70 clinical MCQs in GIT Physiology. Which single statement below, about the stomach, is correct? —. Kenya, Africa and global revision.
-
Q1. Which single statement below, about the stomach, is correct? ---
- Acid secretion occurs in response to secretion of the hormone, carbonic anhydrase
- Glands called Peyer's patches are responsible for acid secretion
- The vagus nerve inhibits acid secretion after a meal has been consumed
- Pepsinogen and gastric lipase are secreted into the lumen of the stomach
- Primarily an incidental laboratory finding
Answer: Acid secretion occurs in response to secretion of the hormone, carbonic anhydrase
-
Q2. Water transport can occur from the lumen of the intestine to the bloodstream, or vice versa. Which statement is correct? ---
- A "flip-flop" mechanism efficiently transports water directly across the enterocyte membrane
- Water flows into the gut from the mucosa during digestion of starch and protein to reduce luminal osmolality
- Water is mostly absorbed by movement between enterocytes via tight junctions
- Dietary intake of water is always greater than water movement in the small intestine
- Usually mediated by non-specific mechanisms
Answer: A "flip-flop" mechanism efficiently transports water directly across the enterocyte membrane
-
Q3. Which statement about fat digestion and absorption is correct? ---
- Fatty acids are absorbed mainly via FABP and FAT/CD36 in the distal duodenum
- Medium-chain triglycerides (MCT) enter lymphatics; long-chain triglycerides enter portal blood
- Partial digestion products form mixed micelles with cholesterol/phospholipids, enhancing absorption
- Triglycerides must be emulsified and digested before fatty acids are transported
- Mostly unchanged in early disease
Answer: Fatty acids are absorbed mainly via FABP and FAT/CD36 in the distal duodenum
-
Q4. Which statement about protein digestion is most correct? ---
- Products of protein digestion are absorbed as free amino acids or di-/tripeptides
- Gastric digestion of all proteins is equally efficient due to antral grinding
- Chief cells secrete chymotrypsin, elastase, and carboxypeptidase A
- Only one of 14 amino acid transporters absorbs digested protein products
- Reduced by routine feedback control
Answer: Products of protein digestion are absorbed as free amino acids or di-/tripeptides
-
Q5. Which statement about dietary fibre is most correct? ---
- Fermentation end products are mainly malic, succinic, and propionic acids
- Soluble/insoluble fibres are completely fermented within 24 hours in vitro
- Fiber sources such as Hemicelluloses, pectins, and inulin ferment rapidly to SCFAs with trophic colon effects
- Stool bulking occurs mainly via insoluble fibres like cellulose
- Occurs only after chronic exposure
Answer: Fermentation end products are mainly malic, succinic, and propionic acids
-
Q6. Which statement about absorption is most correct? ---
- Glucose absorption is associated with sodium uptake
- Fructose is absorbed more rapidly than glucose
- Galactose and fructose share the same brush-border transporter
- Most water absorption occurs in the colon
- Limited to a single tissue compartment
Answer: Glucose absorption is associated with sodium uptake
-
Q7. Which statement about the oral phase of digestion is INCORRECT? ---
- ~2% of food energy is expended in chewing/swallowing
- Swallowing involves 14 muscle groups over ~10 seconds in healthy subjects
- Tooth enamel biofilm contains salivary/bacterial enzymes
- Salivary amylase digests dextran film from dietary sucrose
- Primarily an incidental laboratory finding
Answer: ~2% of food energy is expended in chewing/swallowing
-
Q8. Which statement about stomach lining cells is correct? ---
- Mucous cells secrete the glycoprotein mucin
- Chief cells secrete the hormone gastrin
- Parietal cells secrete pepsinogen
- G Cells secrete hydrochloric acid
- Usually mediated by non-specific mechanisms
