Which of the following is the correct statement about the circulatory system of cockroach

Options

A. In has closed type of circulatory sytem
B. It has a compicated type of circulatory system
C. It has 13-chambered heart with a pair of ostia in each chamber
D. It takes place without participation of tissues

Answer

To answer the question regarding the circulatory system of a cockroach, we will analyze the provided options and the characteristics of the cockroach's circulatory system step by step.

### Step-by-Step Solution:

1. **Understanding the Circulatory System Type**:
- The circulatory system of a cockroach is classified as an open type of circulatory system. This means that the blood is not confined exclusively to blood vessels but instead flows freely through cavities called hemocoels.

**Hint**: Remember that open circulatory systems are characterized by blood bathing the organs directly.

2. **Heart Structure**:
- The cockroach has a heart that is elongated, thick, muscular, and cuboidal. It is important to note that the heart of a cockroach is not three-chambered; rather, it is a **13-chambered heart**.

**Hint**: Focus on the number of chambers in the cockroach heart, which is a key distinguishing feature.

3. **Function of Ostia**:
- Each chamber of the cockroach's heart has a pair of openings called ostia. These ostia allow the entry of hemolymph (the blood equivalent in insects) into the heart chambers from the dorsal sinus.

**Hint**: Ostia are crucial for the heart's function in an open circulatory system.

4. **Blood Flow Direction**:
- The heart contracts in a posterior-anterior direction, meaning it pumps the hemolymph from the back (posterior) to the front (anterior) of the body.

**Hint**: Remember the direction of blood flow during heart contraction.

5. **Role of Muscles**:
- The contraction of the heart is facilitated by muscular contractions, specifically the contraction of the heart wall and associated muscles.

**Hint**: Muscular contractions are essential for the movement of hemolymph in the cockroach.

6. **Tissue Participation**:
- The circulatory process in cockroaches involves direct contact of hemolymph with tissues, meaning that the blood does participate in the exchange of nutrients and gases with tissues.

**Hint**: Open circulatory systems allow for direct interaction between blood and tissues.

### Conclusion:
Based on the analysis, the correct statement about the circulatory system of the cockroach is that it has a **13-chambered heart with a pair of ostia in each chamber**. The other options provided are incorrect as they misrepresent the type of circulatory system and the structure of the heart.

### Final Answer:
The correct statement is: **It has a 13-chambered heart with a pair of ostia in each chamber.**