Exam 3A

A researcher compares two peptides: one stimulates gastric acid secretion and motility; the other causes gallbladder contraction and pancreatic enzyme release.

Which two hormones are being studied?

A. Secretin and motilin

B. Gastrin and cholecystokinin

C. Ghrelin and somatostatin

D. Insulin and glucagon

E. VIP and GIP

B. Gastrin and cholecystokinin

Timothy has been having difficulty breathing since he had pneumonia last month. Recently he had severe pain in his chest and back, and his breathing was extremely irregular. The doctor at the emergency room told him that one of the lobes of his lung had collapsed. How could this happen?

A. Timothy suffered atelectasis, or lung collapse, most likely caused by air entering the pleural cavity due to a rupture of the visceral pleura. The rupture could have happened as a result of coughing during his bout with pneumonia

B. Timothy suffered from COPD most likely caused by air entering the pleural cavity due to a rupture of the visceral pleura.

C. Timothy suffered atelectasis, or lung collapse, most likely caused by air exiting the pleural cavity due to a rupture of the visceral pleura. The rupture could have happened as a result of coughing during his bout with pneumonia

D. Timothy suffered atelectasis, or lung collapse, most likely caused by air exiting the pleural cavity due to a rupture of the visceral pleura. The rupture could have happened as a result of sneezing during his bout with COPD

A. Timothy suffered atelectasis, or lung collapse, most likely caused by air entering the pleural cavity due to a rupture of the visceral pleura. The rupture could have happened as a result of coughing during his bout with pneumonia

CADET, face Right!" for CO2, Acid, 2,3-DPG, Exercise and Temperature.Factors that move the oxygen dissociation curve to the right are those physiological states where tissues need more oxygen. Which example is the most accurate

A. For example during exercise, muscles have a higher metabolic rate, and consequently need more oxygen, produce more carbon dioxide and lactic acid, and their temperature rises

B. For example during rest, muscles have a higher metabolic rate, and consequently need more oxygen, produce more carbon dioxide and lactic acid, and their temperature

C. For example during exercise, muscles have a lower metabolic rate, and consequently need more oxygen, produce more carbon dioxide and lactic acid, and their temperature

D. For example during exercise, muscles have a higher metabolic rate, and consequently need less oxygen, produce less carbon dioxide and lactic acid, and their temperature

A. For example during exercise, muscles have a higher metabolic rate, and consequently need more oxygen, produce more carbon dioxide and lactic acid, and their temperature rises

Why is it necessary for the stomach contents to be so acidic? How does the stomach

protect itself from digestion?

A. Pepsin is necessary for the activation and optimal activity of HCl, and it kills many of the bacteria ingested with food. Mucous cells in the lining of the stomach secrete an alkaline mucus that clings to the stomach wall and helps to shield it from the acid

B. HCl is necessary for the activation and optimal activity of pepsin, and it kills many of the bacteria ingested with food. Mucous cells in the lining of the stomach secrete an alkaline mucus that clings to the stomach wall and helps to shield it from the acid

C. Pepsin is necessary for the activation and optimal activity of Glucacon, and it kills many of the bacteria ingested with food. Mucous cells in the lining of the stomach secrete an alkaline mucus that clings to the stomach wall and helps to shield it from the acid

D. Pepsin is necessary for the activation and optimal activity of HCl, and it kills many of the bacteria ingested with food. Mucous cells in the lining of the stomach secrete an acid mucus that clings to the stomach wall and helps to shield it from the Alkaline

B. HCl is necessary for the activation and optimal activity of pepsin, and it kills many of the bacteria ingested with food. Mucous cells in the lining of the stomach secrete an alkaline mucus that clings to the stomach wall and helps to shield it from the acid

A 54-year-old man with a brainstem stroke has irregular, gasping breathing with long pauses (ataxic breathing). Imaging reveals damage to the medulla oblongata.

Which of the following respiratory centers is most likely affected?

A. Apneustic center

B. Pneumotaxic center

C. Dorsal respiratory group (DRG)

D. Cerebellar motor cortex

E. Basal ganglia

C. Dorsal respiratory group (DRG)

A 45-year-old man is involved in a motorcycle accident and sustains a high cervical spinal cord injury at the C3 level. Shortly after, he is found to have paradoxical abdominal movement and requires mechanical ventilation.

Which of the following best explains his respiratory failure?

