What is Human anus?
{{Infobox anatomy|Name=Human anus|Latin=anus|Image=File:Human_anus_ver_1.jpeg|Caption=A woman's anus, without pubic hair|Image2=Tractus intestinalis anus.svg|Caption2=Photo of [[Gastrointestinal tract|digestive tract]], with anus shown|Width=|precursor=[[Proctodeum]]|system=[[Alimentary system|Alimentary]]|Artery=[[Inferior rectal artery]]|vein=[[Inferior rectal vein]]|nerve=[[Inferior rectal nerves]], [[pudendal nerve]]|lymph=[[Superficial inguinal lymph nodes]]}} In [[Human|humans]], the '''anus''' ([[plural]]: anuses) is the outer opening of the [[rectum]] (where the poop is stored), found between the butcheeks ([[buttocks]]). Its main job is to let poo leave the body during pooping. The anus has two muscles called '''sphincters''' that control this process: # The '''inner sphincter''' (works automatically, without you thinking about it). # The '''outer sphincter''' (you can control this one). These muscles are normally tight to keep the anus closed, but they relax when you need to poop. Above the anus is an area called the '''perineum''', which is also below the [[vulva]] (in females) or the [[scrotum]] (in males). Because the anus comes into contact with poo, it can be affected by several medical conditions, such as [[Hemorrhoid|hemorrhoids]] (piles). The anus is also a place where [[Infection|infections]] and other problems, including [[anal cancer]], can happen. The anus can be involved in [[Human sexual activity|sexual activity]], such as [[anal sex]]. People have different opinions about [[anal sex]], and in some countries, it is even illegal. The anus is often seen as a [[taboo]] body part and is referred to by many [[slang]] terms, which are usually vulgar. Anal sex can also spread certain [[Sexually transmitted disease|sexually transmitted infections]] (STIs), such as [[HIV]]/[[AIDS]] and [[anal warts.]] [[File:Human_anus-en.svg|thumb|A front-view cut of the human anus.]] The anus is the last part of the [[digestive system]], connecting directly to the [[rectum]] and passing through the pelvic f