Drugs & toxin are mainly excreted by which process ?

Options

A. Ultra filtration
B. Digestion in the form of excreta
C. Tubular secretion
D. Diffusion

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the process through which drugs and toxins are mainly excreted from the body.

2. **Identifying the Options**: The options provided are:
- A) Ultrafiltration
- B) Excretion
- C) Tubular secretion
- D) Diffusion

3. **Analyzing Each Option**:
- **Ultrafiltration**: This is the initial process in the kidneys where blood is filtered to form urine, but it does not specifically refer to the excretion of drugs and toxins.
- **Excretion**: This is a general term for the elimination of waste from the body, but it does not specify the mechanism.
- **Tubular Secretion**: This is a specific process that occurs in the kidneys, particularly in the distal convoluted tubule (DCT), where substances such as drugs and toxins are actively secreted into the filtrate.
- **Diffusion**: This is a passive process that may occur for some substances but is not the main mechanism for the excretion of drugs and toxins.

4. **Correct Answer**: Based on the analysis, the correct answer is **C) Tubular secretion**. This process is crucial for the elimination of drugs and toxins from the body.

5. **Explanation of Tubular Secretion**: Tubular secretion involves the movement of substances from the blood into the tubular fluid in the kidneys. It occurs in the distal convoluted tubule (DCT) and is important for regulating the levels of various ions and eliminating waste products, including drugs like penicillin.