Unit XII (63-67) - Gastrointestinal Physiology Flashcards by Aida Vientos-Plotts

Ptyalin in the saliva hydrolyzes starch into which disaccharide?
A.	Fructose
B.	Glucose
C.	Lactose
D.	Maltose
E.	Sucrose

D. Maltose

Ref: Guyton, Ch.66 pg. 834

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Which of the following pancreatic enzymes leads to digestion of proteins into individual amino acids?
A. Trypsin
B. Carboxypolypeptidase
C. Chymotrypsin
D. Aminopolypeptidase

Ref: Guyton p 835

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Which of the following is not a potential stimulus for gastric acid secretion?

a. Norepinephrine secretion resulting from stimulation of sympathetic nerves.
b. Vagal nerve activity resulting from the sight of food.
c. The presence of undigested protein in the pyloric antrum.
d. Acetylcholine release stimulated by gastric stretch receptors acting on nerves of the ENS.
e. Histamine release from cells in the gastric mucosa.

Cunningham Ch. 29

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Which gastrointestinal hormone is released in response to digestive products in the intestines and causes gallbladder contraction and release of bile, inhibits stomach contraction, and inhibits appetite?

a. Gastric inhibitory peptide
b. Cholecystokinin
c. Gastrin
d. Secretin

b. Cholecystokinin

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Which of the following is true regarding hydrochloric acid secretion in the parietal cells?

a. H+ is secreted from the apical membrane of the parietal cell via facilitated diffusion
b. H+-K+ ATPase works at the basolateral membrane to load the parietal cell with hydrogen ions
c. Bicarbonate is formed by carbonic anhydrase and transported out of the parietal cell by the bicarbonate chloride cotransporter
d. H+ is pumped into the lumen by active transport from a H+-K+ ATPase at the apical membrane of the parietal cell

d. H+ is pumped into the lumen by active transport from a H+-K+ ATPase at the apical membrane of the parietal cell

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Saliva contains high concentrations of which two ions?

a. bicarbonate and sodium
b. sodium and chloride
c. chloride and bicarbonate
d. bicarbonate and potassium

d. bicarbonate and potassium

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The extrinsic innervation of the gut consists of:

a. The enteric nervous system.
b. The myenteric and submucosal plexuses.
c. Sympathetic (splanchnic) and parasympathetic (vagus) nerves.
d. Sympathetic (vagus) and parasympathetic (splanchnic) nerves.
e. The pelvic nerve

Cunningham Ch. 27

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What are the anatomical differences between the esophagus of dogs, cats and horses?

Dogs, cattle and sheep, its entire length is striated muscle

Cats, horses and humans, the proximal esophagus has striated muscle and the distal esophagus smooth muscle.

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Which of the following hormones stimulates insulin release?
A. Gastrin
B. CCK
C. Gastric Inhibitory Peptide
D. Motilin

C. Now known as glucose dependent insulinotrophic peptide

Ref. Guyton 802

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Which of the following are effects of the gastric hormone secretin?

a. Stimulation of mucosal endothelial growth
b. Promotion of insulin secretion
c. Promotion of bicarbonate secretion
d. Stimulate gastric acid secretion

c. Promotion of bicarbonate secretion

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Intrinsic factor must be present in gastric secretions to allow for adequate absorption of vitamin \_\_\_\_ in the ileum. Without intrinsic factor, pernicious anemia can occur. 
A.	B6
B.	B12
C.	C
D.	D
E.	E

B. B12

Ref: Guyton, Ch. 67 pg. 844

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Inhibition of the enzyme carbonic anhydrase is likely to have what effect on gastric pH?

a. Decrease gastric pH
b. Increase gastric pH
c. Have no effect on gastric pH

Cunningham Ch. 29

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The term slow waves as applied to the gut refers to:
a. Slowly moving fronts of electrical activity that are propagated down the enteric nervous system.
b. Slowly moving fronts of electrical activity that result from coordinated changes in cell membrane potential occurring throughout the smooth muscle of the intestinal wall.
c. Slowly moving fronts of ingesta that proceed down the intestine in response to peristaltic movement.
d. Slowly moving fronts of action potentials that are constantly passing over the gut smooth muscle.
e. Slowly moving fronts of peristaltic contractions that pass uniformly over the entire small intestine during the digestive
period.

