Chapter 18: Connect Homework
Secretin
-potentiates the effects of acetycholine on the acinar cells through the action of cyclic AMP as a second messenger -secreted in response to a decrease duodenal pH below 4.5 -stimulates the production and secretion of bicarbonate into the pancreatic juice -stimulates the bile duct cells to secrete bicarbonate into the bile
Cholecystokinin (CCK)
-stimulates trypsin, lipase, and amylase from the pancreas -stimulates acinar cells using a rise in cytoplasmic calcium as a second messenger -stimulated in response to protein and fat content in chyme -secretion continues until chyme passes through the duodenum and in the early region of the jejunum
the combination of chewed food and saliva is called
a bolus
Acidic chyme is buffered by ________ secreted from the pancreas.
bicarbonate
the negative feedback control of HCI secretion in the gastric phase of gastric regulation is mainly by ______ secretion
both decrease in gastrin secretion and increase in somatostatin secretion are correct
the outer surface bulges of the large intestine are called
haustra
bile pigment is a derivative of
heme group without iron
bile is produced by
hepatocytes
If plasma levels of ________ were low, excessive cholesterol may be deposited throughout the body tissues, and cardiovascular risk could increase.
high-density lipoprotein
antihistamines would directly limit the gastric secretion of
hydrochloric acid
the _____ reflex inhibits gastric motility
ileogastric
vitamin B12 is primarily absorbed in the ____
ileum
vitamin b12 is primarily absorbed in the
ileum
enterogastrone will _____ gastric function
inhibit
The arrival of chyme in the duodenum stimulates a neural reflex that inhibits gastric activity
intestinal phase
The ENS also contains _______ afferent neurons that do not synapse with neurons in the spinal cord
intrinsic
The _______ afferent neurons greatly outnumber the ______ emphasizing the importance of local control of intestinal function
intrinsic, extrinsic
Which of the following are heptic phagocytic cells of the reticuloendothelial system?
kupffer cells
which of the following are heptic phagocytic cells of the reticuloendothelial system
kupffer cells
bile duct
label 1
general circulation
label 1
serosa
label 1
Gallbladder
label 10
common bile duct
label 11
liver
label 12
fat droplets (triglycerides)
label 2
kidney
label 2
longitudinal muscle
label 2
circular muscle
label 3
emulsified fat droplets
label 3
hepatic portal vein
label 3
Urobilinogen in urine
label 4
monoglycerides
label 4
muscularis
label 4
Urobilinogen in feces
label 5
micelles
label 5
villi
label 5
free fatty acids
label 6
lacteal
label 6
urobilinogen
label 6
bacteria
label 7
mucosa
label 7
Bilirubin
label 8
submucosa
label 8
small intestine
label 9
essential for hydrolysis of triglycerides
lipase
lipid digestion and absorption requires the coordinated actions of ____ and ____
lipase; bile
which of the following motility processes is NOT correctly matched to its description
mastication- removal of wastes
which of the following motility processes is NOT correctly matched to its description?
mastication-removal of wastes
Broken apart by the brush border for absorption
mixed micelles
in which of the following areas does carbohydrate digestion occur?
mouth and duodenum
Damage to which tunic of the GI tract would directly affect Auerbach's plexus?
muscularis
The ENS is organized into an outer ______ plexus and an inner _______ plexus located only in the small and large intestine.
myenteric, submucosal
movement of water out the large intestine is by
osmosis
the enzyme with the most basic pH optimum is
pancreatic lipase
helicobacter pylori is a bacterium associated with
peptic ulcers
Wavelike muscular contraction of the gastrointestinal tract is called______
peristalsis
inhibition of exocrine pancreatic secretions would result in
presence of an acidic chyme
what is the function of paneth cells of the small intestine
produce lysozyme and defensins
most of the glucose is absorbed in the epithelial cells of the small intestine by
secondary active transport with Na+
the mixing movement of the small intestine is called
segmentation
Place the tunics of the GI tract wall in the correct order from superficial to deep.
serosa, muscularis, submucosa, mucosa
Reformed within the epithelial cells
triglycerides
Excess use of antibiotics can kill the normal intestinal microflora and open a niche for pathogenic bacteria.
true
Micelles, made of bile salts, have hydrophilic and hydrophobic regions that allow them to emulsify fats and dissolve in water.
true
The peptidase category of enzymes includes aminopeptidase and enterokinase.
true
There are significantly more microbiota in the large intestine than there are cells in the entire human body
true
medications that block HCI secretion may impact the conversion of pepsinogen to pepsin
true
some intestinal microbiota produce short-chain fatty acids, which account for about 10% of the calories in a Western diet.
true
the brush border enzymes that digest sugars include sucrase, maltase, and lactase
true
the enzyme activity of the phosphatase category of brush border enzymes may be regulated by vitamin D
true
the low pH provided by HCI secretion allows the pepsin enzyme to be freed from pepsinogen enzymes
true
the vagus nerve stimulates gastrin secretion during the cephalic phase of gastric function
true
the primary function of the large intestine is
water and electrolyte reabsorption
pepsin would have the greatest activity
when the pH of the chyme is less than 3
somatostatin is produced in the stomach by ___ cells
D
protection against atherosclerosis is believed to be associated with an elevated
HDL-cholestorol
the stomach churns food into a pastry material is called
chyme
the stomach churns food into a pasty material is called
chyme
juandice is characterized by high blood levels of _____, often caused by obstruction of the bile duct by gallstones
conjugated bilirubin
Free amino acids are absorbed into the blood stream by
contransport with Na+
The ENS contains _______ afferent neurons which are regulated by the ANS
extrinsic
Brush border enzymes are secreted into the lumen, where they become activated
false
HCI secretion is necessary in order for pepsin to complete the final steps of protein digestion
false
alkaline phosphate is necessary for the activation of the protein-digesting enzyme trypsin.
false
both pepsin and HCI are enzymes necessary to begin protein digestion
false
intestinal microbiota are generally not beneficial to digestive processes, such as absorption
false
the commensal microbiota in the intestines are not usually present at birth but are acquired through infections and ingestion of bacteria
false
amino acids and peptides in the stomach lumen stimulate acid secretion during the ______ phase of gastric secretion
gastric
Stomach distension stimulates vagus nerve, resulting in acid secretion; amino acids and peptides in stomach stimulate acid secretion
gastric phase
which hormone stimulates ECL cells to secrete histamine which stimulates HCI release from parietal cells
gastrin
Which of the following disorders occurs as a result of acidic gastric juice traveling up into the esophagus
gastroesophageal reflux disease
what is the function of enterokinase secreted by the brush border?
activates the protein-digesting enzyme trypsin
the first line of defense in the stomach against damaging acid and pepsin is the
adherent layer of mucus
What commonly ingested substances are absorbed through the stomach wall?
alcohol and aspirin
slow waves of the intestine are produced by what type of cells
cajal
sight, smell, and taste of food cause stimulation of vagus nuclei; vagus stimulates gastric acid secretion
cephalic phase
Ultimately enters the venous system
chylomicrons
The _______ of the stomach and intestine secrete histamine and serotonin
enterochromaffin-like (ECL) cells
trypsin is activated by the enzyme ______
enterokinase
