Nokea
Regarding carbohydrate metabolism:
- A. glucokinase is increased in starvation
- B. the breakdown of glycogen is called glycolysis
- C. the direct oxidative pathway involves the breakdown of glucose through triose
- D. the conversion of pyruvate to acetyl-CoA is irreversible
Correct Answer: D
Rationale: Correct Answer: D - The conversion of pyruvate to acetyl-CoA is irreversible because it is catalyzed by the enzyme pyruvate dehydrogenase. This step is a key regulatory point in carbohydrate metabolism as it commits pyruvate to enter the citric acid cycle for further energy production. Reversing this step would disrupt the normal flow of metabolic pathways.
Summary of other choices:
A: Glucokinase is not increased in starvation; it regulates glucose uptake in the liver.
B: The breakdown of glycogen is called glycogenolysis, not glycolysis which is the breakdown of glucose.
C: The direct oxidative pathway involves the breakdown of glucose through glycolysis, not triose.
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A deficiency of dietary iodine:
- A. lowers plasma calcium levels.
- B. causes low blood volume and shock.
- C. decreases the synthesis of calcitonin.
- D. causes a goiter.
Correct Answer: D
Rationale: The correct answer is D because a deficiency of dietary iodine leads to an insufficient production of thyroid hormones, which can result in the enlargement of the thyroid gland, known as a goiter. This is due to the thyroid gland working harder to try to produce more hormones.
A, B, and C are incorrect because a deficiency of dietary iodine does not directly affect plasma calcium levels, blood volume, or the synthesis of calcitonin. These are functions that are primarily regulated by other hormones and factors in the body, not by iodine deficiency.
Mr. R, a 52-year-old patient with hyperthyroidism, is experiencing a thyroid storm. Which of the following symptoms would indicate the need for immediate intervention?
- A. Hypothermia
- B. Low blood pressure
- C. Severe tachycardia
- D. Weight gain
Correct Answer: C
Rationale: Severe tachycardia is a hallmark of thyroid storm and requires immediate intervention to prevent life-threatening complications such as heart failure or stroke.
Following the teaching of foot care to a diabetic patient, the nurse determines that additional instruction is needed when the patient makes which statement?
- A. I should wash my feet daily with soap and warm water.
- B. I should always wear shoes to protect my feet from injury.
- C. If my feet are cold, I should wear socks instead of using a heating pad.
- D. I'll know if I have sores or lesions on my feet because they will be painful.
Correct Answer: D
Rationale: Patients with diabetes may not feel pain due to neuropathy, so they must regularly inspect their feet for sores or lesions.
Which is INCORRECT regarding nerve supply to the gut?
- A. the blood vessels are known to have enteric, parasympathetic and sympathetic innervation
- B. the myenteric plexus lies between the longitudinal and circular muscle layers
- C. parasympathetic supply is via vagal and sacral nerve
- D. sympathetic supply is often inhibitory on cholinergic postganglionic fibres
Correct Answer: A
Rationale: The correct answer is A because blood vessels in the gut are primarily innervated by sympathetic and parasympathetic fibers, not by enteric nerves. Enteric nerves are confined to the gastrointestinal tract itself and are responsible for regulating gut motility, secretion, and blood flow. Sympathetic innervation typically causes vasoconstriction, while parasympathetic innervation promotes vasodilation. The myenteric plexus (Auerbach's plexus) lies between the longitudinal and circular muscle layers, regulating gut motility. Parasympathetic supply to the gut is mainly through the vagus nerve (cranial nerve X) and sacral nerves (pelvic splanchnic nerves). Sympathetic supply can either be inhibitory or excitatory, but generally, sympathetic fibers are inhibitory on cholinergic postganglionic fibers in the gut.
Why is the posterior pituitary gland called the neurohypophysis?
- A. The posterior pituitary gland is an extension of the hypothalamus.
- B. The neurohypophysis secretes releasing hormones.
- C. The posterior pituitary gland secretes hormones that regulate adenohypophyseal function.
- D. The posterior pituitary gland secretes releasing hormones.
Correct Answer: A
Rationale: The correct answer is A because the posterior pituitary gland is an extension of the hypothalamus. The hypothalamus produces hormones that are stored and released by the posterior pituitary gland. This connection between the two structures allows for direct neural control over hormone release.
Option B is incorrect because the neurohypophysis does not secrete releasing hormones; rather, it releases hormones produced by the hypothalamus. Option C is incorrect because the posterior pituitary gland does not regulate adenohypophyseal function; instead, it stores and releases hormones produced by the hypothalamus. Option D is incorrect because the posterior pituitary gland does not secrete releasing hormones; it releases hormones produced by the hypothalamus.