Cunningham Ch. 28

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The ____________ reflex occurs as a result of distension of the stomach and duodenum after a meal and is transmitted by way of the autonomic nervous system.

a. Defecation
b. Enterogastric
c. Gastrocolic
d. Gastroileal

c. Gastrocolic

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What factor does not contribute to depolarization of intestinal smooth muscle?

a. Stretching of the muscle
b. Sympathetic stimulation by norepinephrine release
c. Stimulation by several gastrointestinal hormones
d. Parasympathetic stimulation by acetylcholine

b. Sympathetic stimulation by norepinephrine release

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Which of the following causes decreased blood flow to the gastrointestinal tract? 
A. CCK
B. Bradykinin
C. Adenosine
D. Sympathetic stimulation

D. sympathetic stimulation

Ref. 805

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Which of the following hormones inhibits small intestinal peristalsis? 
A. Gastrin
B. CCK
C. Insulin
D. Secretin
E. Motilin 
F. Serotonin

D. Secretin

Glucagon can also inhibit motility in small intestine

Guyton 13th ed Ch. 64

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Irritation of the peritoneum results in which of the following neurologic reflexes?

a. peritoneointestinal reflex – the strong inhibition of excitatory enteric nerves resulting in intestinal paralysis
b. peritoneoenteritis reflex - the strong inhibition of excitatory enteric nerves resulting in intestinal paralysis
c. peritoneointestinal reflex – the strong excitation of the enteric nervous system inducing hypermotility
d. renointestinal reflex - the moderate inhibition of excitatory enteric nerves resulting in intestinal paralysis

a. peritoneointestinal reflex – the strong inhibition of excitatory enteric nerves resulting in intestinal paralysis

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The enteric nervous system is composed mainly of two plexuses. Which one controls mainly gastrointestinal secretion and local blood flow?

a. Myenteric plexus
b. Mucosal plexus
c. Submucosal plexus
d. Parasympathetic plexus

Answer: c

Guyton (12th ed.) p. 755

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List the steps in HCL production by the parietal cell

H2O + CO2 + carbonic anhydrase = H2CO3 (carbonic acid)
Carbonic acid dissociates into:
a. H+ - active transport in the apical membrane into the lumen
b. Bicarb - exchanged with Cl in the basolateral membrane
Cl diffuses through the apical membrane into the lumen
In the lumen H+ + Cl- = HCl

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Which of the following hormones stimulates gastric acid secretion?
A. Gastrin
B. CCK
C. Secretin
D. Motilin

A. Gastrin

Ref. Guyton 802

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An animal is presented to you with aspiration pneumonia (the result of food material entering the lower respiratory tract). Which of the following lesions would be a likely cause?

a. Loss of myenteric plexus function in the pharynx and upper esophagus
b. Loss of slow-wave activity in the pharynx and upper esophagus
c. A lesion in the brainstem
d. A lesion in the trachea
e. None of the above

Cunningham Ch. 28

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What is the source of the most important signal that regulates gastric emptying?
A. Stomach
B. Duodenum
C. Ileum
D. Colon

B. Duodenum

Guyton 13th ed p. 811

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Which of the following is required for normal absorption of cobalamin in the ilium?

a) enterokinase
b) glucose-dependent insulinotropic peptide
c) intrinsic factor
d) pepsinogen

Answer C

Guyton pg. 844

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Damage to which of these neurologic structures can result in paralysis of the swallowing mechanism? A. CN V, IX, X, & swallowing center of the brainstem B. CN V, IX, & X C. CN V, VII, & XII D. CN V, IX, X, XII, & swallowing center of the brainstem

Answer D V - trigeminal - sensory to face and motor to m of mastication IX - glossopharyngeal - muscles of swallowing X - vagus - efferent XII - hypoglossal - motor to tongue efferent nerve fibers from swallowing center in the brainstem travel in the facial, vagus, hypoglossal and glossopharyngeal nerves and motor branch of trigeminal Cunningham p 276

