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 muscles are not under the voluntary control of the nervous system, we need to classify the types of muscles based on 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:
1. **Skeletal Muscles**: These are under voluntary control and are responsible for movements of the skeleton.
2. **Smooth Muscles**: These are not under voluntary control and are found in the walls of hollow organs (like the intestines and blood vessels).
3. **Cardiac Muscles**: These are also not under voluntary control and are found in the heart.

### Step 2: Identify the Options
From the question, we need to identify which of the listed muscles are smooth or cardiac muscles, as these are not under voluntary control. The options mentioned include:
- Farynx
- Urinary Bladder
- Anterior End of the Esophagus
- Mouth Surrounding Part of the Esophagus
- Tongue

### Step 3: Analyze Each Option
- **Farynx**: Involves both voluntary and involuntary muscles, but primarily under voluntary control for swallowing.
- **Urinary Bladder**: Contains smooth muscle, which is not under voluntary control.
- **Anterior End of the Esophagus**: Primarily composed of skeletal muscle (voluntary control).
- **Mouth Surrounding Part of the Esophagus**: Skeletal muscle (voluntary control).
- **Tongue**: Composed of skeletal muscle (voluntary control).

### Step 4: Conclusion
From the analysis, the **Urinary Bladder** is the only option that contains smooth muscle and is not under voluntary control of the nervous system.

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

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