Nokea
Which statement about the oral phase of digestion is INCORRECT?
- A. About 2% of the energy content of food is expended during the action of chewing and swallowing it.
- B. Swallowing involves contraction and relaxation of at least 14 groups of muscles in about 10 seconds in healthy subjects
- C. The biofilm covering tooth enamel contains several salivary and bacterial enzymes
- D. Salivary amylase digests the dextran film on tooth enamel formed from dietary sucrose
Correct Answer: D
Rationale: Correct Answer: D
Rationale: Salivary amylase primarily digests carbohydrates in the oral cavity, breaking down starch into simpler sugars like maltose. It does not directly target the dextran film on tooth enamel formed from dietary sucrose. This film is typically broken down by dental plaque bacteria, not salivary amylase. Therefore, option D is incorrect.
Summary of Incorrect Choices:
A: This statement is correct. Chewing and swallowing do require energy expenditure.
B: This statement is correct. Swallowing involves the coordinated action of multiple muscle groups.
C: This statement is correct. The biofilm on tooth enamel contains enzymes from both saliva and bacteria, contributing to oral digestion.
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Where is the majority of absorption of nutrients in the digestive tract?
- A. stomach
- B. small intestine
- C. large intestine
- D. mouth
Correct Answer: B
Rationale: The majority of absorption of nutrients occurs in the small intestine. This is because the small intestine has a large surface area due to its villi and microvilli, which increase the absorption capacity. Additionally, the small intestine contains specialized cells that facilitate the absorption of nutrients into the bloodstream. In contrast, the stomach's main function is to break down food, the large intestine primarily absorbs water and electrolytes, and the mouth is responsible for initial digestion through chewing and saliva production. Therefore, choice B is correct as it aligns with the anatomical and physiological functions of the digestive system.
A patient diagnosed with chronic hepatitis B asks about drug therapy to treat the disease. What is the most appropriate response by the nurse?
- A. Only chronic hepatitis C is treatable and primarily with antiviral agents and interferon.'
- B. There are no specific drug therapies that are effective for treating acute viral hepatitis.'
- C. Interferon combined with lamivudine (Epivir) will decrease viral load and prevent complications.'
- D. There are no drugs used for the treatment of viral hepatitis because of the risk of additional liver damage.'
Correct Answer: C
Rationale: For chronic hepatitis B, antiviral therapy such as interferon and lamivudine (Epivir) is used to reduce the viral load and prevent complications like cirrhosis.
The tunica muscularis in the superior esophagus is made up of ______ muscle.
- A. skeletal
- B. cardiac
- C. smooth
- D. smooth and skeletal
Correct Answer: A
Rationale: The correct answer is A: skeletal muscle. The superior esophagus contains skeletal muscle in its tunica muscularis, allowing for voluntary control over swallowing. Cardiac muscle is found in the heart, not in the esophagus. Smooth muscle is present in the lower esophagus for involuntary movements. Choice D is incorrect as the superior esophagus does not contain a mix of smooth and skeletal muscle.
Which of the following statements is TRUE? The protein FOXO1:
- A. activates (increases the expression of) genes related to greater longevity
- B. is activated by caloric restriction
- C. is deactivated by increased insulin signalling
- D. all of the above are true
Correct Answer: D
Rationale: Step-by-step rationale:
1. FOXO1 activates genes related to greater longevity by regulating stress responses and promoting cell survival.
2. Caloric restriction activates FOXO1 to promote cellular stress resistance and increase lifespan.
3. Increased insulin signaling deactivates FOXO1, leading to decreased stress resistance and potentially shorter lifespan.
4. Therefore, all the statements (A, B, and C) are true regarding the protein FOXO1. It plays a crucial role in longevity through gene regulation, is activated by caloric restriction, and is deactivated by increased insulin signaling.
Patients with a paralytic ileus typically have:
- A. Intravenous fluid replacement and a nasogastric tube connected to suction.
- B. Surgical correction of the problem.
- C. Endoscopic injection of botulinum toxin or esophageal dilation.
- D. Endoscopy to allow biopsy followed with broad-spectrum antibiotics.
Correct Answer: A
Rationale: Paralytic ileus is typically managed with intravenous fluids to correct electrolyte imbalances and a nasogastric tube to decompress the bowel.