Which of the following is the most important enzyme for starch digestion? a) Ptyalin b) Pancreatic Amylase c) a-dextrinase d) maltase

B. pancreatic amylase Ptyalin - (also an amylase but just in saliva) Alpha dextrinase - disaccharides Maltase - maltose Guyton pg. 834

``` The myenteric plexus is inhibited by which of the following hormones? A. Gastrin B. CCK C. Secretin D. VIP - vasoactive inhibitory peptide ```

D. VIP (thought to be but not for sure) Ref. Guyton 800

Which cell in the pyloric glands is responsible for secreting histamine in response to stimulation by gastrin? a. Parietal cells b. Chief cells c. Enterochromaffin-like cells d. Goblet cells

c. Enterochromaffin-like cells

``` Which of the following aspects of colon physiology is common to many species, irrespective of interspecies anatomical differences in colon structure? a. Rapid flow of ingesta b. Adaptive relaxation c. Retropulsion, or antiperistalsis d. Haustra formation ```

C Cunningham Ch. 28

Which of the following is characteristic of the inter digestive phase of small intestinal motility? a. Migrating motility complexes consisting of waves of peristaltic contractions that pass over the entire length of the small intestine b. Rhythmic segmentation c. Short waves of peristalsis that die out after a few centimeters d. Complete relaxation of small intestinal smooth muscle

A Cunningham Ch. 28

This reflex results when food stretches the stomach allowing for the stomach reducing the tone of the muscular wall a. Vasovagal reflex b. Gastrocolic reflex c. Gastroenteric reflex d. Gastroesophageal reflex

a. Vasovagal reflex

``` Most proteins are absorbed through intestinal epithelial cells in the form of dipeptides, tripeptides, and a few free amino acids. By what mechanism are most absorbed? A. Co-transport B. Facilitated diffusion C. Simple diffusion D. Primary active transport ```

Answer A. Co-transport Guyton Pg 841

``` Action potentials in the GI smooth muscle are potentiated by the influx of which ion? A. Cl- B. Na C. Ca D. K ```

C. Ref. 799

Parietal cells within the gastric glands release __________, which is needed for absorption of vitamin B12 in the ileum. a. Intrinsic factor b. Hydrochloric acid c. Cortisol d. Histamine

a. Intrinsic factor

Which of the following best describes the motility of the proximal region of the monogastric stomach? a. Rhythmic segmentation b. Peristalsis c. Retropulsion d. Adaptive relaxation

D Cunningham Ch. 28

Which of the following ions has higher concentrations in saliva compared to plasma? a. Calcium b. Chloride c. Potassium d. Sodium

c. Potassium

What factor within the duodenum cannot initiate enterogastric inhibitory reflexes? a. Distension of the duodenum b. Irritation in the duodenal mucosa c. Alkalitity of the duodenal chyme d. Osmolality of the chyme

c. Alkalitity of the duodenal chyme

Which one of the following hormones is secreted by K cells? a. Cholecystokinin b. Secretin c. Motilin d. Gastric inhibitory peptide

d. Gastric inhibitory peptide

Which nerve controls the external anal sphincter? a. Pelvic nerves b. Pudendal nerve c. Myenteric plexus d. Obturator nerve

b. Pudendal nerve

Which of the following accurately describes forward movement of a food bolus through the gastrointestinal tract? A. The swallowing center is located in the medulla and pons of the CNS. B. The movement of a food bolus through the esophagus is passive and only performed by smooth muscle. C. The stomach processes food and has no storage capacity. D. Having hunger pangs (I.e. being "hangry") does not exist, and the stomach does not contract strongly with prolonged emptying.

