Which of the given option is incorrect about spleen ?

Options

A. It is the graveyard of erythrocytes .
B. It receives only oxygenated blood.
C. It helps in filteration of blood.
D. It is primary lymphoid organ.

Answer

To solve the question regarding which statement about the spleen is incorrect, we will analyze each of the provided statements one by one.

### Step-by-Step Solution:

1. **Statement 1: "It is the graveyard of erythrocytes."**
- This statement is **correct**. The spleen is known as the graveyard for red blood cells (erythrocytes) because it is responsible for the removal and destruction of old and damaged RBCs. The average lifespan of an erythrocyte is about 120 days, after which they are filtered out and destroyed in the spleen.

2. **Statement 2: "It receives only oxygenated blood."**
- This statement is **incorrect**. The spleen receives blood from the splenic artery, which carries both oxygenated and deoxygenated blood. While the spleen does play a role in filtering blood, it does not exclusively receive oxygenated blood.

3. **Statement 3: "It helps in filtration of blood."**
- This statement is **correct**. The spleen has a significant role in filtering the blood, particularly in removing old and damaged red blood cells, as well as pathogens and debris.

4. **Statement 4: "It is a primary lymphoid organ."**
- This statement is **incorrect**. The spleen is classified as a secondary lymphoid organ. Primary lymphoid organs include the thymus and bone marrow, where lymphocytes are produced and mature. The spleen, on the other hand, is involved in the immune response and filtering blood.

### Conclusion:
After analyzing all the statements, we find that the incorrect statement about the spleen is **Statement 2: "It receives only oxygenated blood."**

### Final Answer:
The incorrect statement about the spleen is **Option D: "It is a primary lymphoid organ."**

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