A. Loss of sympathetic innervation to the lungs

B. Intercostal muscle paralysis

C. Diaphragmatic paralysis due to phrenic nerve disruption

D. Bronchial smooth muscle constriction

E. Obstruction of the upper airway

C. Diaphragmatic paralysis due to phrenic nerve disruption

Deglutition

A) involves the mouth, pharynx and esophagus.

B) occurs in voluntary, pharyngeal and esophageal stages.

C) is controlled directly by the medulla oblongata and the hypothalamus.

D) A and B are correct.

E) A, B and C are correct

D) A and B are correct.

A mountaineer ascends rapidly to 4,500 m. Arrange the following adaptive responses in correct chronological order from first to last:

1. ↑ Erythropoietin → ↑ RBC mass

2. Hyperventilation → respiratory alkalosis

3. ↑ 2,3-DPG → right shift of O₂-Hb curve

4. Renal HCO₃⁻ excretion → pH normalization

5. ↑ Renal EPO synthesis from peritubular fibroblasts

Which sequence is correct?

• A) 1 → 2 → 3 → 4 → 5

• B) 2 → 4 → 3 → 5 → 1

• C) 3 → 2 → 1 → 4 → 5

• D) 2 → 3 → 5 → 4 → 1

• E) 4 → 2 → 3 → 1 → 5

• B) 2 → 4 → 3 → 5 → 1

An individual suffering from hyposecretion by gastric chief cells would have

A) inadequate amounts of intrinsic factor and HCl.

B) excessive amounts of intrinsic factor and HCl.

C) inadequate amounts of pepsinogen and gastric lipase.

D) excessive amounts of pepsinogen and gastric lipase.

E) inadequate amounts of mucus.

C) inadequate amounts of pepsinogen and gastric lipase.

Which of the following is NOT correct?

A) Food may remain in the gastric fundus for an hour without mixing with gastric juice.

B) 2-4 peristaltic mixing waves pass through the stomach wall each minute.

C) Salivary amylase is inactivated by the low pH of gastric juice.

D) Lingual lipase is inactivated by the low pH of gastric juice.

E) The pyloric sphincter allows small volumes of chyme to enter the duodenum.

D) Lingual lipase is inactivated by the low pH of gastric juice.

A patient with end-stage Liver Cirrhosis presents with severe edema (swelling) in their

legs and a confused, altered mental state (Encephalopathy). Based on liver metabolism,

which two failures are occurring?

A) Failure of Gluconeogenesis (low energy) and failure of Ketogenesis (brain starvation).

B) Failure of Albumin synthesis (low osmotic pressure causes edema) and failure of the Urea Cycle (ammonia buildup causes brain toxicity).

C) Failure of Bile production (fatty stools) and failure of Glycogenolysis (fainting).

D) Failure of Phase II Detoxification and over-production of VLDLs.

B) Failure of Albumin synthesis (low osmotic pressure causes edema) and failure of the Urea Cycle (ammonia buildup causes brain toxicity).

Chronic cigarette smoking causes a measurable increase in goblet cell number and mucus production in bronchial epithelium. Which of the following is the most accurate histological description of this change and its consequence?

A) Goblet cell hyperplasia → ↑mucus → impaired mucociliary clearance → chronic productive cough

B) Goblet cell atrophy → ↓mucus → airway desiccation → dry nonproductive cough

C) Conversion of goblet cells to type II pneumocytes → surfactant overproduction

D) Goblet cell metaplasia replacing club cells → ↑bronchoconstriction

E) Squamous metaplasia of goblet cells → ↑diffusion capacity

A) Goblet cell hyperplasia → ↑mucus → impaired mucociliary clearance → chronic productive cough

When measuring the diffusion distance for O₂ from alveolar air to hemoglobin inside an RBC, which sequence of layers is crossed in order?

A) Surfactant → type II pneumocyte → basement membrane → endothelium → plasma → RBC membrane

B) Surfactant layer → type I pneumocyte cytoplasm → fused basement membranes → capillary endothelium cytoplasm → plasma → RBC membrane

C) Type I pneumocyte → interstitial space → type II pneumocyte → endothelium → plasma

D) Alveolar macrophage → type I pneumocyte → basement membrane → RBC

E) Mucus layer → pseudostratified epithelium → cartilage → smooth muscle → endothelium

B) Surfactant layer → type I pneumocyte cytoplasm → fused basement membranes → capillary endothelium cytoplasm → plasma → RBC membrane

A slide shows an airway without cartilage, without goblet cells, lined by simple columnar epithelium with occasional dome-shaped non-ciliated cells, and surrounded by a prominent smooth muscle layer. What structure is this most likely?