A. The swallowing center is located in the medulla and pons of the CNS.

``` Which of the following gasses are formed from bacteria in the large intestine? A. Methane, nitrogen, carbon dioxide B. Oxygen, carbon monoxide, methane C. Hydrogen, methane, and carbon dioxide D. Carbon monoxide, methane, hydrogen ```

Answer C. Hydrogen, methane, and carbon dioxide Guyton Pg 849

Which one of the following electrolytes has the highest concentration in bile secreted from the gallbladder? a. Na b. K c. Ca d. Cl

a. Na

The main driving force for hydrochloric acid secretion by the parietal cells is… a. H-K ATPase b. Cl-HCO3 antiporter c. Na-K ATPase d. Cl diffusion

a. H-K ATPase

Which of the following is most responsible for creating an action potential in gastrointestinal smooth muscle and accounts for the long duration of action potential seen? a. Chloride channels b. Calcium-sodium channels c. Fast sodium channels d. Potassium channels

b. Calcium-sodium channels

Which of the following is not a natural ligand for receptors in the pancreas? a. Cholecystokinin b. Acetylcholine c. Gastrin d. Secretin

C Cunningham Ch. 29

``` Chloride is absorbed in which primary locations in the gastrointestinal tract? A. proximal small intestine & ileum B. duodenum C. ileum D. colon ```

Answer A | pg. 839

``` Which of the following cells are considered the pacemakers of the GIT? A. G cells B. Cells of Cajal C. I cells D. K cells ```

B. Ref. 798

``` Which of the following hormones inhibits gastric acid secretion? A. Gastrin B. CCK C. Secretin D. Motilin ```

C. Ref. Guyton 802

``` Which of the following causes the GI smooth muscle hyperpolarization? A. Stretch B. Acetylcholine C. Hormones D. Norepinephrine ```

D. Norepi Ref. Guyton 799

The rectosphincteric reflex is integrated in the: a. Brainstem. b. ENS. c. Lumbar spinal cord. d. Sacral spinal cord

D Cunningham Ch. 28

Pepsin becomes inactivated and has no proteolytic activity above: a. pH 3 b. pH 5 c. pH 7 d. pH 9

b. pH 5

Bile salts have two primary actions, what are they? a. (1) act as a detergent or emulsifying agent to decrease surface tension and (2) facilitate absorption from the intestinal tract b. (1) act as a detergent to increase surface tension and (2) facilitate absorption from the intestinal tract c. (1) induce absorption of food from the gastrointestinal tract and (2) induce digestion of chylomicrons within the lymphatic system d. (1) regulate electrolyte absorption and secretion within the intestinal tract and (2) digest fatty acids

a. (1) act as a detergent or emulsifying agent to decrease surface tension and (2) facilitate absorption from the intestinal tract

``` Glucose is transported into the cell via: A. Facilitated diffusion B. Primary active transport C. Secondary active co - transport D. Secondary active counter transport ```

C. Secondary active co transport occurs more commonly in GI and renal cells, in all other cells glucose enters the cell via facilitated diffusion. Ref: Guyton p 840

Which factor(s) stimulate pepsinogen secretion by the peptic cells ? a. Acetycholine only b. Acetylcholine and gastrin c. Acetylcholine and secretin d. Cholecystokinin only

Answer : a | Guyton (12th ed.) p. 779

The normal resting membrane potential of gastrointestinal smooth muscle cells is: a. -80 to -90 mV b. -105 to -110 mV c. -50 to -60 mV d. -30 to -40 mV

