Correct Answer: C

Rationale: Given the patient's presentation of itching, anorectal pain, and tenesmus, along with rectal examination findings of generalized tenderness without prostate abnormalities, proctitis is the most likely diagnosis. Proctitis is inflammation of the rectal lining and is commonly associated with symptoms such as rectal pain, itching, tenesmus (feeling of incomplete defecation), and sometimes rectal bleeding. It can have various causes, including sexually transmitted infections (such as gonorrhea, chlamydia), inflammatory bowel disease, radiation therapy, or trauma.

Correct Answer: A

Rationale: A hyperresonant percussion note is a more intense and booming sound heard during percussion of the thorax. This can occur when there is an increased amount of air present in the chest cavity. In the case of a large pneumothorax, which is the presence of air in the pleural space causing partial or complete collapse of the lung, the percussion note would be hyperresonant due to the increased air content in the thoracic cavity. Lobar pneumonia, pleural effusion, and empyema would typically produce dull or flat percussion notes due to the presence of fluid or solid material in the pleural space.

Correct Answer: C

Rationale: Diplopia occurring when one eye is covered is a condition known as monocular diplopia. This symptom is typically not caused by problems within the eye itself, such as irregularities in the cornea or lens. Instead, monocular diplopia with one eye covered is more likely to be an indication of a neurological issue, often involving the brainstem. Lesions or damage in the brainstem can disrupt the normal coordination of eye movements, leading to the perception of double vision when one eye is closed. Weakness of CN III (oculomotor nerve) or CN IV (trochlear nerve) may cause diplopia when both eyes are open, but it would not typically manifest as monocular diplopia.

Correct Answer: C

Rationale: The pectoral lymph node group, also known as the Level III lymph nodes, is the most commonly involved in breast cancer metastasis. These lymph nodes are located along the lower border of the pectoralis minor muscle and are an important regional drainage site for breast tissue. Therefore, in cases of breast cancer, the pectoral lymph nodes are frequently affected due to their proximity to the breast tissue.

Correct Answer: C

Rationale: Splitting of the second heart sound is when the aortic and pulmonic valves close at slightly different times, resulting in two distinct components to the sound. This split is best heard over the apex of the heart, typically with the diaphragm of the stethoscope. The aortic component is heard first and represents closure of the aortic valve, followed by the pulmonic component, representing closure of the pulmonic valve. The split can narrow during inspiration and widen during expiration, which is important to keep in mind during assessment.