
| mixing of food with digestive enzyme, acid in stomach, and also exposing nutrients to absorbing surface of intestine. |
|
|
Term
| How is the smooth muscle in the small intestine layered? |
|
Definition
| Two layers- longitudinal and circular |
|
|
Term
| What does Peristalsis Require? |
|
Definition
| Coordination of circular and longitudinal muscle contractions in segments of intestine. |
|
|
Term
|
Definition
| Contents propelled forward from small diameter to large. |
|
|
Term
| During Peristalsis the Proximal Segment: |
|
Definition
| Circular muscle contracts, longitudinal relaxes- pushed contents along b/c diameter decreases. |
|
|
Term
| During Peristalsis the Distal Segment: |
|
Definition
| Circular muscle relaxes, longitudinal muscle contracts. The diameter increases which receives content. |
|
|
Term
Segmentation is-
Requires- |
|
Definition
| alternating contractions between intestinal segments that mixes contents of digestive tract. Requires circular muscle layer. |
|
|
Term
| When does Migrating Motility Complex (MMC) occur? |
|
Definition
|
|
Term
| What is Migrating Motility Complex? |
|
Definition
| Intense Contractions that travel from stomach to large intestine. |
|
|
Term
| How is migrating motility complex different from a typical peristaltic wave? |
|
Definition
| Peristaltic waves usually fade away after a short distance. |
|
|
Term
| What do migrating motility complexes do? |
|
Definition
| Sweep clean the small and large intestines in preparation of next meal. |
|
|
Term
|
Definition
| Movement of substances into digestive tract lumen. |
|
|
Term
|
Definition
Digestive enzymes
Gastric acid
Bile salts
Hormones
water |
|
|
Term
| What do digestive enzymes do- |
|
Definition
| chemically breakdown nutrients |
|
|
Term
|
Definition
| aid in digestion of fats. |
|
|
Term
| amount of fluid excreted in feces |
|
Definition
|
|
Term
|
Definition
| Biochemically breakdown by digestive enzymes of nutrients (Carbohydrates, fats, proteins) into smaller absorbable units, (monosaccharides, fatty acids, amino acids) |
|
|
Term
|
Definition
| Small absorbable units are transferred from digestive tract into blood or lymph. |
|
|
Term
| Where does most absorption occur? |
|
Definition
|
|
Term
| What are Salivary Glands? |
|
Definition
Three paired glands in oral cavity.
1. Parotid,
2. Sublingual
3. Submandibular |
|
|
Term
|
Definition
| Moistens and lubricates food so its easier to swallow. |
|
|
Term
| What enzyme do salivary glands secrete? & what does it do? |
|
Definition
Salivary amylase- breaks down starch into maltose (2 glucose molecules).
Starts some carbohydrate digestion in mouth. |
|
|
Term
| What is the Saliva Secretion-reflex? |
|
Definition
taste and texture of food-
Mechanoreceptors and taste receptors in mouth- Salivary Center of medulla-
autonomic nervous system-
stimulate salivation |
|
|
Term
| Which Nervous System controls Salivary Glands? |
|
Definition
| Autonomic/ Parasympathetics and Sympathetic |
|
|
Term
| How input does the parasympathetic system have on salivary glands? |
|
Definition
| Increases the watery-ness of saliva. |
|
|
Term
| Sympathetic input on salivary glands- |
|
Definition
| Increases mucus, thick-ness of saliva. |
|
|
Term
| Which division of the autonomic nervous system increases saliva secretion? |
|
Definition
| Both parasympathetic and Sympathetic |
|
|
Term
| How many regions is the stomach divided in functionally and anatomically? |
|
Definition
|
|
Term
|
Definition
| Stores food after swallowed, secretes gastric juice, releases food into intestine slowly. |
|
|
Term
| Empty volume of the stomach- |
|
Definition
|
|
Term
| Full volume of the stomach- |
|
Definition
|
|
Term
| Three divisions of the stomach are- |
|
Definition
|
|
Term
|
Definition
| Spincters (thick bands of smooth muscle) |
|
|
Term
| How does the stomach accomodate food as swallowed? |
|
Definition
|
|
Term
| What allows the stomach to expand? |
|
Definition
|
|
Term
|
Definition
| Folds that flatten on expansion |
|
|
Term
| Where are nemerous cell-lines gastric pits? |
|
Definition
|
|
Term
How many different cell types are in the body of the stomach's pits?
