Question

1. during an erection, the penis becomes and stays rigid because arteries in the penis____ and veins in the penis____.a. constrict, dilateb. dilate, are compressedc. contract, expandd. compress veins, dilate

Explanation:

During an erection, the arteries in the penis dilate (widen) to allow more blood flow into the penis. At the same time, the veins in the penis are compressed. This compression of the veins restricts the outflow of blood from the penis. As a result, blood accumulates in the erectile tissues of the penis, causing it to become rigid.

• Option a: If arteries constricted (narrowed) and veins dilated, there would be less blood flow in and more blood flow out, which would not cause an erection.
• Option c: "Contract" for arteries is not the correct term (should be dilate), and "expand" for veins is not the correct description (veins are compressed).
• Option d: Compressing veins is part of the process, but arteries need to dilate, not the other way around as this option implies.

Answer:

B. Dilate, are compressed