A pair of triangular muscles in each segment, present on the either side of a cockroach heart, is of

Options

A. Alary muscles
B. Tergosternal muscles
C. intercostal muscles
D. Phrenic muscles

Answer

To solve the question regarding the pair of triangular muscles present on either side of a cockroach heart, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Muscles in Question**: The question specifically asks about a pair of triangular muscles located on either side of the cockroach heart.

2. **Consider the Options Provided**: The options given are:
- A) Allery muscles
- B) Turgosteronal muscles
- C) Intercostal muscles
- D) Phrenic muscles

3. **Analyze Each Option**:
- **Allery Muscles**: These muscles are triangular in shape and are located on either side of the cockroach heart. They play a crucial role in the pumping of the heart and the flow of hemolymph (the circulatory fluid in cockroaches).
- **Turgosteronal Muscles**: These are associated with the chitinous exoskeleton and not specifically related to the heart.
- **Intercostal Muscles**: These muscles are found in vertebrates and are not present in cockroaches.
- **Phrenic Muscles**: These are associated with the diaphragm in mammals and do not relate to the cockroach anatomy.

4. **Determine the Correct Answer**: Based on the analysis, the allery muscles are the correct answer as they are triangular, located on either side of the cockroach heart, and involved in the pumping mechanism.

5. **Final Answer**: The correct answer is **A) Allery muscles**.