How many of the following substances are secreted by exocrine glands.
mucus, thyroxine, saliva, earwax, insulin, oil, milk, digestive enzymes, melatonin and adrenalin :-

Options

A. Four
B. Five
C. Six
D. Seven

Answer

To determine how many of the listed substances are secreted by exocrine glands, we need to analyze each substance and classify it as either secreted by exocrine glands or endocrine glands.

### Step-by-step Solution:

1. **Identify the substances**: The substances given are:
- Mucus
- Thyroxine
- Saliva
- Earwax
- Insulin
- Oil
- Milk
- Digestive enzymes
- Melatonin
- Adrenalin

2. **Classify each substance**:
- **Mucus**: Secreted by exocrine glands (e.g., goblet cells in the respiratory and digestive tracts).
- **Thyroxine**: Secreted by endocrine glands (specifically the thyroid gland).
- **Saliva**: Secreted by exocrine glands (salivary glands).
- **Earwax**: Secreted by exocrine glands (ceruminous glands in the ear).
- **Insulin**: Secreted by endocrine glands (pancreas).
- **Oil**: Secreted by exocrine glands (sebaceous glands).
- **Milk**: Secreted by exocrine glands (mammary glands).
- **Digestive enzymes**: Secreted by exocrine glands (pancreas).
- **Melatonin**: Secreted by endocrine glands (pineal gland).
- **Adrenalin**: Secreted by endocrine glands (adrenal glands).

3. **Count the exocrine secretions**:
- Mucus: Exocrine
- Thyroxine: Endocrine
- Saliva: Exocrine
- Earwax: Exocrine
- Insulin: Endocrine
- Oil: Exocrine
- Milk: Exocrine
- Digestive enzymes: Exocrine
- Melatonin: Endocrine
- Adrenalin: Endocrine

The exocrine secretions are: Mucus, Saliva, Earwax, Oil, Milk, Digestive enzymes.

4. **Total count of exocrine secretions**: There are 6 substances that are secreted by exocrine glands.

### Final Answer:
**6 substances are secreted by exocrine glands.**

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