Defaecation-

Options

A. is a voluntary process
B. is carried out by a mass peristaltic movement
C. Both
D. is otherwise known as ingestion

Answer

### Step-by-Step Solution for Defecation

1. **Definition of Defecation**:
- Defecation is the process of eliminating waste material from the digestive tract through the anus. It is a crucial part of the digestive system.

2. **Nature of the Process**:
- Defecation is primarily a **voluntary process**. This means that while the body has reflex mechanisms to initiate it, individuals can control when to defecate.

3. **Role of Mass Peristalsis**:
- The process involves **mass peristalsis**, which is a series of wave-like muscle contractions that move food through the digestive tract. This movement helps push the fecal matter into the rectum.

4. **Storage in the Rectum**:
- Fecal matter is stored in the **rectum** until it is ready to be expelled. The rectum acts as a temporary storage site for the waste.

5. **Ejection of Fecal Matter**:
- When the rectum is full, stretch receptors signal the brain, leading to the urge to defecate. The body then initiates the process to expel the fecal matter, often referred to as the **ejection of fecal matter**.

6. **Final Control**:
- The individual can choose to either proceed with defecation or delay it, showcasing the voluntary control over this process.

### Summary of Key Points:
- Defecation is a voluntary process.
- It involves mass peristalsis to move fecal matter to the rectum.
- The rectum stores fecal matter until ejection.
- The process is controlled by both involuntary reflexes and voluntary actions.