Rectum

The final section of the large intestine, it plays a crucial role in the digestive system and waste elimination.

The rectum is a muscular tube that connects the sigmoid colon to the anal canal. Typically measuring about 12 to 15 centimeters in length, the rectum serves as a storage site for fecal matter before it is expelled from the body. It is lined with mucous membranes that assist in lubrication during the passage of stool.

Terminologia Anatomica

rectum

System

Digestive system

Function

The primary function of the rectum is to act as a temporary storage facility for feces produced by digestion. It gathers and collects waste material from the colon, detecting the presence of stool and signaling the need for its expulsion through nerve pathways. The rectum's muscles orchestrate a controlled process of defecation, ensuring that waste is expelled at appropriate times. Additionally, sensors in the rectal wall can distinguish between gas and solid waste, aiding in the prevention of accidental releases. This organ also plays a role in the absorption of certain substances, including some electrolytes and small amounts of water, which can contribute to maintaining the body's hydration levels.

Location

Situated at the lower end of the digestive tract, the rectum is located in the pelvis. It extends from the sigmoid colon above to the anal canal below. The rectum follows an S-shaped curve, adapting to the contours of the surrounding pelvic anatomy. It lies posterior to the bladder in males and the uterus in females, making its position unique in relation to other abdominal organs. Given its position, the rectum is also surrounded by a network of blood vessels and nerves that facilitate its functions and connect to other bodily systems, such as the nervous system and vascular system.

Did You Know?

The rectum can stretch significantly to accommodate varying amounts of fecal material.
During defecation, the rectum and anal canal experience a coordinated contraction and relaxation of muscles to allow for the passage of stool.
Rectal temperature measurement is often considered an accurate indicator of core body temperature.