A) Primary bronchus

B) Secondary (lobar) bronchus

C) Terminal bronchiole

D) Respiratory bronchiole

E) Alveolar duct

C) Terminal bronchiole

A healthy subject eats a high-fat, high-protein meal. Rank the following GI hormones by their predominant timing and function during the 3 hours post-meal: Gastrin (G), Secretin (S), CCK (C), GIP (I), Motilin (M).

A) M → G → C → S → I (in order of meal response)

B) G → C and S simultaneously → I → M (after stomach empties)

C) S → G → C → M → I

D) C → G → S → M → I

E) G → S → C → I → M (returns during late fasting)

E) G → S → C → I → M (returns during late fasting)

A patient with a spinal cord injury at T10 asks why they can no longer voluntarily control defecation but still experience reflex defecation. Which neural mechanism explains this dissociation?

A) The sympathetic chain at T10 controls the external anal sphincter; injury removes voluntary control while parasympathetics remain intact

B) The intrinsic defecation reflex (via myenteric plexus) remains intact below the lesion; voluntary control requires an intact corticospinal pathway to the external anal sphincter (somatic, pudendal nerve, S2-S4)

C) The internal anal sphincter (IAS) is voluntarily controlled via the pudendal nerve; injury removes this control

D) The sacral defecation center is destroyed at T10, eliminating all reflex activity

E) The enteric nervous system is completely dependent on spinal cord input for peristalsis

B) The intrinsic defecation reflex (via myenteric plexus) remains intact below the lesion; voluntary control requires an intact corticospinal pathway to the external anal sphincter (somatic, pudendal nerve, S2-S4)

A 52-year-old man with chronic alcoholic pancreatitis develops steatorrhea. His fecal fat test shows 28 g/day (normal < 7 g/day). He is started on pancreatic enzyme replacement therapy (PERT). Which enzyme component is MOST critical for fat absorption, and at what intraluminal pH does it function optimally?

A) Pancreatic amylase; optimal pH 6.5–7.0

B) Pancreatic lipase; optimal pH 7.0–8.0; requires colipase and bile salts

C) Phospholipase A2; optimal pH 5.0; functions independently

D) Cholesterol esterase; optimal pH 4.0; activated by trypsin

E) Lingual lipase; optimal pH 3.5–6.0; primary fat digestion enzyme

B) Pancreatic lipase; optimal pH 7.0–8.0; requires colipase and bile salts

A patient undergoes surgical section of the vagus nerves (vagotomy= CUTTING VAGUS NERVE) AND intraduodenal infusion of HCl is blocked experimentally. Which pancreatic secretory component would be MOST severely reduced?

A) Enzyme secretion stimulated by CCK from I cells

B) Bicarbonate-rich fluid secretion stimulated by secretin from S cells

C) Basal pancreatic enzyme secretion mediated by vagal ACh

D) Insulin secretion from beta cells in response to glucose

E) Glucagon secretion from alpha cells during fasting

C) Basal pancreatic enzyme secretion mediated by vagal ACh

A researcher perfuses an isolated submandibular gland with atropine and then applies electrical stimulation to the parasympathetic fibers. Which of the following best describes the expected secretory output?

A) Copious watery saliva due to unopposed sympathetic stimulation

B) Thick, mucus-rich saliva because muscarinic blockade shifts dominance to sympathetic adrenergic pathways

C) No saliva at all since both arms of the autonomic system are blocked

D) Normal saliva because atropine has no effect on salivary glands

E) Increased amylase secretion only, with no fluid component

B) Thick, mucus-rich saliva because muscarinic blockade shifts dominance to sympathetic adrenergic pathways

A patient undergoes surgical section of the vagus nerves (vagotomy) AND intraduodenal infusion of HCl is blocked experimentally. Which pancreatic secretory component would be MOST severely reduced?

