digestive system review
Of the approximately 9.0 L of fluids contained in the digestive tract daily, only __________ L are eliminated with the feces.
.15
HCl in the stomach produces a pH of between ________ in the luminal fluid.
1.5-2
Only about _______ ml of the 500 ml of chyme that entered the colon is voided as feces.
150ml
Peristaltic contractions of the stomach occur about _____ times per minute when food makes it into the body & fundus.
3-5
Of the approximately 800 g of food ingested during a typical day, only about ____ g are eliminated as undigested food in the feces.
50g
Which of the following carbohydrates is NOT a disaccharide?
50g
Which of the following neurotransmitters stimulates smooth muscle contraction in the digestive tract?
ACh
All preganglionic ANS fibers release _______ while only postganglionic fibers of the sympathetic division release _________.
ACh and NE
List the primary two mechanisms that control the motility and secretion of the digestive system.
ANS hormones
_______ _______protects the wall of the large intestine from mechanical damage and from damage by bacterial acid.
Alkaline mucous
The vomiting reflex is coordinated in the _________.
Brain stem
The hormone ______ released by the duodenum cause gastric motility to decrease when fats are present in the duodenum.
CCK
The hormone _______ causes the gall bladder to contract and release bile into the small intestine
CCK
The intestinal hormone _____ causes contraction of the gall bladder and release of bile into the duodenum.
CCK
Lipids in the intestine cause the release of the hormone_______, while acid in the intestine causes the release of ______.
CCK, Secretin
The frequency of segmentation contractions is greatest in the _____.
Duodenum
The ________ reflex describes the communication between the intestine and the stomach.
Enterogastric
Which of the following is under voluntary control?
External anal sphincter
Gastric emptying would be slowed by which of the following:
Fats in the duodenum Acids in the duodenum Hypertonic solutions in the duodenum Distention of the duodenum All of the above
The hormone _________ causes the ileocecal sphincter to relax during the gastric phase.
Gastric
The hormone ______ regulates gastric secretion during the gastric phase of digestion.
Gastrin
The ________ reflex stimulates mass movements of the colon.
Gastroileal
Pockets formed by the contractions of the transverse and descending colon musculature are called
Haustra
The process by which food is received into the GI tract via the mouth is called _____________________.
Ingestion
____ reflexes stimulate the ileum to increase activity when food is in the stomach
Long
During the inter-digestive period, _______ _______ _______ occur about once every 90 minutes to move undigested materials toward the terminal ileum.
Mass motility complexes
Sustained, intense propulsive peristaltic contractions of the large intestine are called __________ ___________.
Mass movements
_____ regulate gastric juice secretion during the cephalic phase.
Nerves
The frequency of peristaltic contractions is regulated by ________ cells.
Pacemaker
List three emotions that may produce constipation
Pain Fever Depression
________ division innervation stimulates watery, enzyme-rich saliva secretion, whereas ________ division innervation stimulates, a mucus-rich, more viscous saliva secretion.
Parasympathetic, sympathetic
The first wave of contraction of the esophageal muscles is called ______ ______.
Primary peristalsis
If a food bolus does not make it all the way to the stomach, _________ peristalsis forces the bolus the remainder of the way.
Secondary
List the two major functions of the large intestine.
Storage and concentration of feces Absorption of water,salt, and vitamin k
The function of the epiglottis is to prevent a bolus from entering the _____.
Trachea
Parasympathetic innervation to the salivary glands is transmitted by cranial nerves number_______ and _______.
VII, IX
Which of the following is a function of HCl in the stomach?
activates pepsinogen, breaks down cell waslls, kills most bacteria, denatures proteins in food
List two main divisions of the digestive system.
alimentary canal; accessory digestive organs
The breakdown products (monomers) of proteins are __________ _________.
amino acids
List the three major nutrient classes
amino acids; carbohydrates; fats
List the two main brush border proteases
aminopeptidase; dipeptidase
List the only two substances that are absorbed across the stomach's mucosal epithelium
aspirin and alcohol
Chylomicrons exit the intestinal epithelial cells and then enter the ________ lymphatic capillaries.
basement
The single digestive function of the liver is to produce _____.
bile
List the four organic components of bile:
bile salts, lecithin, cholesterol, bilirubin,
Absorption of nutrients occurs through the mucosal epithelium and into either _______ or ______ vessels.
blood; lymphatic
The microvilli of the small intestine's epithelial cells form the ______ border.
brush
Intestinal digestive enzymes that are embedded in the epithelial microvilli membranes are called ________ ________ enzymes.
brush border
The final digestion of carbohydrates is accomplished with ______ ______ enzymes.
brush border
List the four regions of the stomach:
cardia; fundus; body; pylorus
List the three phases of digestive system processes
cephalic, gastric, intestinal
Triglycerides combine with lipoproteins inside the intestinal epithelial cells to form __________.
chylomicrons
List the three sheets of muscle in the stomach's muscularis externa:
circular; longitudinal; oblique
Sympathetic nervous system stimulation ________ digestive system activity.
decreases
List, in order from the pylorus to the colon, the three regions of the small intestine:
duodenum; ileum; jejunum
_____ slow intestinal motility and cause the pyloric sphincter to contract.
enkephalins
_________ cells of the mucosa secrete hormones into the blood.
enteroendocrine
Intestinal ________ converts (activates) trypsinogen into trypsin.
