Anal Cancer: The Basics

Anal Cancer: The Basics

Christine Hill-Kayser, MD

Affiliation: The Abramson Cancer Center of the University of Pennsylvania

Last Modified: February 23, 2008

What is the anus?

The anus is an organ that lies at the end of the digestive tract below the rectum. It consists of two sections: the anal canal and the anus (or anal verge). The anal canal is a 3-4 cm long structure that lies between the anal sphincter (one of the muscles controlling bowel movements) just below the rectum and the anal verge which represents the transition point between the digestive tract and the skin on the outside of the body. Muscles within the anal canal and anus control the passage of stool from the rectum to outside the body.

What is anal cancer?

What are the adrenal glands?

Adrenal Cancer: The Basics

S. Jack Wei, MD
Affiliation: The Abramson Cancer Center of the University of Pennsylvania
Last Modified: October 28, 2008

What are the adrenal glands?

The adrenal glands are small glands that are located just above each kidney (they are sometimes called the suprarenal glands for that reason). They are triangular in shape and consist of several distinct parts:

The central part of the gland is called the adrenal medulla and produces the chemicals epinephrine (also called adrenaline) and norepinephrine. Both of these chemicals are involved in regulation of the nervous system. Epinephrine controls the short-term stress response (aka fight-or-flight response). While norepinephrine also plays a role in short-term stress response, it functions in regulating mood and attention, as well.