A) Enzyme secretion stimulated by CCK from I cells

B) Bicarbonate-rich fluid secretion stimulated by secretin from S cells

C) Basal pancreatic enzyme secretion mediated by vagal ACh

D) Insulin secretion from beta cells in response to glucose

E) Glucagon secretion from alpha cells during fasting

C) Basal pancreatic enzyme secretion mediated by vagal ACh

During normal fetal development, the synthesis of dipalmitoylphosphatidylcholine (DPPC, or lecithin) surges around week 35, altering the amniotic fluid Lecithin/Sphingomyelin (L/S) ratio. A pregnant patient at 36 weeks gestation with chronically poorly controlled gestational diabetes undergoes an amniocentesis, which reveals an L/S ratio of 2.3 (reference for maturity is typically $\ge$ 2.0). However, upon delivery, the neonate immediately exhibits grunting, severe retractions, and cyanosis consistent with Neonatal Respiratory Distress Syndrome (NRDS). Which of the following best explains why the standard predictive value of the L/S ratio failed in this specific patient?

A) Chronic fetal hyperglycemia induced premature apoptosis of Type I pneumocytes, rendering the mature surfactant useless.

B) Fetal hyperinsulinemia inhibited the maturation of Type II pneumocytes and the synthesis of phosphatidylglycerol (PG), despite sufficient lecithin production.

C) High maternal glucose crossed the placenta, directly denaturing the hydrophobic tails of the amniotic sphingomyelin, artificially inflating the L/S ratio.

D) Fetal cortisol levels were suppressed by maternal hyperglycemia, preventing the conversion of sphingomyelin into active surfactant proteins.

B) Fetal hyperinsulinemia inhibited the maturation of Type II pneumocytes and the synthesis of phosphatidylglycerol (PG), despite sufficient lecithin production.

An experimental drug selectively inhibits the Myenteric (Auerbach’s) Plexus while leaving the Submucosal (Meissner’s) Plexus intact. Which physiological deficit would be most prominent in the patient?

A) A complete inability to secrete bicarbonate in response to acidic chyme in the duodenum.

B) A failure to regulate the blood flow to the villi, leading to localized ischemia during digestion.

C) A loss of coordinated peristaltic contractions, despite the ability to still regulate glandular secretions.

D) The inability of the brush border enzymes to perform final hydrolysis of disaccharides.

C) A loss of coordinated peristaltic contractions, despite the ability to still regulate glandular secretions.

A patient is taking a high-dose Proton Pump Inhibitor (PPI) which significantly raises their gastric $pH$ from 2.0 to 5.5. How will this most likely affect the Pancreatic response to a meal?

A) Secretin release will decrease, leading to a lower volume of bicarbonate-rich pancreatic juice.

B) CCK release will increase to compensate for the lack of acid-driven digestion.

C) Gastrin levels will drop because the stomach is no longer acidic.

D) Enterokinase will be denatured, preventing the activation of Trypsinogen.

A) Secretin release will decrease, leading to a lower volume of bicarbonate-rich pancreatic juice.

A patient has a condition where their Vagus nerve is severely damaged (Neuropathy). After eating a meal high in fried fats, they experience significant bloating and undigested fat in their stool. Given that CCK levels in their blood are normal, why is their gallbladder failing to contract efficiently?

A) CCK cannot act on the gallbladder without the presence of Gastrin.

B) CCK’s action on gallbladder contraction is partially mediated by a "Vago-vagal" reflex that requires intact neural pathways.

C) The gallbladder only responds to neural stimulation, not hormonal stimulation.

D) Without the Vagus nerve, the I-cells cannot sense fatty acids in the lumen.

B) CCK’s action on gallbladder contraction is partially mediated by a "Vago-vagal" reflex that requires intact neural pathways.

If a patient is taking a Trypsin Inhibitor drug, what would be the expected effect on their endogenous CCK levels?

A) CCK levels will decrease because Trypsin is required to activate I-cells.

B) CCK levels will remain chronically elevated because the "off switch" (Trypsin-mediated degradation of releasing peptides) is blocked.

C) CCK levels will fluctuate wildly because the pancreas will stop producing enzymes.

D) CCK will be converted into Secretin to compensate for the lack of Trypsin.

B) CCK levels will remain chronically elevated because the "off switch" (Trypsin-mediated degradation of releasing peptides) is blocked.

A patient undergoes a selective vagotomy (severing of the Vagus nerve) to treat a chronic peptic ulcer. Following the procedure, which of the following best describes the resulting shift in gastric physiology?

A) Gastrin secretion becomes zero because the G-cells lose all excitatory input.

B) The Cephalic phase of digestion is abolished, but the Gastric phase remains functional via local distension and Gastrin-Releasing Peptide (GRP).

C) Somatostatin levels will plummet because the Vagus nerve is the primary stimulator of D- cells.