c. -50 to -60 mV

``` Which of the following can occur as complications to chronic gastritis? I. Achlorhydria II. Ulcerative colitis III. Peptic ulcer IV. Pernicious anemia ``` a) III, IV b) I, IV c) I, III, IV d) I-IV

Answer: c Source: Guyton ed 13, Ch 67, page 844

The control of glandular secretion is mostly due to local stimulation in which of the following locations? a. Jejunum b. Salivary c. Rectum d. Pancreas

a. Jejunum

1. A unique feature of gastrointestinal (GI) smooth muscle cells is that: a. Their resting transcellular electrical potential has the positive pole on the outside surface of the cell membrane. b. Action potentials, or spikes of membrane depolarization, are not associated with muscle contractions. c. Muscle contractions are stimulated by partial depolarization of the membrane. d. There are spontaneous, rhythmical undulations in the electrical potential across the cell membrane. e. Contraction of the muscles is never influenced by nervous activity.

D Cunningham Ch. 28

Which hormone is released from the G cells, stimulating mucosal growth? a. Gastrin b. CCK c. Secretin d. GIP

a. Gastrin

Conditions in the duodenum, such as low pH or high fat concentration, can reflexively inhibit gastric emptying. Which reflex arc is involved in this inhibition? a. Parasympathetic nervous system b. GI enteric nervous system c. GI endocrine system d. All the above

D Cunningham Ch. 28

The neurotransmitters in the gut are: a. NO and Ach as excitatory, and substance P and VIP as inhibitory. b. NO and Ach as inhibitory, and VIP and substance P as inhibitory. c. NO and VIP as excitatory, and Ach and substance P as inhibitory. d. NO and VIP as inhibitory, and Ach and substance P as excitatory. e. NO and substance P as inhibitory, and Ach and VIP as excitatory.

D Cunningham Ch. 27

``` Which of the following hormones stimulates gastric motility? A. Gastrin B. CCK C. Secretin D. Motilin ```

D. Motilin Ref. Guyton 802

Secretion of gastric inhibitory peptide from the K cells of the duodenum and jejunum is stimulated by protein, fat, and carbohydrates. What does secretion of gastric inhibitory peptide stimulate? a. Insulin release b. Gastric acid secretion c. Pepsin secretion d. Biliary bicarbonate secretion

a. Insulin release

Which of the following is secreted by activated salivary cells and is important in enzymatic formation of bradykinin? a. cAMP b. Kallikrein c. Secretin d. Pepsin

b. Kallikrein

In what specific location in the gastrointestinal tract is the intestinal phase of gastric secretion initiated? a. Stomach b. Duodenum c. Ileum d. Jejunum

b. Duodenum

Cholecystokinin and gastrin: a. Share all of the same receptors. b. Share CCK1 receptors. c. Share CCK2 receptors. d. Share gastrin I receptors. e. Share gastrin II receptors

C Cunningham Ch. 27

Which of the following correctly describes the secretion or action of secretin? a. Secretion is mainly stimulated by the presence of carbohydrates in the duodenum b. Secreted from the stomach c. Decreases stomach acid production d. Secretin’s main effect is increasing intestinal motility

c. Decreases stomach acid production

Which of the following hormones stimulates insulin release? a. Cholecystokinin b. Gastrin c. Gastric Inhibitory Peptide d. Motilin

c. Gastric Inhibitory Peptide

2. The interstitial cells of Cajal are: a. Modified neurons capable of generating contraction. b. Modified neurons capable of generating only action potentials. c. Modified neurons capable of generating only slow waves. d. Modified smooth muscle cells capable of generating only slow waves. e. Modified smooth muscle cells capable of generating only action potentials.

D Cunningham Ch. 28

Colonic “pacemakers”: a. Are anatomically distinct structures composed of specialized smooth muscle cells. b. Shift in their sites under the influence of the ENS. c. Are involved in segmentation, but not peristalsis. d. Control defecation.

B Cunningham Ch. 28

The cholera toxin specifically targets which area of the gastrointestinal tract? a. duodenum b. duodenum, jejunum, and ileum c. distal ileum and colon d. colon only

C. Distal Ileum and Colon (location of crypts of liberkun) The enterocytes in these crypts are responsible for water secretion toxin --> increase cAMP --> Cl channels open --> Cl loss activates Na pump--> Na into lumen --> H2O follows Na --> excess water loss --> diarrhea Guyton p. 846

``` Which of the following hormones stimulates gallbladder contraction? A. Gastrin B. CCK C. Secretin D. Motilin ```

B. CCK Ref. Guyton 802

Which of the following reflexes occurs as a result of chyme entering the duodenum? a. gastroileal reflex b. gastroenteric reflex c. mienteric reflex d. viscointestinal reflex

b. gastroenteric reflex

Which enzyme is most active at a pH of 2.0 to 3.0 and plays an important role in digesting collagen? a. Alpha dextrinase b. Amylase c. Pepsin d. Elastase

Answer: C. Reference: Guyton Ch. 66 Pg. 835

3. Which of the following reactions in the liver could be expected to occur during both the digestive phase and a prolonged fast? a. Glycogen synthesis b. Fatty acid synthesis c. Ketone body synthesis d. Ketone body oxidation e. Triglyceride synthesis from fatty acids

E Cunningham Ch 32

