The forceful expulsion of semen from the urethra caused by contraction of smooth muscle in the urethra and skeletal muscle surrounding the base of the penis is called ________.

A) ejaculation
B) neutralization
C) physiological contracture
D) emission
E) orgasm

Ejaculation

The release of semen from the male reproductive system during sexual arousal.

Smooth Muscle

A type of muscle found in the walls of hollow organs, such as blood vessels and the digestive tract, that contracts involuntarily.

Urethra

The duct through which urine is discharged from the bladder to the outside of the body in both males and females and through which semen is discharged in males.