Answer: Mucous cells secrete the glycoprotein mucin
-
Q9. Which statement about pancreatic enzyme secretion is correct? ---
- Pepsinogen is the chief protein-digesting enzyme
- Pancreatic α-amylase hydrolyzes starch to free glucose
- Enteropeptidase converts trypsinogen to trypsin by cleaving an inhibitory peptide
- Pancreatic HCl secretion is required for duodenal enzyme pH
- Mostly unchanged in early disease
Answer: Pepsinogen is the chief protein-digesting enzyme
-
Q10. Which statement about post-meal motility is correct? ---
- Migrating motor complex drives peristalsis after a meal
- Insulin slows gastric emptying
- Stomach increases tone at meal start to expel contents via pylorus
- Partially digested fat/starch in the duodenum slows intestinal motility
- Reduced by routine feedback control
Answer: Migrating motor complex drives peristalsis after a meal
-
Q11. Which best describes colonic microbiota functions? ---
- Daily fibre intake underestimates fermentable material in the colon
- All of the options given are correct
- Acetate, propionate, butyrate are main SCFAs from fermentation
- Acetate buffer suppresses pathogenic bacteria growth
- Occurs only after chronic exposure
Answer: Daily fibre intake underestimates fermentable material in the colon
-
Q12. What explains fibre's protective effect against colon cancer? ---
- Propionic acid inhibits liver fatty acid synthesis
- Butyric acid silences the SLC5A8 tumor suppressor gene
- None of these options are correct
- Butyric acid stimulates colon antioxidant defenses
- Limited to a single tissue compartment
Answer: Propionic acid inhibits liver fatty acid synthesis
-
Q13. Which best describes vitamin absorption? ---
- All of the options given are correct
- Vitamin E is absorbed by a peroxidized fatty acid-binding protein
- Thiamine pyrophosphate must be dephosphorylated for absorption
- Dehydroascorbic acid (oxidized vitamin
- uses a glucose transporter
Answer: All of the options given are correct
-
Q14. Which best describes the intestine's role in obesity? ---
- Obesity results from deranged gut hormones (e.g., low PYY)
- Gut/brain signaling controls energy intake within 2% even in morbid obesity
- Gluttony overrides strong satiety signals regularly
- Processed food flavors override satiety post-meal
- Usually mediated by non-specific mechanisms
Answer: Obesity results from deranged gut hormones (e.g., low PYY)
-
Q15. Which is true about pancreatic secretions vs. plasma? ---
- Higher secretion rate increases bicarbonate/sodium; plasma has less bicarbonate
- Higher secretion increases bicarbonate but decreases chloride
- Higher secretion increases osmolarity/pH; plasma is lower
- Higher secretion increases bicarbonate/potassium; plasma has lower levels
- Mostly unchanged in early disease
Answer: Higher secretion rate increases bicarbonate/sodium; plasma has less bicarbonate
-
Q16. Which has little effect on pancreatic secretion? ---
- Acetylcholine
- Sympathetic stimulation
- Secretin
- Cholecystokinin
- Reduced by routine feedback control
Answer: Acetylcholine
-
Q17. Defective parietal cells cause malabsorption of which vitamin? ---
- Vitamin B1
- Vitamin B2
- Vitamin B13
- Vitamin B12
- Occurs only after chronic exposure
Answer: Vitamin B1
-
Q18. Which is absorbed by passive diffusion via concentration gradient? ---
- Sodium
- Potassium
- Calcium
- Phosphate
- Limited to a single tissue compartment
Answer: Sodium
-
Q19. How much of the ~9L daily GI tract water exits in feces? ---
- 100 ml
- 1000 ml
- 1500 ml
- 500 ml
- Primarily an incidental laboratory finding
Answer: 100 ml
-
Q20. Saliva contains which carbohydrate-digesting enzyme? ---
- Pepsin
- Amylase
- Trypsin
- Lipase
- Usually mediated by non-specific mechanisms
Answer: Pepsin
-
Q21. Proteins are primarily digested to and absorbed as ---
- Amino acids
- Glycerides
- Nucleic acids
- Fatty acids
- Mostly unchanged in early disease
