Which of the following statements describes an active cellular membrane exchange process?
- A. Sodium moving out of cells and potassium moving into cells
- B. The movement of water from an area of low solute concentration to an area of high solute concentration
- C. The movement of insulin using a protein to travel across the cell membrane
- D. Oxygen moving across the pulmonary capillaries to an area of high carbon dioxide
Correct Answer: A
Rationale: The correct answer is A. In active transport, energy is expended to move substances against their concentration gradient. Sodium moving out of cells and potassium moving into cells is an example of active transport because it requires energy to pump these ions across the cell membrane against their concentration gradients. Choices B, C, and D describe passive processes where substances move along their concentration gradients without the input of energy.
You may also like to solve these questions
In a patient with a subconjunctival hemorrhage due to allergic rhinitis, which statement is accurate?
- A. The hemorrhage will resolve without treatment within 2 weeks.
- B. The patient should be referred for immediate ophthalmologic examination.
- C. Oral antihistamines should be started to prevent further complications.
- D. Topical corticosteroids may be considered to reduce inflammation.
Correct Answer: A
Rationale: In a patient with a subconjunctival hemorrhage secondary to allergic rhinitis, the hemorrhage is typically self-limiting and will resolve on its own within 2 weeks without the need for specific treatment. Referring the patient for immediate ophthalmologic examination is not necessary unless there are other concerning symptoms. Starting oral antihistamines may help manage the underlying allergic rhinitis but is not specifically indicated for the hemorrhage. Topical corticosteroids are not routinely prescribed for subconjunctival hemorrhage as they may have limited benefit and could potentially cause complications.
What is a cause of the crystallization within the synovial fluid of the joint affected by gouty arthritis?
- A. Destruction of proteoglycans
- B. Underexcretion of uric acid
- C. Overexcretion of uric acid
- D. Increased absorption of uric acid
Correct Answer: B
Rationale: The correct answer is B: Underexcretion of uric acid. In gouty arthritis, the crystallization within the synovial fluid of the affected joint is caused by the underexcretion of uric acid, leading to the accumulation and subsequent crystallization of urate crystals. Choice A, destruction of proteoglycans, is incorrect as it is not directly related to the crystallization process in gouty arthritis. Choice C, overexcretion of uric acid, is incorrect because gout is primarily associated with underexcretion or decreased excretion of uric acid rather than overexcretion. Choice D, increased absorption of uric acid, is also incorrect as the primary issue in gouty arthritis is the body's inability to properly eliminate uric acid.
What can multiple dark bands on the nails indicate?
- A. They are considered a normal variant.
- B. They can be associated with malignant melanoma.
- C. They are indicative of a nail fungus.
- D. They are associated with aging.
Correct Answer: B
Rationale: Multiple dark bands on the nails can be associated with malignant melanoma, a serious type of skin cancer. While dark bands on the nails can sometimes be a normal variant, they should not be ignored as they could also be a sign of a serious condition like melanoma. Nail fungus typically presents with different symptoms such as thickened, discolored, or brittle nails. Dark bands on the nails are not directly associated with aging.
After a 27-year-old woman with epilepsy had a generalized seizure, she feels tired and falls asleep. This is:
- A. an ominous sign.
- B. normal and termed the postictal period.
- C. a reflection of an underlying brain tumor.
- D. only worrisome if there are focal neurologic deficits after.
Correct Answer: B
Rationale: The correct answer is B: normal and termed the postictal period. The postictal period is a common phase following a seizure where the individual may experience fatigue, confusion, or sleepiness. It is a normal part of the seizure event and does not necessarily indicate a serious issue. Choice A is incorrect because feeling tired and falling asleep after a seizure is not an ominous sign but rather a typical postictal symptom. Choice C is incorrect as there is no indication in the scenario provided that links the symptoms to an underlying brain tumor. Choice D is incorrect because the absence of focal neurologic deficits does not make the postictal period worrisome.
Which of the following women is at highest risk for the development of endometrial cancer?
- A. A 50-year-old postmenopausal woman with a history of high-risk human papillomavirus
- B. A 45-year-old woman who is obese and has a menstrual pattern consisting of periods of amenorrhea and infrequent periods
- C. A 40-year-old woman who is overweight and has hypertension
- D. A 55-year-old woman who smokes
Correct Answer: B
Rationale: The correct answer is a 45-year-old woman who is obese and has a menstrual pattern consisting of periods of amenorrhea and infrequent periods. Obesity and prolonged exposure to estrogen unopposed by progesterone due to infrequent ovulation are significant risk factors for endometrial cancer. Choices A, C, and D do not directly correlate with the increased risk of endometrial cancer. Postmenopausal status alone (Choice A), overweight with hypertension (Choice C), and smoking (Choice D) are not the primary risk factors for endometrial cancer.