ejaculation

Ejaculation is the process by which semen is discharged from the penis following sexual stimulation. In humans, the term most often refers to the male ejaculation; there is also female ejaculation, which involves the expulsion of fluid from the urethra in some individuals.

Physiologically, ejaculation is the final phase of the male sexual response and involves two closely coordinated processes: emission, where sperm and seminal fluids move into the posterior urethra, and expulsion, where rhythmic contractions of pelvic floor muscles expel semen through the urethra. Emission is mediated primarily by the sympathetic nervous system, while expulsion is driven by somatic pathways involving the pudendal nerves.

Typical semen volume ranges from about 1.5 to 5 milliliters, with a sperm concentration that varies widely among individuals. The process is usually accompanied by contraction of surrounding muscles and sometimes temporary changes in sensation and posture. Nocturnal emissions can occur during sleep as a normal part of male physiology.

Female ejaculation refers to a separate phenomenon reported by some individuals; it involves the expulsion of fluid from the urethral opening and is the subject of ongoing study and debate regarding its source and significance.

Common variations and disorders include premature ejaculation, delayed ejaculation, anejaculation, and retrograde ejaculation. Causes can be psychological, neurological, hormonal, anatomical, or medication-related. Evaluation typically includes history, physical examination, and, as indicated, hormonal testing or imaging. Treatments may involve behavioral therapy, counseling, pharmacotherapy for specific conditions, and management of any underlying medical issues.