Study sets, textbooks, questions
Upgrade to remove ads
Terms in this set (64)
The lumen of the GI tract is part of ________________
the external environment
Neural and hormonal control of the GI tract occurs in three different phases depending on where the stimulus originates. These phases include the:
The cell type in gastric glands that secrete pepsinogen are called ___________ cells.
Put these in structures in the order that chyme passes through them during digestion, with the first at the top.
If a large food bolus does not reach the stomach during a given swallowing sequence, stretch of the esophagus initiates reflexive motility known as __________
Of the four histological layers that make up the wall of the intestinal tract, the one closest to the lumen is called the ___________
What are the four best understood GI tract hormones?
Glucose-dependent insulinotropic peptide
Which two of the following, when present in chyme, are mainly responsible for stimulating the secretion of cholecystokinin (CCK) by the small intestine?
Free fatty acids
T or F? The cephalic phase of GI control is defined as that initiated by receptors present upstream of the small intestine, including taste receptors and stomach stretch receptors.
Which three stimuli initiate gastric phase reflexes of the GI tract?
Amino acids and peptide concentration
The intestinal phase of regulation of the GI tract is initiated by stimuli in the ____________
Match these GI tract neural reflexes to their descriptions.
Short reflexes: begin at GI tract receptors and travel through enteric nervous system to effector cells
Long reflexes: begin at GI tract receptors, return signals to effectors from the CNS by way of autonomic nerve fibers
Arrange the layers of the wall of the GI tract form the closest to the lumen to the furthest form the lumen.
3. Muscularis externa
There are three pair of salivary glands, the _______________________________ glands
parotid, submandibular, and sublingual
Arrange in order the events of a local reflex coordinating intestinal motility and secretion.
1. Stretch and food particles occur inside the GI tract lumen
2. Chemoreceptors and mechanoreceptors in the tract wall are activated
3. Receptor activity stimulates neurons in the myenteric plexus and submucosal plexus
4. Smooth muscle and exocrine glands act as effectors
External or "extrinsic" control of motility and secretion in the GI tract is mediated by ____________
hormones; the autonomic nervous system
__________ is a non-enzymatic component of saliva that lubricates food particles and helps form them into a bolus for swallowing
In which two regions of the GI tract does the LEAST amount of digestion of food particles occur?
Smooth muscle is found in the wall of the ______________ of the esophagus
lower one third; middle one third
Which is FALSE regarding the function of the esophagus?
The lower esophageal sphincter remains open the entire time that a meal is being consumed, so food can pass easily into the stomach
Which of the following describes a main function of the lacteals found in the center of intestinal villi?
Uptake of absorbed fat
Following ingestion of meals, intense contractions of the large intestine known as ____________ occur
What three steps happen before the following?
1. Increased bicarbonate secretion in the pancreas
2. Increased flow of bicarbonate into small intestine
3. Neutralization of intestinal acid in the small intestine
Increased acid from stomach
Increased secretin secretion from small intestine
Increased plasma secretin
The most important component found in bile that contributes to digestion is __________
The recycling of bile salts from the liver to the intestines and back to the liver is known as the ____________
What stimulates contraction of the gallbladder and relaxation of the sphincter of Oddi?
Cholecystokinin secreted in response to a fatty meal
Match the carbohydrate to the correct category.
Glycogen -> polysaccharides
Sucrose -> Disaccharides
Glucose -> Monosaccharides
The substrate digested by salivary amylase is _____________
Glucose and galactose are absorbed from the lumen of the intestine into intestinal epithelial cells by _____________
secondary active transport
The two products of the digestion of triglycerides by pancreatic lipase are _________ and ____________
monoglycerides and free fatty acids
What characteristic of bile salts and phospholipids enables them to act as emulsifying agents?
They are amphipathic
Bile salts, fatty acids, monoglycerides, and phospholipids form ____________, which are similar in structure but much smaller than emulsion droplets.
Capillary blood from the interstitial wall containing absorbed nutrients travels first to the ____________ via the ___________
liver; hepatic portal vein
Select the 3 main functions of small intestine motility
Mixing luminal contents with exocrine secretions
Bringing luminal contents into contact with epithelial surface for abosprtion
Slowly advancing luminal contents towards the large intestine
The chemical digestion of complex carbohydrates begins in the ______________, but most starch digestion occurs in the _____________
mouth; small intestine
Phospholipids and bile emulsify ______
T or F? During the digestion of a meal, the most common form of motility in the small intestine in a peristaltic wave that begins in the duodenum and sweeps continuously to the end of the ileum.
