Chapter 23: Interactive Physiology: Digestive System
Digestive System: Orientation
1. Absorption is the movement of nutrients and water across the GI epithelium into the blood or ___________________.
Digestive System: Orientation
2. The inner lining of the mucosa is lined with simple _______________________ epithelial cells.
3. Smooth muscle in the muscularis externa produce peristalsis and ________________________________.
4. The enteric nervous system is comprised of the submucosal plexus and the ________________________ plexus.
5. The esophagus conveys a _______________________ to the stomach and enters at the cardia region. .
6. Most digestion and absorption occurs in the _______________________________________.
7. List the 3 regions of the small intestine. ____________________________, ______________________________ ,
and ______________________________________
8. The shortest small intestine region is the __________________________ and the longest is the _______________.
9. The function of the plicae circularis is to increase ______________________________________.
10. The microvilli on the columnar cells of villi form the ______________________________ border.
11. The smooth muscle bands of the large intestine are called _____________________________________.
12. The __________________________ sphincter prevents the reflux of gastric contents into the esophagus.
13. The _________________________valve prevents reflux from the large intestines into the small intestines.
14. The _________________________sphincter controls the rate of gastric emptying into the duodenum.
15. The ____________________ anal sphincter is comprised of skeletal muscle and must be relaxed to defecate.
16. Bile is produced by the _______________ is stored in the ___________________ and is necessary for fat digestion.
Digestive System: Control of the Digestive System
1. Sight, smell and thoughts of food trigger salivation and gastric secretions during the ___________________ phase.
2. Parasympathetic impulses ___________________ digestion and sympathetic impulses _______________ digestion.
3. Intrinsic reflexes which connect different areas of the GI tract are called ________________________ reflexes.
4. The neurotransmitter of the postganglionic fibers of parasympathetic fibers is ____________________________.
5. The neurotransmitter of the postganglionic fibers of sympathetic fibers is ______________________________.
6. Gastrin is secreted from the pyloric region of the stomach and stimulates ___________________ secretion.
7. CCK is secreted from the __________________________ and causes the _____________________ to contract and
the pancreas to secrete enzymes.
8. Secretin is released from the duodenum and causes the liver and pancreas to secrete _________ into the duodenum.
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Digestive System: Motility
1.
The function of chewing is the ________________________breakdown of food and to mix the food with saliva.
2. The esophagus is a conduit between the ____________________________ and the stomach.
3. A typical swallow of a bolus takes ____________________ to reach the stomach by peristalsis.
4. The stomach can stretch to accommodate a large meal by ____________________________ relaxation.
5. Food is mixed and moved out of the stomach by _______________________________________.
6. During the intestinal phase, fat in the duodenum triggers the release of the hormone ______________________.
7. Acid in the duodenum triggers the release of the hormone _______________________________.
8. The motility of the small intestine during digestion is _________________ which mixes the chyme and brings it in
contact with the absorptive epithelium.
9. The major function of the large intestine is in storing and concentrating ________________________________.
10. During the defecation reflex the rectum contracts and the ___________________anal sphincter relaxes involuntarily.
Digestive System: Secretion
1. The total amount of fluid entering the digestive tract in a given day is _____________________ liters.
2. In a given day you produce 1 and ½ liters of saliva and ________________ liters of gastric juice.
3. Saliva contains lysozyme and _______________________ which are antimicrobial.
4. Saliva contains the enzyme __________________________ which begins the digestion of carbohydrates.
5. ____________________ stimulation of salivary glands produces large amounts of watery saliva containing enzymes.
6. In the gastric glands, parietal cells secrete _________________________ and ____________________________.
7. Chief cells secrete ___________________________ which gets activated to the protease ____________________.
8. _________________ secreted from the gastric glands protects the stomach lining from the HCl.
9. Chyme in the stomach is nearly sterile due to the ________________________________.
10. HCl activates _______________________ to pepsin which digest proteins.
11. Pancreatic juice enters the duodenum through the ___________________________ sphincter.
12. The liver and pancreas both secrete __________________________ into the duodenum which helps to neutralize the
acidic chyme from the stomach.
13. The enterohepatic circulation involves the circuit of __________________ from liver to small intestines to blood to
hepatic portal vein back to the liver.
Digestive System: Digestion and Absorption
1. The most abundant dietary carbohydrates are 3 disaccharides and ___________________________.
2. Sucrose is digested to ___________________and fructose. Lactose is digested to _______________ and galactose.
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3. Proteins are digested to ______________________________ and peptides.
4. Protein digestion begins in the ____________________________________ with pepsin.
5. Indigestible fibers contained in fruit and vegetables make up dietary ____________________________.
6. Most of the water and salt that enter the GI tract are absorbed in the ______________________________.
7. The last stage of carbohydrate digestion is to break them down by ________________________enzymes into
monsaccharides which are absorbable.
8. List the 3 major pancreatic proteases. __________________ _____________________
__________________
9. Large fat drops are broken into smaller fat drops by ________________________ in the small intestine.
10. ___________________ salts keep small fat droplets in solution by a process called emulsification.
11. Lipase digests triglycerides and those products are surrounded by bile salts to form _________________________
12. Finally chylomicrons are absorbed into _____________________________________.
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