Term
| What three nutritional needs must a diet satisfy? |
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Definition
1) fuel for cellular work
2) organic raw materials for biosynthesis
3) essential nutrients that the animal cannot make for itself (vitamins) |
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Term
| Food must be broken down into _______ _________, which is the role of the digestive system. |
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Definition
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Term
| What are the four main stages of food processing? |
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Definition
1) ingestion (eating)
2) digestion
3) absorption
4) elimination |
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Term
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Definition
- eating
- mechanical breakdown of food |
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Term
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Definition
- process of breaking food down into molecules small enough to absorb
- involves enzymatic breakdown of polymers into their monomers |
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Term
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Definition
| uptake of nutrients by body cells |
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Term
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Definition
| exit of undigested material passes from digestive compartment |
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Term
| What is the makeup of the mammalian digestive system? |
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Definition
- the alimentary canal
- accessory glands |
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Term
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Definition
secrete digestive "juices" through ducts
1) salivary glands
2) pancreas
3) liver
4) gall bladder |
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Term
| What are the three features of the digestive tract? |
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Definition
1) peristalsis
2) sphincters
3) accessory glands |
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Term
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Definition
| rhythmic waves of contraction of smooth muscles in the wall of the canal, pushing food along digestive tract |
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Term
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Definition
| ringlike muscles; regulate passage of materials |
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Term
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Definition
| mechanical/chemical digestion begins, teeth chew food into smaller particles; mammals have specialized dentition |
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Term
| In the oral cavity the presence of food stimulates ______ ________. |
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Definition
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Term
| What are the the four components of saliva secretion? What do they do? |
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Definition
1) amylase (initiates breakdown of glucose polymers)
2) mucin (lubrication)
3) buffers (prevents tooth decay)
4) antibacterial agents |
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Term
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Definition
-tasting food
- manipulation of food/shaping into bolus
- pushes bolus to rear of oral cavity to pharynx |
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Term
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Definition
- junction opening to the esophagus and trachea
- epiglottis (flap closes off glottis) |
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Term
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Definition
- conducts food from pharynx to the stomach
- peristalsis pushes food |
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Term
| The stomach is ______ so it can store food up to 2 L. |
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Definition
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Term
| What does the lining of the stomach secrete? What does it do? |
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Definition
| gastric juice; converts food to act chyme, breaks up ECM and kills most bacteria |
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Term
| What is gastric juice made out of? |
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Definition
| hydrochloric acid and enzyme pepsin |
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Term
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Definition
-low pH of juice
- secreted by parietal cells |
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Term
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Definition
| hydrolysis of proteins, breaks peptitde bonds, chief cells secrete inactive form (pepsinogen) and then it is activated by the acid |
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Term
| What is the inactive form of pepsin, secreted by chief cells? |
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Definition
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Term
| The lining of the stomach is coated with ________. What does it prevent? |
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Definition
| mucus; gastric secretions from destroying the cells |
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Term
| What bacterium causes gastric ulcers? |
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Definition
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Term
| What is the longest section of the alimentary canal? |
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Definition
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Term
| What is the major organ of digestion and absorption? |
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Definition
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Term
| What are the three sections of the small intestine? |
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Definition
1) duodenum
2) jejunum
3) ileum |
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Term
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Definition
- first portion of the small intestine
- acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and intestine itself |
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Term
| What are the major functions of the liver? |
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Definition
| detox, glucose regulation, digestion |
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Term
| What role does the liver play in digestion? |
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Definition
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Term
| What does the bile of the liver contain? What does it aid in? Where is it stored? |
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Definition
| bile salt; aids in fat digestion; gall bladder |
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Term
| What two things does the pancreas produce? |
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Definition
1) hydrolytic enzymes (proteases)
2) insulin |
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Term
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Definition
| produced in the pancreas; hydrolytic enzymes; secreted as inactive precursors |
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Term
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Definition
| produced by the pancreas; absorption of sugar from bloodstream |
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Term
| _________ help coordinate the secretion of digestive juices into the alimentary canal. |
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Definition
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Term
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Definition
| hormone in the small intestine; AAs and fatty acids trigger it to be released; stimulates the release of digestive enzymes from the pancreas and bile from the gallbladder |
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Term
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Definition
| hormone of the small intestine; stimulates the pancreas to release sodium bicarbonate, which neutralizes acid chyme from the stomach |
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Term
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Definition
| hormone from the stomach, recircualtes via the bloodstream back to the stomach, where it stimulates the production of gastric juices |
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Term
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Definition
| hormone secreted by the small intestine, inhibits peristalsis and acid secretion by the stomach, slowing digestion when acid chyme rich in fats enter the small intestine |
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Term
| What two aspects cause the small intestines to have such a huge absorptive surface area? |
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Definition
| villi and microvilli (exposed to the intestinal lumen) |
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Term
| What does the huge absorptive surface area of the small intestine greatly increase? |
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Definition
| the rate of nutrient absorption |
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Term
| What is at the core of each villus? |
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Definition
| network of blood vessels and a small vessel of the lymphatic system (lacteal) |
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Term
| Amino acids and sugars pass through the _________ of the small intestine and enter the ___________. |
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Definition
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Term
| Glycerol and fatty acids are absorbed by _________ ______ and recombined into fats within these cells. |
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Definition
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Term
| Fats absorbed by epithelial cells in the small intestine are mixed with ______ and coated with _________. What are they called when they are formed? |
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Definition
| cholesterol; protein; chylomicrons |
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Term
| Chylomicrons are formed and transported into ________. |
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Definition
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Term
Where are each of these digested?
a) carbohydrates
b) protein
c) nucleic acid
d) fat |
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Definition
a) oral cavity & small intestine
b) stomach and small intestine
c) small intestine
d) small intestine |
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Term
| What is the major function of the large intestine (colon)? |
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Definition
| recover water that has entered the alimentary canal |
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Term
Where are each of these digested?
a) carbohydrates
b) protein
c) nucleic acid
d) fat |
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Definition
a) oral cavity & small intestine
b) stomach and small intestine
c) small intestine
d) small intestine |
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Term
| What is the major function of the large intestine (colon)? |
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Definition
| recover water that has entered the alimentary canal |
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Term
| What strains of bacterium does the large intestine house? |
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Definition
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Term
| Digestive waste (feces) becomes more ______ as it moves through the colon. |
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Definition
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Term
| How long does it take for a bowel movement to occur? |
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Definition
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Term
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Definition
| bacteria and undigested material (e.g. cellulose) |
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Term
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Definition
| terminal portion of colon; stores feces until defecation |
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Term
| What is nearly all of an animal's ATP generation based on? |
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Definition
| the oxidation of energy-rich molecules (carbs, proteins, fats) |
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Term
| If more calories taken in than expanded then __________ can occur. |
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Definition
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Term
| What is the major fuel for cells? |
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Definition
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Term
| Metabolism is regulated by ________ ______. |
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Definition
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Term
| What is hormone action an important example of? |
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Definition
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Term
| Where are excess calories stored? What are they stored as? |
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Definition
| liver and muscles; glycogen and fat |
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Term
| What hormone is involved with weight control? |
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Definition
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Term
| Leptin is _____ in obese humans. |
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Definition
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