Names? |
|
Definition
2:
Parietal And Chief Cells |
|
|
Term
| What do parietal cells do? |
|
Definition
| secrete hydrocholoric acid (HCL, gastric acid) and intrinsic factor |
|
|
Term
| What can pH reach in the stomach? |
|
Definition
|
|
Term
| What does gastric acid do? |
|
Definition
| breaks down connective tissue and cells to release content and kill bacteria. |
|
|
Term
| Does gastric acid biochemically breakdown nutrients? |
|
Definition
| No, there is no digestion. |
|
|
Term
| Is it possible to survive without gastric acid? |
|
Definition
|
|
Term
|
Definition
| Thick, semi-solid mixture produced by parietal cells |
|
|
Term
| What is intrinsic factor? |
|
Definition
| A molecule needed for the absorption of vitamin B12 in small intestine. |
|
|
Term
| What stops the acidic environment of the stomach from damaging the stomach cells? |
|
Definition
|
|
Term
| What is the Gastric mucosal barrier? |
|
Definition
| Protective layer of mucus and bicarbonate |
|
|
Term
| What increases protective layer of the stomach? |
|
Definition
|
|
Term
| What does aspirin do in regards of the stomach? |
|
Definition
| Inhibits prostaglandins leading to acid damage and ulcers. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| precursor to pepsin, activated by HCL and active pepsin. |
|
|
Term
| Where does protein digestion start? By what? |
|
Definition
|
|
Term
|
Definition
| gastric pits contain G cells that secrete gastrin |
|
|
Term
| Parietal cells produce acid by using what enzyme to join H+ and Cl-: |
|
Definition
|
|
Term
| Type of transport of H+ into the stomach: |
|
Definition
| Active Transport, H+ into lumen in exchange for K+ |
|
|
Term
| Bicarbonate is transported into -- for exchange of --. |
|
Definition
| Interstitial fluid in exchange for Chloride |
|
|
Term
| How does chloride get into lumen? |
|
Definition
|
|
Term
| H+ and Cl- in the lumen = |
|
Definition
| formation of HCL (gastric acid |
|
|
Term
| How do many acid reducing drugs work? |
|
Definition
|
|
Term
| What stimulates acid secretion? |
|
Definition
Parasympathetic Nervous System- acetylcholine.
Hormone- Gastrin
Paracrine (in cells of stomach) - Histamine. |
|
|
Term
How many phases regulate gastric acid secretion?
Names- |
|
Definition
3
Cephalic-Phase
Gastric-Phase
Intestinal-Phase |
|
|
Term
| What occurs in cephalic-phase? |
|
Definition
increased acid and pepsinogen secretion
-sight of food, taste, smell, chewing, swallowing.
Parasympathetic Nervous system is fully activated and stimulates gastrin secretion |
|
|
Term
| What occurs in Gastric-Phase Regulation? |
|
Definition
reflex pathways trigger gastrin, acid, and pepsinogen
Secretion is stimulated by proteins, peptides, amino acids, distension of stomach. |
|
|
Term
| How does the gastric phase inhibit secretion? |
|
Definition
| exit of food removes stimuli, increased acidity inhibits gastrin release |
|
|
Term
| What occurs in the intestinal phase? |
|
Definition
| the entry of chyme into small instestine causes increased acidity of contents and increased amounts of fat which signal the secretion of cholecytokinin (CCK) which inhints gastric acid scretion in stomach. |
|
|
Term
| What is the small intestine? |
|
Definition
| Coiled hollow tube in 3 division where the primary site of digestion and absorption takes place. |
|
|
Term
| How long is the small intestine? Where is it located? |
|
Definition
8-10 ft
Between stomach and large intestine. |
|
|
Term
| What are the 3 divisions of the small intestine? |
|
Definition
|
|
Term
| What enters the duodenum? |
|
Definition
| Pancreatic juice and bile |
|
|
Term
|
Definition
| Bicarbonate (neutralizes acidic chyme) and has digestive enzymes. |
|
|
Term
Bile contains