D) Post-prandial $pH$ will drop faster than normal due to the loss of inhibitory parasympathetic tone on Parietal cells.

B) The Cephalic phase of digestion is abolished, but the Gastric phase remains functional via local distension and Gastrin-Releasing Peptide (GRP).

Tasha’s tidal volume is half her expiratory reserve volume. Her inspiratory reserve volume is twice as big as her expiratory reserve volume. Her vital capacity is 5250mL. what is her IRV?

A. IRV = 2000 mL

B. IRV = 3000 Ml

C. IRV = 4000 mL

D. IRV = 4500 mL

E. IRV = 6000 Ml

B. IRV = 3000 Ml

Unlike inspiration, expiration is a passive act because no muscular contractions are involved. Expiration, however, depends on two factors. Which of the choices below lists those two factors?

A) the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

B) the expansion of respiratory muscles that were contracted during inspiration and the lack of surface tension on the alveolar wall

C) the negative feedback of expansion fibers used during inspiration and the outward pull of surface tension due to surfactant

D) combined amount of CO2 in the blood and air in the alveoli

A) the recoil of elastic fibers that were stretched during inspiration and the inward pull of surface tension due to the film of alveolar fluid

The reaction of carbon dioxide with water is a relatively slow process yet this reaction occurs within the red cells in a fraction of a second. What is responsible for speeding up this reaction?

A. cytochrome oxidase

B. adenosine triphosphate

C. phosphorylase

D. carbonic anhydrase

D. carbonic anhydrase

A patient has a tidal volume of 500 mL and a respiratory rate of 16 breaths/min. What is the patient's minute ventilation?

A. 2.0 L/min

B. 4.0 L/min

C. 6.0 L/min

D. 8.0 L/min

E. 10.0 L/min

D. 8.0 L/min

The Great Zoltan is a magician. He has locked himself in a small, air-tight container, and his assistant has lowered him under water. After five minutes, the fractional content of carbon dioxide in the air Zoltan is breathing has increased to 2%. If the total pressure of the air Zoltan is CO2 breathing is the same as regular air at sea level ( 760 mm Hg), then what is the P of the air that Zoltan is breathing?

A. about 0.15 mm Hg

B. about 2 mm Hg

C. about 15 mm Hg

D. about 159 mm Hg

E. None of the answers above is close to the correct answer.

C. about 15 mm Hg

A surgeon performing a right lower lobectomy must identify the segmental bronchi. Which of the following correctly describes the branching pattern of the tracheobronchial tree at the level of the secondary bronchi?

A) The right primary bronchus branches into 2 lobar bronchi; the left into 3

B) Both primary bronchi branch symmetrically into 3 lobar bronchi each

C) The right primary bronchus branches into 3 lobar bronchi; the left into 2

D) Lobar bronchi are lined by simple squamous epithelium for gas exchange

E) The carina is located at the level of the T4 vertebra and divides into equal bro

C) The right primary bronchus branches into 3 lobar bronchi; the left into 2

About 1/4000 babies are born with esophageal atresia, a condition in which the esophagus does not connect to the stomach. Many of these infants also have a fistula, or opening, that connects the esophagus to the trachea. How will esophageal atresia with tracheosesophageal fistula affect an infant?

A) The infant will not be able to pass milk to its stomach.

B) The infant will not be able to absorb nutrients from milk.

C) The infant may develop pneumonia from milk entering the lungs.

D) A and B are correct.

E) A, B and C are correct.

E) A, B and C are correct.

Most foreign substances in inspired air fail to reach the lungs because of the

A. ciliated mucous lining in the nasopharynx and trachea.

B. porous structure of turbinate bones.

C. cartilaginous sections of nasal septum.

D. poor blood supply to nasal mucosa.

E. more vertical nature of the right primary bronchus.

A. ciliated mucous lining in the nasopharynx and trachea.

68-year-old man with a history of COPD presents to the emergency department with increasing shortness of breath, confusion, and drowsiness over the past 24 hours. His respiratory rate is 10 breaths/min. ABG shows:

• pH: 7.28

• PaCO₂: 62 mmHg

• PaO₂: 58 mmHg

• HCO₃⁻: 30 mEq/L

He is on home oxygen at 4 L/min via nasal cannula.

Which of the following is the most likely physiological explanation for his respiratory depression?

