Secretion of saliva can be stimulated by -

Options

A. Sight of food
B. Smell of food
C. Presence of food in oral cavity
D. All

Answer

To answer the question, "Secretion of saliva can be stimulated by -", we can break down the information as follows:

### Step-by-Step Solution:

1. **Understanding Saliva Secretion**: Saliva is produced by salivary glands in the oral cavity. The secretion of saliva is a crucial part of the digestive process as it contains enzymes that begin the breakdown of food.

2. **Stimuli for Saliva Secretion**: The secretion of saliva can be stimulated by various factors. The primary stimuli include:
- **Food Presence**: When food enters the mouth, it directly stimulates the salivary glands to secrete saliva. This is a reflex action that prepares the digestive system for processing food.
- **Smell of Food**: The aroma of food can trigger the salivary glands even before food is consumed. This is due to the brain's response to the smell, which anticipates eating and stimulates saliva production.
- **Taste of Food**: The taste sensations (sweet, sour, salty, bitter, umami) can also stimulate saliva secretion as the taste buds send signals to the salivary glands.

3. **Other Factors**: Other factors that can stimulate saliva secretion include:
- **Thoughts of Food**: Just thinking about food can stimulate saliva production due to psychological factors.
- **Certain Medications or Substances**: Some medications or substances can increase saliva production as a side effect.

### Final Answer:
Secretion of saliva can be stimulated by the presence of food, the smell of food, and the taste of food.

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