is secreted from
and stored in- |
|
Definition
containes bile salts which aid fat digestion,
secreted from live
and stored in gall bladder |
|
|
Term
| Within what percentage of length is absorption completed from in the small intestine? |
|
Definition
|
|
Term
| The Small intestine is anatomically arranged in what way? |
|
Definition
| For large surface area for absorption |
|
|
Term
| What creates the large surface area of the small intestine? |
|
Definition
| Villi (villus): inner layer folded into microscopic finger-like projections. |
|
|
Term
| Villi increase surface are of-- which contains- |
|
Definition
Epithelium
Blood vessels and lacteal for absorptiono of nutrients. |
|
|
Term
| Epithelial cells in crypts secrete: |
|
Definition
| Bicarbonate-rich fluid and seceral hormones |
|
|
Term
| Microvilli increase and form: |
|
Definition
| surface area of epithelial cells forming brush border. |
|
|
Term
| Digestion in small intestine depends on? |
|
Definition
| Digestive enzymes primarily from pancreas |
|
|
Term
| Types of pancreatic enzymes? |
|
Definition
Pancreatic amylase
Trypsin, chymotrypsin
Pancreatic Lipase |
|
|
Term
| Pancreatic amylase digests: |
|
Definition
| Starch into maltose (disaccharide) |
|
|
Term
| Trypsin, chymotrypsin digests: |
|
Definition
| Proteins into amino acids and small peptides |
|
|
Term
| Pancreatic Lipase digests: |
|
Definition
| Fat into monoglycerides and fatty acids |
|
|
Term
| Most carbs are consumed as: |
|
Definition
| disaccharides (2 monosacchrides) or polysaccharides (long chains of monosaccharides like glucose) |
|
|
Term
Sucrose=
Lactose=
Maltose=
Starch=
Glycogen=
Cellulose= |
|
Definition
glucose+fructose
glucose+galactose
glucose+glucose
Storage in plants
storage in animals
fiber, not digested |
|
|
Term
| What type of carbs can be absorbed? |
|
Definition
| Only monosaccharide, disaccharide sand polysaccharides must be digested down to monosaccharides |
|
|
Term
which enzymes digest starch>
resulting in- |
|
Definition
salivary or pancreatic amylase
end products= disaccharides (maltose) and limit dextrins |
|
|
Term
| Intestinal epithelial cells have membrane bound - |
|
Definition
enzymes
plasma membrane of small intestine. |
|
|
Term
| plasma membrane of small intestine is the location of which enzymes? |
|
Definition
brush border enzyme
maltase
sucrase
lactase |
|
|
Term
|
Definition
| transport from lumen to blood. |
|
|
Term
| How are glucose and galactose absorbed? |
|
Definition
secondary active trasport across apical membrane, Co-transported with Na+
Facillitaed diffusion across basolateral membrane |
|
|
Term
| how is fructose absorbed? |
|
Definition
| facillated diffusion across both membranes |
|
|
Term
|
Definition
| enzymes that digest proteins |
|
|
Term
| Digestion products of proteins include: |
|
Definition
| amino acids, dipeptides, tripeptides |
|
|
Term
| How are proteases secreted? |
|
Definition
| From the pancreas in an inactive form. |
|
|
Term
| Where are proteases activated? |
|
Definition
| inside lumen of small intestine |
|
|
Term
| What secreates trypsinogen, what activates it? |
|
Definition
| Pancreas. Enterokinase in small intestine. |
|
|
Term
| What does activated trypsin do? |
|
Definition
| It can activate chymotrypsin and other proteases. |
|
|
Term
| How are amino acids absorbed? |
|
Definition
| cross apical membrane by sodium linked secondary active transport or facilitated diffusion |
|
|
Term
| Are there different transporters for different amnino acids? |
|
Definition
|
|
Term
| How do amino acids cross basolateral membrane? |
|
Definition
|
|
Term
| How do dipeptides and tripeptides cross apical membrane? How do amino acids? |
|
Definition
By active transport.