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

B. Excess oxygen decreased pulmonary vascular resistance, improving ventilation-perfusion (V/Q) matching

C. Peripheral chemoreceptors suppressed respiratory drive due to low pH

D. Respiratory alkalosis suppressed medullary respiratory centers

E. His alveolar dead space increased, enhancing CO₂ clearance

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

Bjorn is a 37yo Swedish male who stands 6’6” and weighs in at 307lbs. He is a cigarette smoker, a movie fan, an alcoholic, and enjoys quiet sunset walks on the beach. As he grows older,

What will happen to his vital capacity? What will happen to his residual volume?

A. Decrease - Increase

B. Increase -Decrease

C. Decrease –decrease

D. Increase- Increase

E. No change for both

A. Decrease - Increase

Given the following, calculate the tidal volume.

• Vital capacity = 5000 mL

• Inspiratory reserve volume = 3 L

• Expiratory reserve volume = 1500 mL

What is the tidal volume ?

A. 300 ml

B. 400 ml

C. 450 ml

D. 500 ml

E. 600ml

F. 6000ml

D. 500 ml

Which statement BEST describes ventilation-perfusion differences in the upright lung?

A. Apex has low V/Q due to high perfusion

B. Base has high V/Q due to high ventilation

C. Apex has high V/Q due to relatively low perfusion

D. Base has equal ventilation and perfusion

E. V/Q is uniform throughout lung

C. Apex has high V/Q due to relatively low perfusion

A 45-year-old man undergoes upper endoscopy for chronic epigastric pain. Biopsy of the gastric fundus shows oxyntic glands with abundant acid-secreting cells that have prominent intracellular canaliculi and tubulovesicular structures containing H+/K+-ATPase. A separate biopsy from the pyloric antrum reveals glands rich in mucus-secreting cells and endocrine cells that produce gastrin. Which of the following best explains the primary physiologic difference between these two regions?

A) Fundic glands primarily secrete pepsinogen; antral glands secrete HCl

B) Fundic parietal cells actively transport H+ against a gradient via ATP-dependent pumps; antral G cells respond to luminal pH via somatostatin inhibition

C) Both regions have identical gland architecture, but fundic glands lack muscularis mucosae

D) Antral glands contain chief cells that produce intrinsic factor for B12 absorption

E) Fundic glands are simple tubular; antral glands are branched and lack enteroendocrine cells

B) Fundic parietal cells actively transport H+ against a gradient via ATP-dependent pumps; antral G cells respond to luminal pH via somatostatin inhibition

During a research study, electron microscopy of duodenal enterocytes reveals apical microvilli with a dense glycocalyx and underlying terminal web of actin filaments. Adjacent goblet cells show large apical mucin granules that discharge via merocrine secretion. In contrast, ileal enterocytes overlie lymphoid aggregates with specialized flattened epithelial cells that sample luminal antigens via endocytosis and transcytosis. Which structure is most responsible for the ileum's unique immunologic surveillance function described here?

A) Brunner's glands in the submucosa

B) Crypts of Lieberkühn containing Paneth cells

C) M cells overlying Peyer's patches

D) Enterochromaffin cells releasing serotonin

E) Auerbach's plexus coordinating peristalsis

C) M cells overlying Peyer's patches

Which of the following statements best describes the primary function of the diaphragm in respiration and its anatomical relationship with the abdominal cavity?

A) The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity and decreasing the pressure, while simultaneously decreasing the pressure in the abdominal cavity, allowing the organs to expand.

B) The diaphragm relaxes during inhalation, causing the thoracic cavity to decrease in volume and the abdominal cavity pressure to increase, forcing air into the lungs.

C) The diaphragm contracts during exhalation, pushing air out of the lungs by increasing the intra-abdominal pressure, which also causes compression of the stomach and intestines.

D) The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity and decreasing the pressure in the lungs, which causes air to enter the lungs.

E) The diaphragm plays a minor role in respiration, with the primary function of assisting digestion by compressing the intestines during exhalation.

D) The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity and decreasing the pressure in the lungs, which causes air to enter the lungs.

The amount of air that can be forcibly inhaled after a normal inhalation is known as:

A) Tidal volume

B) Vital capacity

C) Inspiratory reserve volume

D) Expiratory reserve volume

E) Functional residual capacity

C) Inspiratory reserve volume

The central chemoreceptors, which help regulate breathing rate, primarily respond to

changes in which of the following?

A) Blood oxygen levels

B) Blood glucose levels

C) Blood carbon dioxide levels

D) Blood pH levels

E) Blood pressure

C) Blood carbon dioxide levels

The mucosa of the alimentary canal

A) is composed of 3 layers: epithelium, the lamina propria and the muscularis mucosae.

