What is the number of chambers in the heart of periplaneta americana ?

Options

A. 2 chambers
B. 4 chambers
C. 13 chambers
D. 11 chambers

Answer

To determine the number of chambers in the heart of Periplaneta americana (the cockroach), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organism**: Recognize that Periplaneta americana is the scientific name for the cockroach.

2. **Locate the Heart**: Understand that the heart of the cockroach is located mid-dorsally, meaning it is situated along the back of the organism.

3. **Understand the Structure of the Heart**: The heart of the cockroach is described as pulsatile, indicating that it functions by contracting and relaxing to pump hemolymph (the insect equivalent of blood).

4. **Count the Chambers**: The heart consists of 13 segmentally arranged funnel-shaped chambers. This means that there are 13 distinct sections in the heart.

5. **Note the Features of the Chambers**: Each of the 13 chambers (except the last one) has a pair of small lateral apertures called ostia. These ostia allow hemolymph to enter the heart from the pericardial sinus.

6. **Conclusion**: Based on the information gathered, we conclude that the heart of Periplaneta americana has **13 chambers**.

### Final Answer:
The number of chambers in the heart of Periplaneta americana is **13**.

---