Which of the following organs is not an excretory organ?

Options

A. Urethra
B. Kidneys
C. Lungs
D. Heart

Answer

To determine which organ is not an excretory organ, we will analyze the functions of the listed organs and identify their roles in waste removal from the body.

### Step-by-Step Solution:

1. **Identify the Excretory Organs**:
- The primary excretory organs in the human body include the kidneys, skin, lungs, and liver. Each of these organs plays a role in eliminating waste products.

2. **Analyze Each Organ**:
- **Skin**: The skin is the largest organ and helps in excretion by releasing sweat, which contains salts and other waste products.
- **Lungs**: The lungs excrete carbon dioxide, which is a waste product of cellular respiration.
- **Kidneys**: The kidneys are crucial for filtering blood and excreting nitrogenous wastes, primarily urea, through urine.
- **Liver**: The liver produces bile, which helps in the elimination of bile pigments and other waste products through the digestive system.

3. **Consider the Options**:
- The options include organs like kidneys, lungs, skin, and possibly others such as the heart or urethra.
- **Urethra**: While it is involved in the excretion of urine, it is not an organ that produces waste; it is a duct that allows waste to exit the body.
- **Heart**: The heart is primarily involved in circulation and does not have any role in excretion.

4. **Conclusion**:
- Among the organs mentioned, the heart is not an excretory organ. It is responsible for pumping blood throughout the body and does not participate in the removal of waste.

### Final Answer:
The organ that is not an excretory organ is the **heart**.

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