Contractile fibrils of muscles are called
(a) Neurofibrils
(b) Collagen fibres
(c) Myofibrils
(d) Yellow fibres

Options

A. Neurofibrils
B. Callogen fibres
C. Myofibrils
D. Yellow fibres.

Answer

To solve the question "Contractile fibrils of muscles are called," we will analyze each option provided.

1. **Understanding the Question**: The question asks for the specific term used to describe the contractile fibrils found in muscle tissue.

2. **Analyzing the Options**:
- **(a) Neurofibrils**: These are fibers found in nerve cells, not muscle cells. Hence, this option is incorrect.
- **(b) Collagen fibres**: These are structural proteins found in connective tissues, not specifically in muscle tissues. Therefore, this option is also incorrect.
- **(c) Myofibrils**: These are the contractile units of muscle fibers, composed of actin and myosin proteins. This option is likely correct.
- **(d) Yellow fibres**: These refer to elastic fibers found in connective tissues, not muscle contractile fibrils. Thus, this option is incorrect.

3. **Conclusion**: After analyzing all the options, the correct answer is **(c) Myofibrils**. Myofibrils are indeed the contractile fibrils of muscles.