Answer:
fills with blood during arousal and causes an erection.
Step-by-step explanation:
The corpus spongiosum is a mass of tissue present in the under part of the penis (male sexual structure) that is actively responsible for erection of the penis. The corpus spongiosum, in conjunction with the corpus carvernosa works to maintain erection of the penis in males.
During sexual arousal, the corpus spongiosum, which surrounds the urethra (passage for urine and semen) helps keep the urethra open for semen to be released while the carvernosa becomes filled with blood. This constant flow of blood into the carvernosa makes the penis enlarge and assume an erect position.