Correct Answer: A

Rationale: The correct answer is A: The fovea. The fovea is the central focal point for incoming images because it contains a high concentration of cones, which are responsible for detailed central vision. Cones are essential for color vision and visual acuity. The macula, while important for central vision, refers to the area surrounding the fovea. The optic disk is where the optic nerve exits the eye, and it does not receive incoming images. The physiologic cup is a normal depression in the optic nerve head and is not involved in image reception. In conclusion, the fovea is the correct answer as it is the area with the highest visual acuity due to the dense concentration of cones.

Correct Answer: C

Rationale: The correct answer is C. During the secondary stage of syphilis, a rash marked by red or reddish-brown, penny-sized lesions over the palms and soles is a common clinical manifestation. This rash, known as a syphilitic rash, is a hallmark symptom of secondary syphilis. The rash can also appear on other parts of the body. It is important to note that syphilis progresses through distinct stages, and the secondary stage typically occurs a few weeks to a few months after the initial infection. Now, let's analyze why the other choices are incorrect: A: Absence of symptoms - This is incorrect as syphilis does present symptoms, especially during the secondary stage. B: Single painless lesion, chancre on the genital area - This is characteristic of the primary stage of syphilis, not the secondary stage. D: Poor muscle coordination - This symptom is associated with the late or tertiary stage of syphilis, not the secondary stage

Correct Answer: B

Rationale: The correct answer is B: Clonus. Clonus is a series of rhythmic, involuntary muscle contractions and relaxations that occur due to an abnormal response in the stretch reflex. In patients with neurological conditions like cerebral palsy, clonus is often observed due to increased muscle tone. Tremor (A) is a rhythmic shaking movement, not specifically associated with muscle contractions. Spasm (C) is a sudden, involuntary muscle contraction that is not typically rhythmic. Fasciculation (D) is a brief, spontaneous contraction of a small number of muscle fibers, not the rhythmic pattern seen in clonus.

Correct Answer: A

Rationale: The correct answer is A because in an older adult with an indwelling urinary catheter, a fever >100°F can be a sign of urinary tract infection (UTI) or urosepsis. Given her acute decline in mental status and fever, empiric antibiotic therapy is warranted to treat a potential infection. Choice B is incorrect because older adults with indwelling catheters are at increased risk for UTIs and bloodstream infections. Choice C is incorrect as obtaining a urine culture is important to confirm the diagnosis and guide appropriate antibiotic therapy. Choice D is incorrect as the duration of antibiotic treatment for a UTI is typically longer than 3 days.

Correct Answer: A

Rationale: The correct answer is A: It is not effective during an acute asthma attack. Salmeterol is a long-acting beta agonist used for maintenance therapy, not for acute attacks. It does not provide immediate relief. Choices B and C are incorrect because salmeterol's onset of action is not immediate, and it may take days to weeks to achieve full effect. Choice D is incorrect because salmeterol should not be used in children under 12 years old.