``` Lower esophageal achalasia is secondary to damage of: A. Myenteric plexus B. Lower esophageal sphincter C. Cranial nerve X D. Meissner’s plexus ```

A. The myenteric plexus aka auerbach's plexus is located in between the longitudinal and circular muscle layers and control movement through the entire GIT. The submucosal aka meissner's plexus controls local secretion and blood flow Ref: Guyton p 843

Which cell type acts as the electrical pacemaker for the smooth muscle of the gastrointestinal tract? a. Epithelial cells of Cajal b. Enteric nervous plexus c. Enteric purkinje fibers d. Interstitial cells of Cajal

d. Interstitial cells of Cajal

The functions of the GI tract are mainly controlled by: a. The central nervous system. b. The enteric nervous system. c. The endocrine system. d. The enterochromaffin system. e. The hormonal and central nervous systems.

B Cunningham Ch.27

In the small intestine, sodium is mainly reabsorbed in the APICAL border of epithelial cells by which protein? a) Na+/K+ ATPase pump b) Na+ and substrate co-transporters c) Na+ leak channel d) Na+/Cl- antiporter

B. Na and substrate co-transporters ie. aa, glucose vs the basolateral membranes in which Na/K pump regulates Na transport. Source: Guyton ed 13, Ch 66, page 838

``` How long does it take for aldosterone to take effect and increase sodium absorption in the intestine? A. 1-3 hours B. 3-6 hours C. 6-9 hours D. 9-12 hours ```

Answer A. 1-3 hours Cl and H2O follow Na Guyton Pg 839

At the level of the salivary gland, what happens with the following ions? A. Sodium is passively absorbed, chloride is actively absorbed, potassium is actively secreted, and bicarbonate is secreted. B. Sodium is actively secreted, chloride is passively secreted, potassium is actively absorbed, and bicarbonate is secreted. C. Sodium is actively absorbed, chloride is passively absorbed, potassium is actively secreted, and bicarbonate is secreted. D. Sodium is actively secreted, chloride is passively secreted, potassium is passively secreted, and bicarbonate is absorbed.

C. Sodium is actively absorbed, chloride is passively absorbed, potassium is actively secreted, and bicarbonate is secreted.

The term cephalic phase is used in reference to a number of activities occurring in the GI tract. In general, the term means: a. The early phases of digestion, when food is nearest the head. b. Any actions stimulated directly by the presence of food in the stomach. c. Any actions stimulated directly by the presence of food in the mouth. d. Digestive events stimulated by the presence of food in the GI tract, but requiring reflexes integrated in the CNS e. Digestive events that occur before the ingestion of food and in response to central nervous system stimulation that is brought on by the anticipation of eating.

E Cunningham Ch. 28

``` Which of the following does not play a role in regulating pancreatic secretions? A. Secretin B. CCK C. Ach D. Pepsinogen ```

D. Pepsinogen (stimulates acid secretion in the stomach) Secretin - stimulates bicarb secretion by pancreas in response to acid in SI CCK - stimulate bicarb and pancreatic enzyme in response to food in SI Ach - excitatory neurotransmitter Guyton 13th ed. p 826

At which site in the gastrointestinal tract do peptic ulcers most commonly occur? a. Lesser curvature b. Greater curvature c. Gastric cardia d. Pylorus

