How does our body work?
The penis is part of the male reproductive or sexual system, which includes body parts like the scrotum and testicles. In order to understand how the penis works, it can help to think of it in two parts – the outside and the inside.
On the outside, the shaft of the penis is covered by a thin layer of skin that is loose when un-aroused or flaccid. On the inside, the urethra runs through the middle of the penis, a tube that ends at the top of the head, or glans penis, where a slit-like vertical opening can be seen. Essentially, the urethra connects the bladder and the prostate gland with the end of the penis and plays a key role in men’s sexual health.
The internal sphincter, a muscle located at the base of the bladder,stops urine and semen from leaving the penis at the same time. When an orgasm occurs, the muscle shuts tightly to prevent urine from passing through the urethra at the same time, and to prevent sperm from passing ‘backwards’ into the bladder.