Answer: Amino acids
-
Q22. The major chemical digestive activity in the stomach is ---
- Starch breakdown
- Protein breakdown
- Fat breakdown
- Fibre breakdown
- Reduced by routine feedback control
Answer: Starch breakdown
-
Q23. Which is true about pancreatic secretions? ---
- CCK causes bicarbonate release
- Secretin causes enzyme release
- Gastrin stimulates enzyme release
- CCK stimulates enzyme release
- Occurs only after chronic exposure
Answer: CCK causes bicarbonate release
-
Q24. The hormone that inhibits gastric secretion and motility is ---
- Gastrin
- Histamine
- Secretin
- Pepsin
- Limited to a single tissue compartment
Answer: Gastrin
-
Q25. How are fat components absorbed in the small intestine? ---
- Receptor proteins carry fatty acids to bloodstream
- Fatty acids are actively transported
- Lipid components diffuse through enterocyte membranes
- Lipid components diffuse directly into liver bloodstream
- Primarily an incidental laboratory finding
Answer: Receptor proteins carry fatty acids to bloodstream
-
Q26. Which is a water-soluble vitamin? ---
- Vitamin D
- Vitamin C
- Vitamin E
- Vitamin K
- Usually mediated by non-specific mechanisms
Answer: Vitamin D
-
Q27. How long for food to pass completely through the large intestine? ---
- 10 minutes
- 1 hour
- 5 hours
- 20 hours
- Mostly unchanged in early disease
Answer: 10 minutes
-
Q28. Citric acid cycle is part of what metabolic pathway? ---
- Amphibolic
- Anabolic
- Catabolic
- None of the above
- Reduced by routine feedback control
Answer: Amphibolic
-
Q29. What is the amount of protein lost as obligatory loss? ---
- 10–20 gms
- 50–60 gms
- 20–30 gms
- 60–70 gms
- Occurs only after chronic exposure
Answer: 10–20 gms
-
Q30. Regarding glycolysis, which statement is incorrect? ---
- Principle route of metabolism
- Provides ATP in the absence of oxygen
- Plays a role in metabolism of fructose and maltose
- Plays a role in production of Acetyl CoA in the citric acid cycle
- Limited to a single tissue compartment
Answer: Principle route of metabolism
-
Q31. Deficiency of which vitamin is the main cause of night blindness? ---
- Vitamin A
- Thiamine (Vitamin B1)
- Riboflavin (Vitamin B2)
- Vitamin B12
- Primarily an incidental laboratory finding
Answer: Vitamin A
-
Q32. Deficiency of which vitamin is the main cause of beriberi? ---
- Vitamin A
- Thiamine (Vitamin B1)
- Riboflavin (Vitamin B2)
- Vitamin B12
- Usually mediated by non-specific mechanisms
Answer: Vitamin A
-
Q33. Which of the following would tend to decrease hunger? ---
- Increased release of endorphins
- Increased ghrelin release by the stomach
- Increased release of PYY by the intestine
- Increased release of NPY by the hypothalamus
- Mostly unchanged in early disease
Answer: Increased release of endorphins
-
Q34. Deficiency of which vitamin is most likely to cause impaired blood clotting? ---
- Vitamin A
- Vitamin C
- Vitamin D
- Vitamin K
- Reduced by routine feedback control
Answer: Vitamin A
-
Q35. The first stage in using triglycerides for energy is hydrolysis to which substances? ---
- Acetyl CoA and glycerol
- Cholesterol and fatty acids
- Glycerol 3-phosphate and cholesterol
- Glycerol and fatty acids
- Occurs only after chronic exposure
Answer: Acetyl CoA and glycerol
-
Q36. Which of the following best describes glucose formation from amino acids? ---
- Gluconeogenesis
- Glycogenesis
- Glycogenolysis
- Glycolysis
- Limited to a single tissue compartment
Answer: Gluconeogenesis
-
Q37. The defecation reflex is integrated in the ---
- Brain stem
- Pons
- Medulla
- Spinal cord
- Primarily an incidental laboratory finding
Answer: Brain stem
-
Q38. The CNS includes all the following except ---
- Spinal cord
- Medulla oblongata
- Autonomic ganglia
- Diencephalon
- Usually mediated by non-specific mechanisms
Answer: Spinal cord
-
Q39. The CNS connects with PNS through all except ---
- Postganglionic autonomic fibers