enterokinase
The mucosa includes a type of columnar ________that forms the inner lining of the lumen
epithelium
Migrating motility complexes are controlled by the central nervous system. true or false
false
Most water and salt are absorbed in the colon. . true or false
false
Once food is acidified in the stomach, amylase continues to digest starch. true or false
false
Only single amino acids are absorbed in the small intestine. true or false
false
Secretin stimulates gastric HCl secretion.
false
Segmentation moves chyme in only one direction. true or false
false
The cephalic phase of digestion is regulated by short reflexes. true or false
false
The colon epithelium produces substantial amounts of digestive enzymes. true or false
false
The esophagus is digestive in function. true or false
false
The esophagus secretes digestive enzymes. true or false
false
The breakdown products of triglycerides include monoglycerides and _______ _________.
fatty acids
List four functions of duodenal CCK.
gallbladder contraction and release of bile release digestive enzymes inhibits gastric emptying stimulates growth of pancreas and gall bladder mucousa
List 5 peptide hormones of the GI tract:
gastrin, cholecystokinin, secretin, glucose dependent insulinotropic peptide, motilin
List the two secretions that stimulate HCl release from parietal cells.
gastrin, histamine
Gastric motility ________ as the stomach begins to receive food.
increases
The muscularis mucosa has both ________ and _______ fibers that function in moving the villi to aid in digestion and absorption.
inner circular; outer longitudinal
GIP stimulates the pancreas to secrete_________.
insulin
The pancreatic hormone _______ regulates the absorptive state, while ______ regulates the postabsorptive state.
insulin, glucagon
Without _______ _______, vitamin B12, necessary for normal RBC development, can not be absorbed by the intestine.
intrinsic factor
Blood and lymph vessels of the mucosa are found in its ______ _______ connective tissue layer.
lamina propria
Pancreatic __________ is responsible for the majority of fat digestion.
lipase
During the cephalic phase _________ neural reflexes stimulate an increased production of gastric juice.
long
Digestive system reflexes that involve the brain are called ______ _______.
long reflexes
A meal consisting largely of fatty foods will take __________ to digest than a meal consisting of mainly of starchy food
longer
Bile salts surround monoglycerides and free fatty acids to form tiny droplets called ________.
micelles
From largest to smallest, list the three modifications of the small intestine's inner wall that function to increase surface area:
microvilli; villi; circular layer of muscle
______ stimulates motility of the intestine, thereby moving its contents toward the terminal ileum.
motilin
The four main layers of the digestive tract wall are
mucosa, submucosa, muscularis, serosa
The four main components of gastric juice are:
mucous, pepsinogen, HCl, intrinsic factor
The function of epithelial goblet cells is to secrete ________.
mucus
The smooth muscle layer of the mucosa is called the ________ _______.
muscularis mucosae
The built-in (intrinsic) network of nerve cells in the submucosa is the ______ ______.
nerve plexus
The network of neurons in between the two muscle layers of the muscularis externa is the ___________ ___________.
nerve plexus
Gastrin producing G-cells are found in the gastric glands located in the ________ region of the stomach
pH
The main digestive enzyme-producing organ in the body is the ______.
pancreas
The digestive enzyme ________ begins the breakdown of proteins in the stomach.
pepsin
The two types of movements produced by contractions of the muscularis externa are ____________ and ____________.
peristalsis; segmentation
Sympathetic NS innervation of the digestive tract is via____________ fibers.
postganglionic
_______ occurs when the combined action of two hormones is greater than the sum of their individual effects.
potentiation
List the four major functions of saliva.
protection, taste, lubrication, digestion
Gastrin is released from the ______ region of the stomach
pyloric
Three pairs of _____ _____ function to moisten food in the mouth.
salivary glands
List the three main substances that are absorbed in the large intestine.
salt, water, vitamins B&K
List the 4 main responses during the intestinal phase of digestion
secretion of bicarbonate secretion of digestive enzymes release of bile segmentation contractions of SI
List the two mechanisms that help to increase the surface area of lipids for subsequent digestion with pancreatic lipase.
segmentation; emulsification
Which of the following is not typically a stimulus for the vomiting reflex?
sleep
The small intestine typically________.
slows gastric emptying
The stimulation of __________ receptors triggers the gastric phase of digestion.
stomach stretch
The anus is lined with ______ _______ epithelium
stratified squamous
The mouth, with its ____ ____ epithelium, is involved in both chemical and ____ digestion.
stratified squamous; mechanical
The ___________ and ______________ plexuses are the two components of the enteric nervous system.
submucosal and myenteric
Name the brush border enzymes.
sucrase, dextrinase, glucoamylase
Both the sympathetic and parasympathetic divisions of the ANS stimulate the salivary glands. . true or false
true
Pepsin is inactivated in the duodenum.. true or false
true
Swallowing has both voluntary and involuntary components. true or false
true
The active transport of sodium is necessary for water absorption in the small intestine.
true
List the three major pancreatic proteases.
trypsin; chymotrypsin; carboxypeptidase
List the three major proteases (inactive forms) secreted by the exocrine pancreas
trypsinogen, chymotrypsinogen, procarboxypeptidase
List the 6 sphincters of the digestive tract:
upper esophageal; lower esophageal; pyloric; ileocecal' anal; external anal
The _______ nerve carries electrical signals from the brain to the stomach.
vagus
The ___________ nerve triggers the responses during the cephalic phase of digestion
vagus
The ____________ and _________ ____________ nerves carry parasympathetic impulses to the enteric nervous system.
vagus and pelvic splanchnic
Colic bacteria produce substantial quantities of ________ ___ as a by product of their metabolism.
vitamin K
The large intestine absorbs __________, __________, and ___________.
water; electrolytes; vitamins
