Nokea
Water transport can occur from the lumen of the intestine to the blood stream, or from the blood stream to the intestinal lumen. Which single statement about this phenomenon, below, is actually correct?
- A. A 'flip-flop' mechanism efficiently transports water directly across the enterocyte membrane
- B. Water flows into the gut from the mucosa, during digestion of starch and protein, in order to reduce luminal osmolality
- C. Water is mostly absorbed by movement between the cells lining the gut (enterocytes) via tight junctions
- D. Dietary intake of water is always greater than water movement in the small intestine
Correct Answer: C
Rationale: The correct answer is C because water is indeed mostly absorbed by movement between the cells lining the gut (enterocytes) via tight junctions. This is known as paracellular transport. Water moves through the spaces between the cells due to osmotic gradients and is then taken up by blood vessels. A: The 'flip-flop' mechanism is not a recognized mechanism for water transport in the intestine. B: Water does not flow into the gut from the mucosa during digestion, rather it moves from the gut lumen into the blood. D: Dietary intake of water can vary and may not always be greater than water movement in the small intestine.
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What is the role of the colon in digestion?
- A. digestion of carbohydrates
- B. absorption of water and electrolytes
- C. production of bile
- D. secretion of enzymes
Correct Answer: B
Rationale: The colon's main role in digestion is the absorption of water and electrolytes from undigested food, forming feces. This process helps maintain body fluid balance. The other choices are incorrect because: A) Carbohydrates are primarily digested in the small intestine. C) Bile is produced in the liver and stored in the gallbladder, aiding in fat digestion in the small intestine. D) Enzymes are secreted in the stomach and small intestine to aid in digestion, not in the colon.
The major secretory product of the colon is
- A. bicarbonate ions.
- B. mucus.
- C. digestive enzymes.
- D. hydrochloric acid.
Correct Answer: B
Rationale: The correct answer is B: mucus. The colon secretes mucus to protect the lining from digestive enzymes and acids, aid in the passage of stool, and maintain proper intestinal function. Bicarbonate ions (A) are secreted in the pancreas to neutralize stomach acid. Digestive enzymes (C) are primarily secreted in the small intestine to break down nutrients. Hydrochloric acid (D) is secreted by the stomach to aid in digestion but not by the colon.
Priority Decision: During the treatment of the patient with bleeding esophageal varices, what is the most important thing the nurse should do?
- A. Prepare the patient for immediate portal shunting surgery.
- B. Perform guaiac testing on all stools to detect occult blood.
- C. Maintain the patient's airway and prevent aspiration of blood.
- D. Monitor for the cardiac effects of IV vasopressin and nitroglycerin.
Correct Answer: C
Rationale: Rationale: The correct answer is C because maintaining the patient's airway and preventing aspiration of blood is the top priority in a patient with bleeding esophageal varices. This is crucial to prevent respiratory compromise and potential life-threatening complications. Immediate portal shunting surgery (A) is not the priority as stabilizing the patient comes first. Guaiac testing (B) is not the priority as it does not address the immediate risk of airway obstruction. Monitoring cardiac effects (D) is important but not as critical as ensuring the patient's airway is secure.
A patient comes to the hospital complaining of vomiting and diarrhoea. The doctor suggested that the patient take glucose and electrolyte solution orally. Which one of following membrane proteins is likely to be involved in rehydrating the patient?
- A. Cystic fibrosis transmembrane regulator (CFTR)
- B. Sodium glucose transporter protein! (SGLT1)
- C. Insulin receptor protein (IRP)
- D. Sucrase-isomaltase protein (SIP)
Correct Answer: B
Rationale: The correct answer is B: Sodium glucose transporter protein 1 (SGLT1). SGLT1 is responsible for the active transport of glucose and sodium across the intestinal membrane. When a patient is experiencing vomiting and diarrhea, they are losing fluids and electrolytes. By taking a glucose and electrolyte solution orally, the SGLT1 protein helps in the reabsorption of glucose and sodium to facilitate rehydration.
Incorrect choices:
A: Cystic fibrosis transmembrane regulator (CFTR) is associated with cystic fibrosis and does not play a direct role in rehydration.
C: Insulin receptor protein (IRP) is involved in glucose uptake regulation in response to insulin, not rehydration.
D: Sucrase-isomaltase protein (SIP) is involved in the breakdown of sugars in the small intestine, not rehydration.
Which one of the following is the correct pathway of bile from the hepatocytes to the gallbladder?
- A. bile canaliculus → hepatic duct → common hepatic duct → common bile duct → gallbladder.
- B. bile canaliculus → hepatic duct → cystic duct → common hepatic duct → gallbladder.
- C. hepatic sinusoid → central vein → hepatic vein → gall bladder.
- D. bile canaliculus → hepatic duct → common hepatic duct → cystic duct → gallbladder.
Correct Answer: D
Rationale: The correct answer is D: bile canaliculus → hepatic duct → common hepatic duct → cystic duct → gallbladder. This pathway reflects the anatomical sequence of bile flow from the smallest bile ducts within the liver (bile canaliculi) to the gallbladder. Bile canaliculi collect bile from hepatocytes, which then flows through larger ducts (hepatic duct, common hepatic duct) before reaching the cystic duct, which connects to the gallbladder for bile storage.
Choices A, B, and C are incorrect because they do not follow the correct anatomical pathway of bile flow. For example, in choice A, the common hepatic duct should connect directly to the cystic duct, not the common bile duct. In choice B, the cystic duct should not connect to the common hepatic duct. In choice C, bile does not flow through the central vein or hepatic vein