Amino acids cross by facillitate diffusion |
|
|
Term
| Can small peptides be absorbed into blood? |
|
Definition
| Yes, might cause food allergies |
|
|
Term
| What percentages of lipids ingested are triglycerides. |
|
Definition
|
|
Term
| What problems do lipids face in digestion? |
|
Definition
Not water soluble
don't mix with stomach and intestinal contents
form fat droplets |
|
|
Term
What enzyme digest lipids?
Where are they secreted? |
|
Definition
|
|
Term
|
Definition
| Break triglycerides into a monoglyceride and 2 fatty acids |
|
|
Term
| Where can lipases act on triglycerides? |
|
Definition
| Only nerar edge of fat droplet |
|
|
Term
| are some fatty acids and monoglycerides absorbed immediately? |
|
Definition
|
|
Term
|
Definition
| The sheilding of non-polar parts from water allowing the fatty acid/monoglycerides to remain in solution. The polar parts face outward |
|
|
Term
| What does the mixing action of intestines do to micelles? |
|
Definition
| Brings them close to epithelial cells allowing the monoglycerides and fatty acids to leave the micelle and be absorbed |
|
|
Term
| how are monoglycerides and fatty acids absorbed? |
|
Definition
| simple diffusion because they are lipid soluble |
|
|
Term
| monoglycerides and fatty acids inside epithelial cell enter-- and reform-- which- |
|
Definition
| smooth ER reform triglycerides which enter Golgi apparatus to be packaged into chylomicrons |
|
|
Term
|
Definition
triglyceride+proteins+cholestrol
They are extruded from cell into Interstitial fluid and enter lymphatic system via lacteals. |
|
|
Term
| Why do chylomicrons enter lacteals? |
|
Definition
| too large to enter blood capillaries directly and eventually enter into blood from lymphatics |
|
|
Term
| Where do chylomicron travel? |
|
Definition
|
|
Term
| What is lipoprotein lipase? |
|
Definition
| an enzyme in tissue capillaries that splits off fatty acids and monoglyceries to enter into cells for energy |
|
|
Term
| What happens to leftover chylomicrons? |
|
Definition
they are taken up by liver and metabolized.
Some fatty acids are incorporated into lipoproteins (droplets of fatty acids and cholesterol coated proteins) and resecreated into blood. |
|
|
Term
|
Definition
Low density lipoproteins= high cholesterol to protein ration.
Bad cholesterol
associated with cardiovascular disease |
|
|
Term
|
Definition
High density lipoproteins- high protein to cholesterol ration
Good cholesterol |
|
|
Term
|
Definition
| hollow tube from small intestine to rectum |
|
|
Term
|
Definition
concentrates wastes into feces
absorption of most remaining water that wasn't by small intestine (about 400 mL)
Water follows absorption of solutes by osmosis
Stores feces until defecation |
|
|
Term
|
Definition
| exocrine and endocrine gland |
|
|
Term
| Pancreatic juice is made up of and is dumped into the duodenum via |
|
Definition
-Bicarbonate, pancratic amylase, pancreatic lipases, proteases
-Pancreatic Duct |
|
|
Term
| What other hormones does the pancreas secrete? |
|
Definition
| hormones involved with nutrient regulation |
|
|
Term
| What controls pancreas secretion? |
|
Definition
2 major hormons
-Cholecystokinin (CCK)
-Secretin |
|
|
Term
|
Definition
stimulates digestive enzyme secretion by pancreatic cells from endocrine cells in small intestine in response to fats and amino acids entering duodenum
-Travels to pancreas by blood |
|
|
Term
|
Definition
stimulates pancreas to secrete a fluid with a high bicarbonate concentration
Released from small intestine in response to acid
Bicarbonates enters duodenum and neutralizes any acid entering from stomach |
|
|
Term
| What is control of nutrient balance? |
|
Definition
| absorptive and post-absorptive states of nutrient balance |
|
|
Term
| Is nutrient intake into body continuous? |
|
Definition
|
|
Term
| When is absorptive state? |
|
Definition
| 3-4 hours following a meal |
|
|
Term
| Nutrients in bloodstream are plentiful during |
|
Definition
|
|
Term
| When is post-absorptive state? |
|
Definition
|
|
Term
| When do nutrient stores need to be mobilized to be used for energy? |
|
Definition
| during post-absorption state |
|
|
Term
| When are nutrients in excess? What solves this? |
|
Definition
During absorptive state
Storage for later use |
|
|
Term
|
Definition
|
|
Term
| How are monogylcerides/fatty acids stored? |
|
Definition
|
|
Term
| how are amino acids stored? |
|
Definition
|
|
Term
| Where are nutrients mostly stored? |
|
Definition
| liver, adipose (fat cells) and skeletal cells |
|
|
Term
| how much glycogen is stored in liver and muscle? how long does that last? |
|
Definition
| 500 g. enough for only a few hours |
|
|
Term
| how much triglceride storage is in adipose tissue? |
|
Definition
| abundant (some also in liver) |
|
|
Term
| Which nutrient is last to be mobilized? |
|
Definition
|
|
Term
| what primarily regulates nutrient balance? |
|
Definition
| hormones secreted by endocrine cells in pancreas |
|
|
Term
What are islets of langerhans?
