Read the following statements and find out the incorrect statements.
a. Heart is situated in the thoracic cavity, is between the two lungs, slightly tilted to the right.
b. Heart has the size of a clenched fist.
(c ) Heart is protected by double walled membranous bag, pericardium, enclosed the pericardial fluid.
d. Human heart has four chambers, two relatively larger upper chambers called atria and two smaller lower chambers called ventricles.
e. A thick muscular wall called the inter-atrial septum separtes the right and the left atria, whereas a thinwalled, the inter-ventricular septum, separtes the left and right ventricles.

Options

A. a,d and e
B. b,c and d
C. b,c and e
D. a and d

Explanation

To identify the incorrect statements from the provided options regarding the human heart, let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement A**: "Heart is situated in the thoracic cavity, is between the two lungs, slightly tilted to the right."
- The heart is indeed located in the thoracic cavity and is positioned between the two lungs. However, it is slightly tilted to the left, not the right. Therefore, this statement is **incorrect**.

2. **Statement B**: "Heart has the size of a clenched fist."
- This statement is correct. The size of the human heart is approximately that of a clenched fist. Thus, this statement is **correct**.

3. **Statement C**: "Heart is protected by a double walled membranous bag, pericardium, enclosed the pericardial fluid."
- This statement is also correct. The heart is indeed protected by a double-walled structure known as the pericardium, which contains pericardial fluid. Therefore, this statement is **correct**.

4. **Statement D**: "Human heart has four chambers, two relatively larger upper chambers called atria and two smaller lower chambers called ventricles."
- This statement is incorrect. The upper chambers are called atria (plural of atrium), which are smaller than the lower chambers. The lower chambers are the ventricles, which are larger. Thus, this statement is **incorrect**.

5. **Statement E**: "A thick muscular wall called the inter-atrial septum separates the right and the left atria, whereas a thin-walled, the inter-ventricular septum, separates the left and right ventricles."
- This statement is incorrect in its description of the septa. The wall separating the atria is called the inter-atrial septum, which is indeed thin, while the wall separating the ventricles is the interventricular septum, which is thicker. Therefore, this statement is **incorrect**.

### Summary of Incorrect Statements:
- **Incorrect Statements**: A, D, and E.

### Final Answer:
The incorrect statements are A, D, and E.

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