chapter 25 - digestive system
Which of the following is a function of the bacterial flora?
-bacteria digest cellulose -bacteria synthesize vitamin K
which secretions enter the GI tract at the duodenum?
-bile -chymotrypsinogen -pancreatic lipase -ribonuclease -deoxyribonuclease
which structures are part of the digestive tract?
-buccal cavity -duodenum -jejunum -ileum -colon -rectum
What are the segments of the small intestine in the order through which food passes?
-duodenum -jejunum -ileum
Starting after it leaves the pyloris, place the following anatomical structures in order to identify the correct sequence that food would pass through the body.
-duodenum -jejunum -ileum -cecum -ascending colon -transverse colon -descending colon sigmoid colon -rectum
which secretions enter the GI tract at the stomach?
-pepsinogen -HCl -intrinsic factor
which characteristics describe the small intestine?
-plicae -villi -brush border -microvilli -maximized surface area for absorption -aggregated lymphoid nodules
which characteristics describe the stomach?
-rugae -gastric pits -oblique layer in muscularis -maximized size for storage and mixing
which secretions enter the GI tract at the buccal cavity?
-salivary amylase -lingual lipase
Which of the following is a method of motility in the small intestine?
-segmentation -peristalsis -migrating motor complex
which structures are accessory organs to the digestive tract?
-teeth -salivary glands -liver -gallbladder
Which of the following statements is/are true about gastric motility?
-the stomach uses the contraction of 3 layers of muscle to mix, churn, and propel its contents to the duodenum -when the pyloric sphincter relaxed, chyme moves from the stomach to the duodenum -the receptive-relaxation response of the stomach allows it to accommodate more food
The following anatomical features of the small intestine function to increase the surface area of the intestinal wall and maximize its capacity for absorption. Rank these structures 1 through 3 in order from largest to smallest. -villi -circular folds -microvilli
1.circular folds 2.villi 3.microvilli
what is the function of the enzyme glucoamylase?
Brush-border enzyme that breaks down oligosaccharides
what is the function of the enzyme maltase?
Brush-border enzyme that targets the release of glucose from maltose
what is the function of the enzyme deoxyribonuclease?
Enzyme that breaks down DNA
what is the function of the enzyme ribonuclease?
Enzyme that breaks down RNA
what is the function of the enzyme salivary amylase?
Hydrolyzes starch, but is deactivated in the stomach
In order for digestion to occur, chyme is required to contact the microvilli of the intestinal wall because the __________.
brush border enzymes are not secreted into the lumen
Gastric secretion begins during the __________ phase and ends during the __________ phase.
cephalic; intestinal
which cells secrete the digestive enzymes, gastric lipase and pepesinogen?
chief cells
The network of nerves that regulate digestive motility, secretion, and blood flow is called the __________ system.
enteric nervous
which cells secrete hormones and paracrine messengers?
enteroendocrine cells
what is the function of the enzyme pancreatic lipase?
enzyme that produces 2 free fatty acids and a monoglyceride
What is the straight muscular tube conveying food from pharynx to the stomach called?
esophagus
TRUE/FALSE? As long as there is chyme in the duodenum, it will continue to stimulate gastric secretion.
false
The hormone __________ stimulates the secretion of the enzyme __________ in the stomach.
gastrin; pepsinogen
What are the microscopic structural subunits of the liver?
hepatic lobules
Secretin is released from the duodenum in response to _________.
hydrochloric acid and chyme
Which of the following describes the fundus of the stomach?
it is the domed superior region
what is the function of the enzyme lingual lipase?
mouth-secreted enzyme that increases in activity upon contacting the HCl of the stomach
which cells secrete mucus and predominate in the cardia and pylorus?
mucous cells
Stimulation from the __________ nervous system via the __________ nerve causes the secretion of HCl in the stomach.
parasympathetic; vagus
which cells secrete hydrochloric acid, intrinsic factor, and ghrelin?
parietal cells
Which of the following enzymes is produced by the stomach?
pepsin
which cells divide rapidly and and provide a continuous supply of new cells?
regenerative cells
Which does not stimulate the secretion of HCl in the stomach?
secretin
Cholecystokinin, which is produced in the small intestine, inhibits gastric secretions in the stomach.
true
Secretin is released from the duodenum in response to acidic chyme.
true
TRUE/FALSE? Gastrin functions to increase the production of HCl in the stomach.
true
