Ejaculation is attained by an involuntary contraction of muscles and vessels that propel semen from the human body. The exact same tube that may be employed for ejaculation, called the urethra, is also useful for urination (peeing). This permits the sheath to extend out along with the penis to straighten. https://hectors1zy1.blogoscience.com/41810343/the-fact-about-penis-that-no-one-is-suggesting