Deck 4: Gastric Secretion and Vomiting

Question 1

Which of the following statements is correct?:

A)The gastric juice contains pepsins,gelatinase,lipase and ?-amylase enzymes.
B)The only essential constituent of the gastric juice is the intrinsic factor.
C)The hunger contractions disappear after bilateral vagotomy or damage of the feeding center in the hypothalamus.
D)HCL is essential for both carbohydrate and fat digestion.

Answer 1

The hunger contractions disappear after bilateral vagotomy or damage of the feeding center in the hypothalamus.

Question 2

Which of the following is the major factor that protects the duodenal mucosa from the damage by gastric acid?:

A)Pancreatic bicarbonate secretions.
B)The endogenous mucosal barrier of the duodenum.
C)Duodenal bicarbonate secretion,
D)Hepatic bicarbonate secretion.

Answer 2

Pancreatic bicarbonate secretions.

Question 3

Which of the following substances is released from the duodenal mucosa in response to acidic gastric juice?:

A)CCK
B)Substance P
C)Secretin
D)GIP

Answer 3

Secretin

Question 4

A 42years old salesman presents with the chief complaint of intermittent midepigastric pain that is relieved by antacids or eating. Gatric analysis reveals that basal and maximal acid output exceed normal values. The gastric hypersecretion can be explained by an increase in the plasma concentration of which of the following?:

A)Somatostatin
B)Histamine
C)Gastrin
D)Secretin

Question 5

Removal of the stomach can lead to all of the following except:

A)Marked digestive disturbances
B)Megaloblastic anaemia (pernicious anaemia)
C)A fall in the plasma volume after a heavy meal (due to the dumping syndrome)
D)Diminished Ca?? absorption and weak development of bones

Question 6

HCl secretion includes all the following processes except:

A)Active transport of H? into gastric lumen
B)H? is exchanged for K? from the extracellular fluid
C)HCO?? diffuse into the extracellular fluid in exchange for Cl?
D)It's associated with production of a postprandial alkaline tide

Question 7

The gastric juice has all the following characteristics except:

A)It contains an alkaline secretion from the surface epithelium
B)It's PH is always less than 3
C)It contains the intrinsic factor which is essential for vit.B?? absorption
D)It's antibacterial action is produced by its mucous content

Question 8

Gastric secretion is inhibited by all the following except:

A)Presence of excess H? in the pyloric antrum
B)Presence of excess protein digestive products in the stomach
C)Certain emotions e.g. fear and depression
D)Certain GIT hormones e.g. secretin,CCK and VIP

Question 9

Concerning HCl secretion, all the following is true except:

A)It's associated with increased PH of the gastric venous blood
B)It's stimulated by gastrin, acetylcholine,histamine and norepinephiren
C)The energy required is derived from ATP breakdown
D)It involves formation of carbonic acid

Question 10

All the following statements are true except:

A)VIP stimulates intestinal secretion and inhibits gastric acid secretions
B)Diamox (a carbonic anhydrase inhibitor) increases both gastric HCL formation and the HCO?? content in the pancreatic juice
C)Both gastrin and glucagons are secreted from the pyloric antrum and duodenum
D)Gastrin is secreted from almost the whole GIT mucosa

Question 11

Which of the following statement is wrong?:

A)The gastric peristalsis includes propulsive,mixing and grinding movements
B)The cephalic phase of gastric secretion involves no release of gastrin.
C)Deficiency of the intrinsic factor causes pernicious anaemia.
D)Large doses of gastrin cause contraction of the pyloric sphincter.

Question 12

The following statements about gastric secretion are correct except:

A)Gastric secretion increases when a hungry person thinks about food
B)Gastric secretion helps vit.B?? absorption
C)Production of HCl depends on activity of carbonic anhydrase
D)Gastric secretion is associated with increased H? concentrarion in venous blood coming from stomach

Question 13

hich of the following statements about gastric secretion is incorrect:

A)Gastric acid secretion can be inhibited by somatostatin
B)The main phase of gastric secretion is the gastric phase
C)Gastric secretion increases in response to the presence of food in mouth after the vagi to stomach have been cut
D)none

Question 14

A 55 years old man with a history of chronic alcohol consumption presents to his local physician with non specific complaints of dyspepsia. Examination and diagnostic testing reveal that he has destruction of the gastric glands. The condition would predispose the patient to which of the following?:

A)Steatorrhea
B)Gastric hypomotility
C)Gastric ulcer
D)Anaemia

Question 15

Which of the following statement about motor function of stomach is untrue?:

A)The frequency of gastric peristaltic contraction is about 3/min
B)Fasting hypoglycemia produces hunger contractions
C)The enterogastric reflex stimulates gastric emptying
D)none

Question 16

Which of the following statement about motor function of stomach is untrue?:

A)Motility of stomach increases when fat enters duodenum
B)MMC prevents duodenogastric reflex
C)Receptive relaxation of stomach is mediated by purinergic vagal fibers
D)non

Question 17

Vomiting:

A)occur only in a denervated stomach
B)Occurs by strong contraction of the stomach wall
C)May be produced by conditioned reflex
D)occur only in an empty stomach

Question 18

Vomiting:

A)Leads to expulsion of gastric contetnts by violent rhythmic contractions of gut smooth ms.
B)Is coordinated by a mid-brain vomiting center
C)Of green fluid suggests that duodenal contents have regurgitated into the stomach
D)May be accompanied by a fall in arterial blood pressure

Question 19

The so-called chemoreceptor trigger zone:

A)Is synonymous with the vomiting center
B)Is located in the cerebral peduncles, ventral to the Aqueduct of Sylvius
C)Is sensitive to the action of morphine
D)May be destroyed experimentally ; the ablation of both chemoreceptor trigger zones abolishes all forms of vomiting

Question 20

As regards the process of vomiting:

A)Its is controlled by a center in the cerebral cortex
B)It always begins with nausea
C)Prolonged vomiting usually produces dehydration associated with acidosis
D)It's associated with relaxation of the body and fundus of the stomach

Question 21

A pyloric obstruction in an infant which results in a prolonged bout of sever vomiting is likely to cause a primary:

A)Metabolic acidosis
B)Metabolic alkalosis
C)Respiratory acidosis
D)Respiratory alkalosis

Question 22

An obstruction of the small bowel leading to sever vomiting with a preponderant loss of duodenal contents is likely to cause a primary:

A)Metabolic acidosis
B)Metabolis alkalosis
C)Respiratory acidosis
D)Respiratory alkalosis

Question 23

A likely reason why a to and fro motion, such as that encountered during airplane flights or in an automobile ride over a bumpy road, tends to cause nausea and vomiting, is because during such motions:

A)Much air is swallowed and the stomach becomes distended
B)The stomach is more likely to develop reverse peristalsis
C)The cerebral cortex can no longer inhibit an intrinsic tendency of the brainstem to cause vomiting
D)Vestibular reflex eventually excite a chemoreceptor trigger zone in the medulla

Question 24

Select a single incorrect answer about vomiting:

A)Vomiting center is in hypothalamus
B)The role of stomach is passive in the process of vomiting
C)Vomiting may occur as a conditioned reflex
D)none

Question 25

Trypsinogen in pancreatic juice is activated by:

A)Alkaline PH
B)Enterokinase
C)Bile salts
D)none