- Preganglionic autonomic fibers
- Somatic motor fibers
- Autonomic sensory fibers
- Mostly unchanged in early disease
Answer: Postganglionic autonomic fibers
-
Q40. Parietal lobe neglect ---
- Inability to use skeletal muscles on opposite side of the body
- Inability to use skeletal muscles on same side of the body
- Results from damage to primary sensory cortex
- Causes loss of sensation on same side
- Reduced by routine feedback control
Answer: Inability to use skeletal muscles on opposite side of the body
-
Q41. All of the following are descending motor tracts, except ---
- Rubrospinal tract
- Spinotectal tract
- Reticulospinal tract
- Corticobulbar tract
- Occurs only after chronic exposure
Answer: Rubrospinal tract
-
Q42. Corticospinal tract originates from all the following, except ---
- Premotor area in frontal lobe
- Prefrontal area in frontal lobe
- Supplemental motor area in frontal lobe
- Somatic sensory area in parietal lobe
- Limited to a single tissue compartment
Answer: Premotor area in frontal lobe
-
Q43. Representation in primary motor area ---
- Is ipsilateral
- Is upright
- Is disproportionate to actual size of body parts
- All the above
- Primarily an incidental laboratory finding
Answer: Is ipsilateral
-
Q44. Primary motor area receives input from all except ---
- Basal ganglia
- Cerebellum
- Hypothalamus
- Thalamus
- Usually mediated by non-specific mechanisms
Answer: Basal ganglia
-
Q45. Primary motor area projects to all the following except ---
- Primary somatic sensory area
- Premotor area
- Supplemental motor area
- Brainstem motor nuclei
- Mostly unchanged in early disease
Answer: Primary somatic sensory area
-
Q46. Premotor area includes all the following except ---
- Broca’s area
- Head rotation area
- Supplemental motor area
- Hand skills area
- Reduced by routine feedback control
Answer: Broca’s area
-
Q47. Supplemental motor area is involved in all the following except ---
- Adjusting posture
- Orienting responses
- Motor programming
- Coordinating bilateral movements
- Occurs only after chronic exposure
Answer: Adjusting posture
-
Q48. Components of the vestibular apparatus include all except ---
- Crista ampullaris
- Vestibular hair cells
- Vestibular nucleus
- Saccule
- Limited to a single tissue compartment
Answer: Crista ampullaris
-
Q49. Crista ampullaris is sensitive to ---
- Sound vibrations
- Force of gravity
- Linear acceleration
- Angular acceleration
- Primarily an incidental laboratory finding
Answer: Sound vibrations
-
Q50. Vestibular hair cells ---
- Have cilia all over surface
- Are innervated by cochlear nerve
- Are stimulated by neurotransmitter from nerve terminals
- Are sensitive to mechanical stimuli
- Usually mediated by non-specific mechanisms
Answer: Have cilia all over surface
-
Q51. Hair cells of cristae are stimulated by ---
- Bending of stereocilia in any direction
- Movement of endolymph in any direction
- Bending of stereocilia toward kinocilium
- Bending away from kinocilium
- Mostly unchanged in early disease
Answer: Bending of stereocilia in any direction
-
Q52. Maculae of vestibular apparatus ---
- Stimulated by endolymph flow
- Stimulated when standing, inhibited lying down
- Alter discharge by head tilt
- Contain otoconia that press on hair cells
- Reduced by routine feedback control
Answer: Stimulated by endolymph flow
-
Q53. Basal ganglia include all except ---
- Caudate nucleus
- Dentate nucleus
- Subthalamic nucleus
- Substantia nigra reticulata
- Occurs only after chronic exposure
Answer: Caudate nucleus
-
Q54. Neurotransmitters in basal ganglia include all except ---
- GABA
- Dopamine
- Glutamate
- Glycine
- Limited to a single tissue compartment
Answer: GABA
-
Q55. Functions of basal ganglia include all except ---
- Scanning
- Initiation of reflex movements
- Postural regulation
- Executing learned movement patterns
- Primarily an incidental laboratory finding
Answer: Scanning
