Because those words are what we call the beginning and ending of the reproductive phase of a woman. You might as well say "Why does life begin at conception and end at death?"
The lower end of female reproductive tract in pigs is not very different from humans. The reproductive system is conserved across all mammals.
The reproductive structures on a beetle are typically located on the abdomen. In males, the reproductive organs are usually found at the end of the abdomen, while in females, they are located nearer to the middle of the abdomen.
A sign of reproductive maturity is the start of menstruation in females.
hormones
Estrogen
epithelium
No
Ovulation.
sperm
reproductive
In males, the urinary system and reproductive system share the urethra, a tube that carries both urine and semen out of the body. In females, the urinary system and reproductive system are separate, but they are located close to each other in the pelvic area, which can sometimes lead to overlapping symptoms and conditions. Additionally, the proximity of the reproductive organs in females can make them susceptible to urinary tract infections.