B) lines the lumen of the alimentary canal.

C) includes an inner sheet of circular muscle fibers and an outer layer of longitudinal fibers.

D) A and B are correct.

E) A, B and C are correct.

D) A and B are correct.

The enteric nervous system

A) controls GI tract motility via the myenteric plexus.

B) controls GI tract secretions via the submucosal plexus.

C) contains interneurons that coordinate secretions and motility.

D) A and B are correct.

E) A, B and C are correct.

E) A, B and C are correct.

During abdominal surgery, immobilization of the patient’s intestines is often desirable. Which of the following types of medications would be most effective at immobilizing the intestines?

A) a cholinergic medication

B) an anticholinergic medication

C) an antiadrenergic medication

D) Both A and C are correct.

E) Both B and C are correct.

B) an anticholinergic medication

The tongue

A) forms the roof of the mouth and is covered by a serous membrane.

B) secretes lingual amylase.

C) contains intrinsic muscles used in speaking and swallowing.

D) contains taste buds in papillae on its ventral and medial surfaces.

E) All of these are correct.

C) contains intrinsic muscles used in speaking and swallowing.

A lab group is sent to the cafeteria to do an experiment. The instructions direct each student to obtain a regular saltine cracker and to chew it 25 times before swallowing. The students are to observe and record the initial and final tastes of the cracker. Most students record that the cracker initially tastes salty, but then tastes sweet. Which of the following correctly explains the students’ observations?

A) The salt on the crackers dissolved rapidly in saliva and was quickly detected by taste buds.

B) Salivary amylase digested the cracker’s starch into sugars that could be then be tasted.

C) Lingual lipase digested the cracker’s fat into sugars that could then be tasted.

D) A and B are correct.

E) A and C are correct.

D) A and B are correct.

A gastroenterology fellow is asked to predict the consequence of surgical resection of different intestinal segments. Match each segment to its UNIQUE or PRIMARY absorptive function: Which answer correctly pairs segment → unique function?

• A) Duodenum → vitamin B12; Jejunum → bile salts; Ileum → iron and folate

• B) Duodenum → iron, folate, Ca²⁺, fat-soluble vitamins; Jejunum → majority of nutrients (carbs, protein, fat, water-soluble vitamins); Ileum → bile salts and vitamin B12

• C) Jejunum → bile salts; Ileum → glucose; Colon → fat absorption

• D) Duodenum → B12; Jejunum → bile salts; Ileum → iron and water

• E) Ileum → all nutrients; Duodenum → water and electrolytes only

• B) Duodenum → iron, folate, Ca²⁺, fat-soluble vitamins; Jejunum → majority of nutrients (carbs, protein, fat, water-soluble vitamins); Ileum → bile salts and vitamin B12

An elderly women, with several cardiovascular problems, cames to see her doctor for blood in the feces, without any symptoms. Few hours later the patient is in hypovolemic shock, with a hyperdistension of her abdomen. An xray shows level in the middle quadran. After , preparation and stabilization an emergency surgery is started. A necrosis of the ileum and ascending colon is the finding caused by an emboli in one of her main vessels. During surgery the patient died, from a massive Myocardial infarct. The cause of the emboli is

the obstruction of which vasculature

A. The Aorta

B. The Superior mesenteric artery

C. The inferior mesenteric artery

D. the Coeliac trunk

E. Both of the mesenteric Artery

B. The Superior mesenteric artery

A 68-year-old man with a history of COPD presents to the emergency department with

increasing shortness of breath, confusion, and drowsiness over the past 24 hours. His

respiratory rate is 10 breaths/min. ABG shows:

• pH: 7.28

• PaCO₂: 62 mmHg

• PaO₂: 58 mmHg

• HCO₃⁻: 30 mEq/L

He is on home oxygen at 4 L/min via nasal cannula.

Which of the following is the most likely physiological explanation for his respiratory depression?

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

B. Excess oxygen decreased pulmonary vascular resistance, improving ventilation-perfusion (V/Q) matching

C. Peripheral chemoreceptors suppressed respiratory drive due to low pH

D. Respiratory alkalosis suppressed medullary respiratory centers

E. His alveolar dead space increased, enhancing CO₂ clearance

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

Which of the following best describes the epithelial change as the respiratory tract transitions from bronchi to terminal bronchioles?

