OSSF INSTALLER 1 LICENSE EXAM QUESTIONS AND
CORRECT ANSWERS| ACCURATE REAL EXAM WITH
FREQUENTLY TESTED QUESTIONS AND
RATIONALE|ALREADY A GRADED|GUARANTEED
PASS|LATEST UPDATE 2025.
Classification based on Food Source - CORRECT ANSWER Herbivores (browsers, grazers,
intermediate feeders)
Carnivores
Omnivores
Classification Based on Stomach Type - CORRECT ANSWER Monogastric
Ruminant
4 Functions Layers of Intestinal Wall - CORRECT ANSWER 1. One cell separating lumen from
bloodstream (small intestine)
2. Circular and longitudinal muscle
3. Myenteric and submucosal plexuses
4. Villi and microvilli
Countercurrent Effects on Intestinal Villi - CORRECT ANSWER Hypoxic at intestinal villus tip
due to structure and high metabolic activity
O2 is lost into venous blood
Blood Flow to and from digestive tract - CORRECT ANSWER Intestines, pancreas, spleen
drain via hepatic portal v into liver
Liver drains via hepatic veins to inferior vena cava (receives more blood from portal circulation
than hepatic a)
3 Phases of Digestion - CORRECT ANSWER 1. Cephalic: sight/thought/smell stimulate
cerebral cortex
2. Gastric: digestion when food enters stomach
3. Intestinal phase: digestion in duodenum
3 Control Systems of GI function - CORRECT ANSWER 1. Endocrine
2. Paracrine
3. Neuocrine
Neurotransmitters for PNS/SNS - CORRECT ANSWER ACh (cholingeric): somatic motor and
all preganglionic
PNS: Ach and enteric peptides
SNS: GI tracts uses NE (adrenergic)
Name 4 Enteric Peptides used as Neurotransmitters - CORRECT ANSWER 1. substance P
2. VIP
,3. Neuropeptide Y
4. GRP
PNS/SNS Receptor Types - CORRECT ANSWER PNS: pre = nicotinic. post = muscarinic
SNS: pre = nicotinic. post = alpha and beta
Enteric Nervous System - CORRECT ANSWER Submucosal (Meissner) and myenteric
(Auerbach)
Communicate with CNS via vagal, pelvic and splanchnic nn
Draw good overall conceptual slide of enteric nervous system - CORRECT ANSWER Lecture
2. Slide 20
Extrinsic vs Intrinsic Reflexes govern GI Function - CORRECT ANSWER Extrinsic (long):
stimuli from body goes to CNS
Intrinsic (short): stimuli from lumen goes directly to wall of GI
Dominating regulation for salivary glands, stomach, pancreas, SI, LI - CORRECT ANSWER
PNS
Even
Hormonal, PNS
Local reflexes, PNS
PNS, local reflexes
What makes a GI Hormone? - CORRECT ANSWER Found in GI endocrine cells
Physiological stimuli
Circulate in blood (works w/o nervous system)
3 Main GI Hormone Families - CORRECT ANSWER 1. Gastrin-CKK Family
2. Secretin-Glucagon Family (GIP)
3. Motilin
Gastrin secretion, stim, inhib - CORRECT ANSWER Secreted by G cells in antrum of stomach
Stim: protein, distension of stomach, nerve stimulation (vagal) of G cells
Inhib: acid
Effects of Gastrin 3 - CORRECT ANSWER Primary: stimulate acid secretion
Mucosal growth
Gastric motility
Zollinger-Ellis Syndrome - CORRECT ANSWER Tumor that secretes gastrin
Decrease pH and overgrown mucosa
CCK secretion, stim - CORRECT ANSWER Secretion: I cells of duodenal and jejunal
Stim: Monoglycerides, FA, protein
,CCK functions - CORRECT ANSWER Promote pancreatic bicarb and enzyme secretion
Promote gallbladder contraction
Inhibit gastric emptying
Synergistic with Secretin for increase in pancreatic enzymes
Secretin secretion, stim - CORRECT ANSWER S cells in duodenum
Stim: gastric acid** (pH < 4.5)
FA, proteins, BA
Secretin Functions - CORRECT ANSWER Pancreatic and biliary bicarb and water secretion
Inhibit gastric acid secretion
Stim insulin release
Pancreatic growth
Synergistic with CCK -> pancreatic enzyme secretion
GIP secreiton, stim - CORRECT ANSWER K cells in duodenum and jejunum
Stim: protein, fat, CHO
GIP Functions - CORRECT ANSWER 1. Inhibit gastric acid
2. Inhibit gastric emptying. Stimulate insulin release
Motilin secretion, stim - CORRECT ANSWER M cells of duodenum and jejunum
Vagal stimulation during interdigestive periods
Motilin Function - CORRECT ANSWER Increase GI motility
Initiate interdigestive migrating motility complex
Functions of Motility or Absence of Motility - CORRECT ANSWER 1. Propulsion. Peristalsis
vs antiperistalsis
2. Mixing
3. No motility - act as reservoir (stomach, gallbladder, colon)
Methods of Controlling Motility - CORRECT ANSWER 1. Myogenic: skeletal muscles and
visceral smooth muscle
2. Neurogenic: Intrinsic and extrinsicv
3. Endocrine
4. Paracrine
Basal Electrical Rhythm (BER) - CORRECT ANSWER Aborally moving waves of partial
depolarization. Neuronal/hormonal signal pushes past threwhold -> contraction
Governed by interstitial cells of Cajal (ICC): smooth muscle pacemaker cells
Deglutition Phases - CORRECT ANSWER 1. Oral: tongue forces bolus towards pharynx.
