Which of the following muscles are not under the voluntary control of nervous system ?

Options

A. Pharynx
B. Urinary bladder
C. Anterior end of oesophagus
D. Tongue

Answer

To determine which of the following muscles are not under the voluntary control of the nervous system, we need to identify the types of muscles and their control mechanisms. Here’s a step-by-step solution:

### Step 1: Understand Muscle Types
Muscles in the human body can be categorized into three main types:
- **Skeletal Muscles**: These are under voluntary control and are responsible for movement of the skeleton.
- **Smooth Muscles**: These are involuntary muscles found in the walls of hollow organs (like the urinary bladder, intestines, etc.) and are not under conscious control.
- **Cardiac Muscles**: These are also involuntary muscles found in the heart.

### Step 2: Analyze the Options
Now, we will analyze the given options one by one to identify which muscles are involuntary:

1. **Pharynx**: This is primarily composed of skeletal muscle, which is under voluntary control. Therefore, this option is not the answer.

2. **Urinary Bladder**: The muscles of the urinary bladder are smooth muscles, which are involuntary. This option is a strong candidate for the answer.

3. **Anterior End of Esophagus**: This part of the esophagus contains skeletal muscle and is under voluntary control. Hence, this option is not the answer.

4. **Tongue**: The tongue is primarily made up of skeletal muscles, which are also under voluntary control. Thus, this option is not the answer.

### Step 3: Conclusion
From the analysis, the only muscle that is not under voluntary control of the nervous system is the **Urinary Bladder**.

### Final Answer:
**Urinary Bladder** is the muscle that is not under the voluntary control of the nervous system.

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