A. Simple squamous → stratified squamous non-keratinized

B. Pseudostratified columnar → simple cuboidal

C. Simple cuboidal → pseudostratified columnar

D. Stratified cuboidal → stratified columnar

E. Simple squamous → simple cuboidal

B. Pseudostratified columnar → simple cuboidal

Which of the following best describes the function of Clara (Club) cells, found in the terminal bronchioles of the lung?

A. Mucus secretion and mucociliary clearance

B. Phagocytosis of alveolar debris and pathogens

C. Surfactant protein production and detoxification of inhaled substances

D. Gas exchange via thin squamous epithelium

E. Immune presentation of antigens to alveolar macrophages

C. Surfactant protein production and detoxification of inhaled substances

What is and where is the pectinate line

A. is a line which divides the upper 2/3rds and lower 1/3rd of the gastric canal

B. is a line which divides the upper 2/3rds and lower 1/3rd of the pulmonary diaphragmatic lining

C. is a line which divides the upper 2/3rds and lower 1/3rd of the anal canal

D. is a line which divides the anal canal

C. is a line which divides the upper 2/3rds and lower 1/3rd of the anal canal

What structures are used by both the respiratory and digestive systems?

A. Oropharynx and laryngopharynx

B. Laryngopharynx and larynx

C. Nasal cavity and nasopharynx

D. Paranasal sinuses

E. Laryngopharynx and esophagus

A. Oropharynx and laryngopharynx

A 68-year-old man with a history of COPD presents to the emergency department with increasing shortness of breath, confusion, and drowsiness over the past 24 hours. His respiratory rate is 10 breaths/min. ABG shows:

• pH: 7.28

• PaCO₂: 62 mmHg

• PaO₂: 58 mmHg

• HCO₃⁻: 30 mEq/L

He is on home oxygen at 4 L/min via nasal cannula.

Which of the following is the most likely physiological explanation for his respiratory depression?

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

B. Excess oxygen decreased pulmonary vascular resistance, improving ventilation-perfusion (V/Q) matching

C. Peripheral chemoreceptors suppressed respiratory drive due to low pH

D. Respiratory alkalosis suppressed medullary respiratory centers

E. His alveolar dead space increased, enhancing CO₂ clearance

A. Central chemoreceptors are less sensitive due to chronic CO₂ retention

Which of the following best describes the epithelial change as the respiratory tract transitions from bronchi to terminal bronchioles?

A. Simple squamous → stratified squamous non-keratinized

B. Pseudostratified columnar → simple cuboidal

C. Simple cuboidal → pseudostratified columnar

D. Stratified cuboidal → stratified columnar

E. Simple squamous → simple cuboidal

B. Pseudostratified columnar → simple cuboidal

What is and where is the pectinate line

E. is a line which divides the upper 2/3rds and lower 1/3rd of the gastric canal

F. is a line which divides the upper 2/3rds and lower 1/3rd of the pulmonary

diaphragmatic lining

G. is a line which divides the upper 2/3rds and lower 1/3rd of the anal canal

H. is a line which divides the anal canal

G. is a line which divides the upper 2/3rds and lower 1/3rd of the anal canal

Place the following in the order in which chyme and, ultimately, feces pass through them.

1. descending colon

2. ascending colon

3. sigmoid colon

4. ileocecal valve

5. Rectum

6. transverse colon

7. cecum

8. anus

A) 4, 7, 2, 6, 1, 3, 5, 8

B) 4, 7, 1, 6, 2, 3, 5, 8

C) 4, 7, 2, 1, 6, 3, 5, 8

D) 4, 7, 6, 2, 1, 3, 5, 8

E) 4, 7, 2, 6, 1, 5, 3, 8

A) 4, 7, 2, 6, 1, 3, 5, 8

Tasha’s tidal volume is half her expiratory reserve volume. Her inspiratory reserve

volume is twice as big as her expiratory reserve volume. Her vital capacity is 5250mL.

Calculate her TV, IRV, ERV.

A. TV = 750 ml ERV = 1500 ml IRV = 3000 ml

B. TV = 770 ml ERV = 1500 ml IRV = 3000 ml

C. TV = 900 ml ERV = 2500 ml IRV = 3000 ml

D. TV = 750 ml ERV = 2500 ml IRV = 3000 ml

E. TV = 750 ml ERV = 1500 ml IRV = 6000 ml

A. TV = 750 ml ERV = 1500 ml IRV = 3000 ml