PNB 2265 - UNIT 8 EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026
Cephalic Phase - Answers Head and esophagus, responsible for mastication and release of salivary
amylase and lipase
Saliva - Answers Produced by parotid, sublingual and submandibular glands
Acinar cells (salivary) - Answers Produce and secrete saliva into ducts
Saliva composition - Answers Contains fluoride (enamel strength), lysozymes (antibacterial) and
bicarbonate (acid neutralization)
Saliva function - Answers Begins digestion of carbs, lubricates food and digests lipids (infants)
Bolus - Answers Chewed food and saliva
Swallowing (oral phase) - Answers Tongue pushes bolus on soft palate, triggers swallow reflex
Swallowing (pharyngeal phase) - Answers UES relaxes, epiglottis moves to cover trachea
Swallowing (esophageal phase) - Answers Peristalsis moves bolus down esophagus
Upper esophageal sphincter (UES) - Answers Skeletal muscle, voluntary control
Lower esophageal sphincter - Answers Smooth muscle, involuntary control, stays close to prevent
reflux
Esophagus - Answers GI structure between mouth and stomach
Achalasia - Answers Pressure within LES region is too high, bolus is harder to move into the stomach
Gastroesophageal reflux disease (GERD) - Answers LES failure leads to reflux of stomach acid and
contents
GERD contributing factors - Answers Chocolate, caffeine, alcohol and cigarettes can
worsen/contribute to GERD
Gastric phase - Answers Events occurring in the stomach when food enters
Regions of the stomach - Answers From esophagus to duodenum: cardia, fundus, body, pyloric
antrum, pyloric canal
Proximal stomach - Answers Acts as a food reservoir, contains the cardia, fundus and body
Distal stomach - Answers Functions to grind/pump food, contains pyloric antrum and pyloric
sphincter
Rugae - Answers Stomach folds, allow expansion and increase surface area
Oblique muscle layer - Answers Mixes chyme in the distal stomach
Cardia role - Answers Secretes mucus and bicarbonate
Fundus and body role - Answers Secretes H+, intrinsic factor, mucus, bicarbonate, pepsinogen, lipase,
maintains gentle pressure to move food
Antrum and pylorus role - Answers Secretes mucus and bicarbonate, mixes/grinds/controls emptying
Parietal cells - Answers Produce stomach acid and intrinsic factor
Chief cells - Answers Produce pepsinogen and gastric lipase
Pepsinogen - Answers Endopeptidase, activated into pepsin by HCl
G cells - Answers Produce gastrin
Gastrin - Answers Stimulates HCl production, increases Ca, which increases PKC leading to acid
production
D cells - Answers Produce somatostatin in response to low (acidic) pH
Somatostatin - Answers Slows down acid production, lowers cAMP and inhibits the proton pump,
decreases gastrin/histamine release
Enterochromaffin like cells (ECL cells) - Answers Release histamine, stimulating acid production,
increases cAMP leading to higher PKA, and higher acid
Mucous neck cells - Answers produce mucous and bicarbonate, protect stomach lining
H/K ATPase - Answers Located on parietal cells, secretes H+ into the stomach
Acetylcholine (ACh) - Answers PNS activator, increases Ca, PKC and then acid
Parasympathetic nervous system (PNS) control - Answers Controls motility, secretion and relaxation
Receptive relaxation - Answers Stretch receptors sense esophageal stretching, inhibit stomach
muscles, relaxing them
Adaptive relaxation - Answers Stretch receptors sense stomach stretching, inhibit stomach muscle,
relaxing them
Vasovagal reflex - Answers Reflex triggered by stomach distension and chemical stimuli from
nutrients, mediated by vagus nerve, integrates neural control during gastric phase to optimize
digestion
Cephalic Phase - Answers Head and esophagus, responsible for mastication and release of salivary
amylase and lipase
Saliva - Answers Produced by parotid, sublingual and submandibular glands
Acinar cells (salivary) - Answers Produce and secrete saliva into ducts
Saliva composition - Answers Contains fluoride (enamel strength), lysozymes (antibacterial) and
bicarbonate (acid neutralization)
Saliva function - Answers Begins digestion of carbs, lubricates food and digests lipids (infants)
Bolus - Answers Chewed food and saliva
Swallowing (oral phase) - Answers Tongue pushes bolus on soft palate, triggers swallow reflex
Swallowing (pharyngeal phase) - Answers UES relaxes, epiglottis moves to cover trachea
Swallowing (esophageal phase) - Answers Peristalsis moves bolus down esophagus
Upper esophageal sphincter (UES) - Answers Skeletal muscle, voluntary control
Lower esophageal sphincter - Answers Smooth muscle, involuntary control, stays close to prevent
reflux
Esophagus - Answers GI structure between mouth and stomach
Achalasia - Answers Pressure within LES region is too high, bolus is harder to move into the stomach
Gastroesophageal reflux disease (GERD) - Answers LES failure leads to reflux of stomach acid and
contents
GERD contributing factors - Answers Chocolate, caffeine, alcohol and cigarettes can
worsen/contribute to GERD
Gastric phase - Answers Events occurring in the stomach when food enters
Regions of the stomach - Answers From esophagus to duodenum: cardia, fundus, body, pyloric
antrum, pyloric canal
Proximal stomach - Answers Acts as a food reservoir, contains the cardia, fundus and body
Distal stomach - Answers Functions to grind/pump food, contains pyloric antrum and pyloric
sphincter
Rugae - Answers Stomach folds, allow expansion and increase surface area
Oblique muscle layer - Answers Mixes chyme in the distal stomach
Cardia role - Answers Secretes mucus and bicarbonate
Fundus and body role - Answers Secretes H+, intrinsic factor, mucus, bicarbonate, pepsinogen, lipase,
maintains gentle pressure to move food
Antrum and pylorus role - Answers Secretes mucus and bicarbonate, mixes/grinds/controls emptying
Parietal cells - Answers Produce stomach acid and intrinsic factor
Chief cells - Answers Produce pepsinogen and gastric lipase
Pepsinogen - Answers Endopeptidase, activated into pepsin by HCl
G cells - Answers Produce gastrin
Gastrin - Answers Stimulates HCl production, increases Ca, which increases PKC leading to acid
production
D cells - Answers Produce somatostatin in response to low (acidic) pH
Somatostatin - Answers Slows down acid production, lowers cAMP and inhibits the proton pump,
decreases gastrin/histamine release
Enterochromaffin like cells (ECL cells) - Answers Release histamine, stimulating acid production,
increases cAMP leading to higher PKA, and higher acid
Mucous neck cells - Answers produce mucous and bicarbonate, protect stomach lining
H/K ATPase - Answers Located on parietal cells, secretes H+ into the stomach
Acetylcholine (ACh) - Answers PNS activator, increases Ca, PKC and then acid
Parasympathetic nervous system (PNS) control - Answers Controls motility, secretion and relaxation
Receptive relaxation - Answers Stretch receptors sense esophageal stretching, inhibit stomach
muscles, relaxing them
Adaptive relaxation - Answers Stretch receptors sense stomach stretching, inhibit stomach muscle,
relaxing them
Vasovagal reflex - Answers Reflex triggered by stomach distension and chemical stimuli from
nutrients, mediated by vagus nerve, integrates neural control during gastric phase to optimize
digestion
