Final answer:
The peniiis is the external male reproductive organ that can perform both reproductive functions, such as delivering sperm, and excretion of urine. It is covered by the foreskin, which protects and lubricates the glans peniiis. The corpora cavernosa and corpus spongiosum are critical for erection during sexual arousal.
Step-by-step explanation:
The peniiis is the external male reproductive organ responsible for the delivery of sperm to the female reproductive tract, a process known as intromission. Covered by skin known as the epithelium, it is capable of both sexual reproduction and excretion of urine. The tip of the peniiis, the glans peniiis, is sensitive and covered by the foreskin in uncircumcised males. Connected to the glans is the foreskin or prepuce which protects and lubricates the glans. It is attached to the peniiis via an area called the frenulum.
During sexual arousal, the peniiis fills with blood, causing it to become erect. This erect state is crucial for the act of sexual intercourse, allowing the peniiis to penetrate the vagina and deposit semen. This process is facilitated by the corpora cavernosa and the corpus spongiosum, chambers of erectile tissue. Testosterone plays a vital role in maintaining sexual function and in the occurrence of puberty changes.