Select the incorrect statement w.r.t humans.

Options

A. Starch and fat reach stomach totally undigested from oral cavity.
B. Dentition is heterodont,diphydont and thecodont
C. Muscularis externa mainly consists of outer longitudinal and inner circular muscle layer
D. Intestinal gland are present mainly in mucosal layer except Brunner`s glands

Answer

To solve the question of selecting the incorrect statement with respect to humans, we will analyze each statement provided in the video transcript step by step.

### Step-by-Step Solution:

1. **Statement Analysis:**
- **Statement 1:** "Starch and fat rich reach stomach totally undigested from oral cavity."
- This statement is incorrect. In the oral cavity, starch begins to be digested by the enzyme amylase (found in saliva), converting it into maltose. However, fats do not undergo significant digestion in the mouth.

2. **Statement 2:** "Dentition is heterodont, diaphyodont, and thecodont."
- This statement is correct. Humans have heterodont dentition (different types of teeth), are diaphyodont (two sets of teeth in a lifetime), and thecodont (teeth are set in sockets).

3. **Statement 3:** "Muscularis externa mainly consists of outer longitudinal and inner circular muscle layer."
- This statement is incorrect. The muscularis externa of the stomach consists of three layers: an outer longitudinal layer, a middle circular layer, and an inner oblique layer. Therefore, this statement does not accurately describe the muscularis externa.

4. **Statement 4:** "Intestinal glands are mainly present in mucosal layer except Brunner's gland."
- This statement is correct. Most intestinal glands are located in the mucosal layer, while Brunner's glands are located in the submucosal layer of the duodenum.

### Conclusion:
The incorrect statements are:
- Statement 1: "Starch and fat rich reach stomach totally undigested from oral cavity."
- Statement 3: "Muscularis externa mainly consists of outer longitudinal and inner circular muscle layer."

However, since the question asks for a single incorrect statement, the answer is **Statement 3**.

### Final Answer:
**The incorrect statement is: "Muscularis externa mainly consists of outer longitudinal and inner circular muscle layer."**

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