Correct sequence of layers from outer to inner in intestine of humans is

Options

A. Serosa, muscularis, mucosa, sub-mucosa
B. Serosa, mucosa, muscularis, sub-mucosa
C. Serosa, muscularis, sub-mucosa, mucosa
D. Serosa, mucosa, sub-mucosa, muscularis

Answer

To answer the question regarding the correct sequence of layers from outer to inner in the intestine of humans, we can break it down step by step:

### Step-by-Step Solution:

1. **Identify the Layers of the Intestine**: The intestine has four main layers that make up its structure. These layers are arranged from the outermost to the innermost.

2. **Outer Layer - Serosa**: The outermost layer of the intestine is called the **serosa**. This layer is composed of loose connective tissue and is responsible for protecting the intestine. It also contains blood vessels, lymphatics, and nerves.

3. **Second Layer - Muscularis**: Beneath the serosa is the **muscularis** layer. This layer is made up of smooth muscle tissue and is crucial for the process of peristalsis, which is the rhythmic contraction that helps move food through the digestive tract.

4. **Third Layer - Submucosa**: The next layer is the **submucosa**. This layer contains larger blood vessels and glands that secrete mucus, which aids in digestion and protects the intestinal lining.

5. **Innermost Layer - Mucosa**: The innermost layer is known as the **mucosa**. This layer is responsible for the absorption of nutrients and is divided into three types based on its structure and function.

### Final Sequence of Layers:
- **Serosa** (outermost)
- **Muscularis**
- **Submucosa**
- **Mucosa** (innermost)

### Answer:
The correct sequence of layers from outer to inner in the intestine of humans is:
1. Serosa
2. Muscularis
3. Submucosa
4. Mucosa

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