Answer: D. Reference: Guyton Ch. 67 Pg. 844; Fig 67-1

Which of the following is an important action of cholecystokinin? a. Inhibit gastric acid secretion b. Mucosal growth c. Intestinal motility d. Stimulate pancreatic enzyme secretion

d. Stimulate pancreatic enzyme secretion

In monogastric animals, saliva produced during periods of rapid secretion has a higher electrolyte concentration than saliva produced during periods of slow salivary secretion. From your understanding of salivary gland physiology, which appears to be the most likely explanation? a. During periods of slow salivary secretion, the acinar cells are inactive, and low-electrolyte saliva is secreted by the duct cells. b. Parasympathetic stimulation of the acinar cells results in the elaboration of a more electrolyte-rich saliva. c. Gastrin stimulation increases the electrolyte concentration of saliva. d. During rapid secretion, fluid produced by the acinar cells is exposed to the actions of the duct cells for a shorter time than during slow rates of secretion. e. Different cell types within the acinus are responsible for salivary production, depending on the type of stimulus.

D Cunningham Ch. 29

``` Which of the following factors inhibit gastric emptying by initiating enterogastric inhibitory reflexes ? a. Increased pH of the chyme b. Irritation of the duodenal mucosa c. Stretching of the stomach wall d. Decreased filling of the duodenum ```

Answer : b | Guyton (12th ed.) p. 767

The arrangement of smooth muscle fibers in the muscular layer of the intestinal wall is best described as: a. inner longitudinal and outer circular smooth muscle layers b. inner circular and outer longitudinal smooth muscle layers c. single layer of circular smooth muscle d. two layers of circular smooth muscle, separated by a nerve plexus

b. inner circular and outer longitudinal smooth muscle layers

Small intestinal motility is inhibited by which hormone? a. Secretin b. Motilin c. CCK d. Serotonin

a. Secretin

``` The pathophysiologic basis of which of the following conditions is associated with damage to the myenteric plexus? A. Pancreatitis B. Achlasia C. Achlorydia D. Gastritis ```

B. Achalasia is a condition in which the lower esophageal sphincter fails to relax during swallowing. Pathophysiological studies have shown damage in the neural network of the myenteric plexus of the lower two thirds of the esophagus, which causes spasticity of the musculature of the lower esophagus. As a result, the lower portion of the esophagus fails to undergo receptive relaxation as the bolus of food approaches this area after swallowing. pp. 845-846

``` In achalasia, damage to which structure in the lower esophagus results in failure of the gastroesophageal sphincter to relax during swallowing ? A. Myenteric plexus B. Submucosal plexus C. Esophageal mucosa D. Esophageal musculature ```

Answer A Guyton (12th ed.) p. 799

During sodium absorption by glucose co-transport: a. Chloride is absorbed by the paracellular route. b. Chloride absorption is not affected. c. Chloride is absorbed in exchange for bicarbonate. d. Chloride absorption is coupled with potassium absorption. e. Chloride is absorbed in exchange for hydrogen ion

A Cunningham Ch 30

Entry of food into the small intestine leads to secretion of which of the following substances important for stimulating pancreatic secretion? a. Cholecystokinin b. Vasoactive intestinal peptide c. Acetylcholine d. Secretin

a. Cholecystokinin

Rate of digestion is dependent upon which one of the following? a. Total surface area available to digestive enzymes b. Increased sympathetic nervous system stimulation c. Total volume of bile secreted into the proximal duodenum d. Diameter of the pyloric sphincter

a. Total surface area available to digestive enzymes

From luminal to serosal layers, which of the following is the appropriate order in which the layers of the gastointestinal tract occur? A. Epithelium --> mucosa --> mucosal muscle --> sub mucosa --> longitudinal muscle -> circular muscle -> serosa B. Mucosa --> epithelium --> mucosal muscle --> sub mucosa --> circular muscle -> longitudinal muscle -> serosa C. Epithelium --> mucosa --> submucosa --> mucosal muscle --> circular muscle -> longitudinal muscle -> serosa D. Epithelium --> mucosa --> mucosal muscle --> sub mucosa --> circular muscle -> longitudinal muscle -> serosa

D. Epithelium --> mucosa --> mucosal muscle --> sub mucosa --> circular muscle -> longitudinal muscle -> serosa