pennis

Pennis is not a standard anatomical term; in medical and biological usage the external male genital organ is called the penis. When the form "pennis" appears, it is usually a misspelling or mistranslation of penis.

The penis functions in urination and sexual reproduction. It comprises a shaft ending in a glans, a foreskin (prepuce) in uncircumcised individuals, and three erectile tissues: two corpora cavernosa and one corpus spongiosum. The urethra runs through the middle, conveying urine and semen. Blood flow into the erectile tissues during arousal causes the penis to become erect, facilitating intercourse in many species.

Development and variation: the penis develops from the genital tubercle under androgen influence during fetal growth. At puberty, testosterone drives growth and secondary sexual characteristics. There is wide variation in size and form across individuals and species; size does not reliably predict sexual function or fertility in humans.

Health and safety: proper hygiene reduces infection risk. Conditions such as phimosis, balanitis, and penile cancer are uncommon but monitored. Erectile dysfunction, cardiovascular disease, and diabetes can affect function. Safe sex practices, regular medical checkups, and timely treatment of infections contribute to reproductive health.

Evolution and comparative biology: among mammals, some species have penile bones called bacula, while humans and many primates lack them. Penile morphology varies with mating systems, sexual selection, and reproductive strategies across species.

Etymology: penis comes from Latin, where it denotes the organ; "pennis" is not used in standard anatomical terminology. If you intended a different term or topic, please provide clarification.