Involuntary swallowing reflex in medulla
2. Pharyngeal: bolus from mouth to pharynx to esophagus
3. Esophageal: primary and secondary peristaltic wave
, Swallowing Reflex - CORRECT ANSWER Carried to medullary swallowing center via vagus
and glosopharyngeal nerves
Nucleus ambiguus activates striated muscle
Dorsal motor nucleus activates smooth muscle
Primary vs Secondary Peristalsis - CORRECT ANSWER 1. Swallowing
2. Clearing remaining material from esophagus or from reflux
UES or LES is major site of regulation? - CORRECT ANSWER LES. Neural and hormonal
influences
Salivary Glands and type of secretion - CORRECT ANSWER Parotid: serous
Sublingual: mixed
Mandibular: mixed
Zygomatic: mucous
7 Functions of Saliva - CORRECT ANSWER 1. Hydration
2. Evaporative cooling
3. Bicarb and Phosphate for buffering
4. R factor for vit B12 transport
5. Protection from bacterai
6. Initial food digestion (amaylase and lipase)
7. Urea
Saliva Protection from Bacteria 5 - CORRECT ANSWER 1. HCO and other buffers
2. IgA
3. Lysozyme
4. Proline-rich proteins bind to tannins
5. Lactoferrin binds Fe++ and is bacteriostatic
Salivon - CORRECT ANSWER Basic functional unit of salivary secretion
Primary secretion by acinar cells. Stimulated by myoepithelial cells
Striated ducts modify saliva electrolyte concentrations
2 Step process of Saliva Modification - CORRECT ANSWER Originally isotonic, similar to
plasma
Na, Cl reabsorption (greater)
K, HCO3 secretion
Hypotonic
Flow rate Effect on Ionic Composition of Saliva - CORRECT ANSWER Slow: more contact
with ductal cells, more reabsorption/secretion
Fast: similar to initial secretion values
CORRECT ANSWERS| ACCURATE REAL EXAM WITH
FREQUENTLY TESTED QUESTIONS AND
RATIONALE|ALREADY A GRADED|GUARANTEED
PASS|LATEST UPDATE 2025.
Classification based on Food Source - CORRECT ANSWER Herbivores (browsers, grazers,
intermediate feeders)
Carnivores
Omnivores
Classification Based on Stomach Type - CORRECT ANSWER Monogastric
Ruminant
4 Functions Layers of Intestinal Wall - CORRECT ANSWER 1. One cell separating lumen from
bloodstream (small intestine)
2. Circular and longitudinal muscle
3. Myenteric and submucosal plexuses
4. Villi and microvilli
Countercurrent Effects on Intestinal Villi - CORRECT ANSWER Hypoxic at intestinal villus tip
due to structure and high metabolic activity
O2 is lost into venous blood
Blood Flow to and from digestive tract - CORRECT ANSWER Intestines, pancreas, spleen
drain via hepatic portal v into liver
Liver drains via hepatic veins to inferior vena cava (receives more blood from portal circulation
than hepatic a)
3 Phases of Digestion - CORRECT ANSWER 1. Cephalic: sight/thought/smell stimulate
cerebral cortex
2. Gastric: digestion when food enters stomach
3. Intestinal phase: digestion in duodenum
3 Control Systems of GI function - CORRECT ANSWER 1. Endocrine
2. Paracrine
3. Neuocrine
Neurotransmitters for PNS/SNS - CORRECT ANSWER ACh (cholingeric): somatic motor and
all preganglionic
PNS: Ach and enteric peptides
SNS: GI tracts uses NE (adrenergic)
Name 4 Enteric Peptides used as Neurotransmitters - CORRECT ANSWER 1. substance P
2. VIP
,3. Neuropeptide Y
4. GRP
PNS/SNS Receptor Types - CORRECT ANSWER PNS: pre = nicotinic. post = muscarinic
SNS: pre = nicotinic. post = alpha and beta
Enteric Nervous System - CORRECT ANSWER Submucosal (Meissner) and myenteric
(Auerbach)
Communicate with CNS via vagal, pelvic and splanchnic nn
Draw good overall conceptual slide of enteric nervous system - CORRECT ANSWER Lecture
2. Slide 20
Extrinsic vs Intrinsic Reflexes govern GI Function - CORRECT ANSWER Extrinsic (long):
stimuli from body goes to CNS
Intrinsic (short): stimuli from lumen goes directly to wall of GI
Dominating regulation for salivary glands, stomach, pancreas, SI, LI - CORRECT ANSWER
PNS
Even
Hormonal, PNS
Local reflexes, PNS
PNS, local reflexes
What makes a GI Hormone? - CORRECT ANSWER Found in GI endocrine cells
