Anus

Definition

The anus is the terminal end of the digestive tract through which feces are expelled from the body. It consists of muscles that control the release of waste material.

5 Must Know Facts For Your Next Test

1. The anus is controlled by both voluntary and involuntary muscles.
2. It plays a crucial role in the excretion process by allowing waste to leave the body.
3. The internal anal sphincter is composed of smooth muscle, while the external anal sphincter is skeletal muscle.
4. In many animals, including humans, it also serves as a sensory organ to detect rectal contents.
5. Proper functioning of the anus is essential for maintaining continence and preventing fecal incontinence.

Review Questions

• What types of muscles control the function of the anus?
• Why is the anus important in the digestive system?
• Differentiate between internal and external anal sphincters.

Related terms

rectum: The final section of the large intestine where feces are stored before being expelled through the anus.

sphincter: A circular muscle that constricts or dilates to regulate passage through an opening in the body.

feces: Solid waste matter discharged from the bowels after digestion has taken place.