-
Q56. Parkinson’s disease results from damage of ---
- Caudate nucleus
- Subthalamic nucleus
- Globus pallidus
- Substantia nigra
- Usually mediated by non-specific mechanisms
Answer: Caudate nucleus
-
Q57. Manifestations of Parkinsonism include all except ---
- Kinetic tremors
- Rigidity
- Bradykinesia
- Disturbance of speech
- Mostly unchanged in early disease
Answer: Kinetic tremors
-
Q58. Limbic system functions in emotional behavior involve all except ---
- Homeostasis
- Somatic motor responses
- Memory consolidation
- Generalized sympathetic stimulation
- Reduced by routine feedback control
Answer: Homeostasis
-
Q59. Hyperkinetic features in Huntington's disease are due to loss of ---
- Nigrostriatal dopaminergic neurons
- Intrastriatal cholinergic neurons
- GABAergic and dopaminergic neurons
- Intrastriatal GABAergic and cholinergic neurons
- Occurs only after chronic exposure
Answer: Nigrostriatal dopaminergic neurons
-
Q60. Most prominent growth of anterior corpus callosum occurs at ---
- 6–12 months
- 6–15 years
- 3–6 years
- None of the above
- Limited to a single tissue compartment
Answer: 6–12 months
-
Q61. Blood flow to the brain is approximately ---
- 2–3 litres/min
- 2–3 ml/sec
- 700–900 ml/min
- None of the above
- Primarily an incidental laboratory finding
Answer: 2–3 litres/min
-
Q62. Which of the following mechanisms is currently implicated in learning and memory? ---
- Modulation of release of neurotransmitters in postsynaptic neurons
- Modulation of neurotransmitter receptor synthesis
- Formation of new neurons
- Spatial organization of association areas E. All of the above
- Usually mediated by non-specific mechanisms
Answer: Modulation of release of neurotransmitters in postsynaptic neurons
-
Q63. Which statement is false about the basal ganglia? ---
- Basal ganglia are gray matter structures deep within the white matter
- Pathologies result in movement disorders
- The basal ganglia initiate and maintain motor output D. The basal ganglia output is excitatory
- The basal ganglia project to areas involved in motor control and cognition
- Mostly unchanged in early disease
Answer: Basal ganglia are gray matter structures deep within the white matter
-
Q64. β (Beta) waves of the EEG ---
- Are observed during relaxed wakeful state
- Are faster than alpha waves but slower than theta waves
- Disappear when the person becomes alert D. Are observed during REM sleep
- Mostly on the occipital lobe
- Reduced by routine feedback control
Answer: Are observed during relaxed wakeful state
-
Q65. The prefrontal area is concerned with all the following, except ---
- Adjusting behavior
- Motor guidance within the surrounding environment C. Planning timing of m
- Recall of memories
- Decision making
- Occurs only after chronic exposure
Answer: Adjusting behavior
-
Q66. Mass movements are often stimulated after a meal by distention of the stomach (gastrocolic reflex). Mass movements often lead to ---
- Bowel movements
- Gastric movements
- Esophageal contractions
- Pharyngeal peristalsis
- Limited to a single tissue compartment
Answer: Bowel movements
-
Q67. Postganglionic parasympathetic neurons innervating GI smooth muscle are located in ---
- Myenteric plexus
- Submucosal plexus
- Paravertebral ganglia
- Prevertebral ganglia
- Primarily an incidental laboratory finding
Answer: Myenteric plexus
-
Q68. In healthy humans, the earliest a test meal reaches the cecum is about ---
- 4 hours
- 6 hours
- 9 hours
- 12 hours
- Usually mediated by non-specific mechanisms
Answer: 4 hours
-
Q69. Normally, the main function of the colon is absorption of ---
- Na, Cl, and H2O
- Triacylglycerols
- Secondary bile acids
- Iron
- Mostly unchanged in early disease
Answer: Na, Cl, and H2O
-
Q70. The optimum pH for the activity of pepsin is
- Less than 1
- Between 1.6 and 3.2
- Between 3 and 5
- Between 6 and 7
- Reduced by routine feedback control
Answer: Less than 1