The dominant form of motility in the small intestine during processing of a meal is ____________
stationary contractions and relaxations in a segmentation pattern that shuffles contentess back and forth
Segments of the colon include the _____________
Ascending colon; transverse colon; sigmoid colon; descending colon
T or F? Approximately 1500 mL of fluid moves into the lumen of the small intestine each day by osmosis, attracted by osmotic particles in chyme and be secreted Na+, Cl-, and HCO3-
Arrange the following steps in the order they occur in the pancreas; production and secretion of bicarbonate ions, with the final step at the top.
CO2 and H2O are converted to H2CO3 by carbonic anhydrase
H2CO3 dissociates into H+ and HCO3-
HCO3- is transported into the lumen in exchange for Cl-
____________ is an enzyme embedded in the apical plasma membrane of intestinal epithelial cells that splits off a peptide from _________________ to form the active enzyme trypsin
Pancreatic secretion of bicarbonate and enzymes increases during a meal, mainly as a result of stimulation by the hormones _________ and _______
T or F? Bile secretion followed by excretion of cholesterol in the feces is one of the mechanisms for maintaining cholesterol homeostasis in the blood.
Order the events involved in the absorption of fat from the first event to the last (top to bottom).
Fat incorporated into chylomicrons
Enters venous system
During the absorptive state of metabolism, glucose is used to form _____________ in skeletal muscle
In adipocytes during the absorptive state, glucose is used to form ____________
fatty acids; glycerol 3-phosphate; triglycerides
The lipid-protein aggregates synthesized by the liver from glucose during the absorptive state are secreted into the blood as
very low density lipoproteins
The enzyme lipoprotein lipase is found on the blood-facing surface of ______________
capillary endothelial cells
Glucose is stored as glycogen primarily in ______________
liver and skeletal muscle
Adipocytes are the site of storage of ______________
Which of the following statements about the transport of the absorbed products of fat digestion is TRUE?
Products of fat digestion first go to the lymph system, and then to the veins leading to the heart.
Which of the following pathways is activated during the cephalic phase of GI control?
Parasympathetic nerve to enteric nervous system
What are the 4 main fate of glucose when it is absorbed from the GI tract?
To the liver to form glycogen or triglycerides.
To the adipose tissue to form triglycerides.
To all tissues to be used for energy production.
To muscle to form glycogen.
What is the stimuli for release of the hormone secretin and what are its two inhibitory actions?
Release: acid in the small intestine
Inhibition: stomach acid secretion and stomach motility
Which of these events follows the absorption of glucose?
Glucose is converted to fat in the liver.
A protein molecule will be digested by enzymes made by:
The pancreas, stomach, and small intestine
What are the steps of the enterohepatic circulation?
Bile salts are secreted into bile and enter the duodenum via the common bile duct.
Bile salts are reabsorbed from the lumen of the ileum into the portal vein.
Liver cells (hepatocytes) reclaim the bile salts from the portal vein blood.
Excess absorbed glucose is initially converted to triacylglycerides and very low-density lipoprotein by
During the postabsorptive phase of metabolism
liver glycogen is broken down to glucose, which is released into the blood
Sarah has been diagnosed with pancreatic cancer. The first treatment is to remove 90% of her pancreatic tissue surgically. Due to the loss of exocrine tissue, which of the following foods will Sarah have more difficulty digesting post-surgery?
Starches, proteins and peptides, and lipids
Which occurs mainly in the small intestine?
Acidic chyme is neutralized
Which of the following molecules crosses the luminal membrane of intestinal cells by facilitated diffusion?
Which of the following statements regarding hormonal regulation of GI function is TRUE?
An increase of H+ in the small intestine stimulates secretion of the hormone secretin, which in turn stimulates HCO3- secretion by the pancreas.
Sets found in the same folder
CV Exam practice questions
RS Exam practice questions
Other sets by this creator
BIOC Midterm 1 Vocab
UR Practice Questions
Other Quizlet sets
ACC-162 Test 2
Honors Chemistry (Richards) Midterm