Gross pathology of<unk> s, showing engorged blood vessels.<unk>  cushions are a part of normal human anatomy and become a pathological disease only when they experience abnormal changes. There are three main cushions present in the normal anal canal. These are located classically at left lateral, right anterior, and right posterior positions. They are composed of neither arteries nor veins, but blood vessels called sinusoids, connective tissue, and smooth muscle. Sinusoids do not have muscle tissue in their walls, as veins do. This set of blood vessels is known as the<unk> al plexus.<unk>  cushions are important for continence. They contribute to 15–20% of anal closure pressure at rest and protect the internal and external anal sphincter muscles during the passage of stool. When a person bears down, the intra-abdominal pressure grows, and<unk>  cushions increase in size, helping maintain anal closure.<unk>  symptoms are believed to result when these vascular structures slide downwards or when venous pressure is excessively increased. Increased internal and external anal sphincter pressure may also be involved in<unk>  symptoms. Two types of<unk> s occur: internals from the superior<unk> al plexus and externals from the inferior<unk> al plexus. The pectinate line divides the two regions.
Hemorrhoid
Anal cancer
Anal fissure
Anorectal varices
Hematocolpos
Pyometra
Rectitis
Anal fistula