How many types?
What do they do? |
|
Definition
cluseters of endocrine cells.
-4 types
Alpha secrete glucagon
beta secret insulin |
|
|
Term
| What is the primary energy source for cells? |
|
Definition
|
|
Term
| What is the primary hormone of absorptive state? |
|
Definition
|
|
Term
| What disease is when a body's own immune system destroys beta cells so no or little insulin is secreted? |
|
Definition
|
|
Term
| What disease is when body cells do not respond properly to insulin |
|
Definition
|
|
Term
|
Definition
promotes synthesis of nutrient storage molecules (anabolic reactions)
Promotes glucose use for energy |
|
|
Term
liver and muscle store:
adipose tissue stores: |
|
Definition
|
|
Term
| insulin (increases or decreases) glucose uptake by most body cells? |
|
Definition
|
|
Term
| Increases in number of glucose transporters inserted into plasma membrane is due to |
|
Definition
|
|
Term
| Primary stimulus for insulin secretion- |
|
Definition
| increased glucose in plasma |
|
|
Term
| What state is insulin secretion increased? |
|
Definition
|
|
Term
| What else increases secretion of insulin? |
|
Definition
| increased amino acids in plasma and parasympthetic nervous system |
|
|
Term
| What state is insulin secretion decreased? |
|
Definition
|
|
Term
| What factors decrease insulin secretion? |
|
Definition
sympathetic nervous activity
epinephrine |
|
|
Term
| What state is nutrient input > output |
|
Definition
|
|
Term
| What state is nutrient input < output |
|
Definition
|
|
Term
| What is the primary hormone of post absorptive state? |
|
Definition
|
|
Term
|
Definition
stored nutrients are broke down and mobilized
glycogen-> glucose
triglycerides-> fatty acids
proteins _> amino acids |
|
|
Term
| What is glucose spared for? Meaning other tissues use primarily- for sources of energy |
|
Definition
Brain (nervous sys)
fatty acids |
|
|
Term
| what is the primary stimulus for glucagon secretion increased? |
|
Definition
| decreased blood glucose levels |
|
|
Term
| What are other stimulus's for glucagon secretion |
|
Definition
sympathetic nervous system
epinephrine |
|
|
Term
| When is there a decrease in glucagon secretion? |
|
Definition
| increased glucose in plasma |
|
|
Term
|
Definition
mobilization of energy stores, synthesize new glucose
Equalling a net result of incread glucose and fatty acids released into blood for energy uses |
|
|
Term
| How does glucagon mobilize energy stores? |
|
Definition
-Glycogenolysis- breakdown of glycogen into glycose
-Lipolysis- breakdown of triglycerides |
|
|
Term
| How doe glucagon synthesize new glucose? |
|
Definition
| gluconeogenesis- liver have enzymes that make new glucose from amino acids, pyruvic acid, lactic acid, and glycerol |
|
|
Term
|
Definition
produced during metabolism of fatty acids in liver.
Include acetone, acetylacteone, acetoacetic |
|
|
Term
| When are ketones increased? |
|
Definition
|
|
Term
|
Definition
many tissues for energy
-70% of energy used in heart comes from ketones.
-Nervous system can use ketones during starvation |
|
|
Term
| Uncontrolled diabetes mellitus increases |
|
Definition
| ketone production producing diabetic ketoacidosis=coma |
|
|