Physiological stimuli
Circulate in blood (works w/o nervous system)
3 Main GI Hormone Families - CORRECT ANSWER 1. Gastrin-CKK Family
2. Secretin-Glucagon Family (GIP)
3. Motilin
Gastrin secretion, stim, inhib - CORRECT ANSWER Secreted by G cells in antrum of stomach
Stim: protein, distension of stomach, nerve stimulation (vagal) of G cells
Inhib: acid
Effects of Gastrin 3 - CORRECT ANSWER Primary: stimulate acid secretion
Mucosal growth
Gastric motility
Zollinger-Ellis Syndrome - CORRECT ANSWER Tumor that secretes gastrin
Decrease pH and overgrown mucosa
CCK secretion, stim - CORRECT ANSWER Secretion: I cells of duodenal and jejunal
Stim: Monoglycerides, FA, protein
,CCK functions - CORRECT ANSWER Promote pancreatic bicarb and enzyme secretion
Promote gallbladder contraction
Inhibit gastric emptying
Synergistic with Secretin for increase in pancreatic enzymes
Secretin secretion, stim - CORRECT ANSWER S cells in duodenum
Stim: gastric acid** (pH < 4.5)
FA, proteins, BA
Secretin Functions - CORRECT ANSWER Pancreatic and biliary bicarb and water secretion
Inhibit gastric acid secretion
Stim insulin release
Pancreatic growth
Synergistic with CCK -> pancreatic enzyme secretion
GIP secreiton, stim - CORRECT ANSWER K cells in duodenum and jejunum
Stim: protein, fat, CHO
GIP Functions - CORRECT ANSWER 1. Inhibit gastric acid
2. Inhibit gastric emptying. Stimulate insulin release
Motilin secretion, stim - CORRECT ANSWER M cells of duodenum and jejunum
Vagal stimulation during interdigestive periods
Motilin Function - CORRECT ANSWER Increase GI motility
Initiate interdigestive migrating motility complex
Functions of Motility or Absence of Motility - CORRECT ANSWER 1. Propulsion. Peristalsis
vs antiperistalsis
2. Mixing
3. No motility - act as reservoir (stomach, gallbladder, colon)
Methods of Controlling Motility - CORRECT ANSWER 1. Myogenic: skeletal muscles and
visceral smooth muscle
2. Neurogenic: Intrinsic and extrinsicv
3. Endocrine
4. Paracrine
Basal Electrical Rhythm (BER) - CORRECT ANSWER Aborally moving waves of partial
depolarization. Neuronal/hormonal signal pushes past threwhold -> contraction
Governed by interstitial cells of Cajal (ICC): smooth muscle pacemaker cells
Deglutition Phases - CORRECT ANSWER 1. Oral: tongue forces bolus towards pharynx.
Involuntary swallowing reflex in medulla
2. Pharyngeal: bolus from mouth to pharynx to esophagus
3. Esophageal: primary and secondary peristaltic wave
, Swallowing Reflex - CORRECT ANSWER Carried to medullary swallowing center via vagus
and glosopharyngeal nerves
Nucleus ambiguus activates striated muscle
Dorsal motor nucleus activates smooth muscle
Primary vs Secondary Peristalsis - CORRECT ANSWER 1. Swallowing
2. Clearing remaining material from esophagus or from reflux
UES or LES is major site of regulation? - CORRECT ANSWER LES. Neural and hormonal
influences
Salivary Glands and type of secretion - CORRECT ANSWER Parotid: serous
Sublingual: mixed
Mandibular: mixed
Zygomatic: mucous
7 Functions of Saliva - CORRECT ANSWER 1. Hydration
2. Evaporative cooling
3. Bicarb and Phosphate for buffering
4. R factor for vit B12 transport
5. Protection from bacterai
6. Initial food digestion (amaylase and lipase)
7. Urea
Saliva Protection from Bacteria 5 - CORRECT ANSWER 1. HCO and other buffers
2. IgA
3. Lysozyme
4. Proline-rich proteins bind to tannins
5. Lactoferrin binds Fe++ and is bacteriostatic
Salivon - CORRECT ANSWER Basic functional unit of salivary secretion
Primary secretion by acinar cells. Stimulated by myoepithelial cells
Striated ducts modify saliva electrolyte concentrations
2 Step process of Saliva Modification - CORRECT ANSWER Originally isotonic, similar to
plasma
Na, Cl reabsorption (greater)
K, HCO3 secretion
Hypotonic
Flow rate Effect on Ionic Composition of Saliva - CORRECT ANSWER Slow: more contact
with ductal cells, more reabsorption/secretion
Fast: similar to initial secretion values
