Which of the statements is incorrect w.r.t. melatonin hormone ?

Options

A. Shows diumal variation
B. Antigonadial hormone
C. Secreted by pineal body
D. Poorly vascularized

Answer

To determine which statement about the melatonin hormone is incorrect, we will analyze each of the provided statements step by step.

### Step 1: Identify the Source of Melatonin
- **Statement Analysis**: Melatonin is secreted by the pineal gland.
- **Conclusion**: This statement is correct. The pineal gland, located in the brain, is responsible for the production and release of melatonin.

### Step 2: Understand the Role of Melatonin in Sleep-Wake Cycle
- **Statement Analysis**: Melatonin plays an important role in the regulation of the sleep-wake cycle.
- **Conclusion**: This statement is also correct. Melatonin levels rise in the evening and fall in the morning, helping to regulate our circadian rhythms and sleep patterns.

### Step 3: Examine Melatonin's Influence on Body Functions
- **Statement Analysis**: Melatonin influences metabolism and body temperature.
- **Conclusion**: This statement is correct. Melatonin has various functions, including the regulation of metabolism and body temperature.

### Step 4: Evaluate the Vascularization of the Pineal Gland
- **Statement Analysis**: The pineal gland is poorly vascularized.
- **Conclusion**: This statement is incorrect. The pineal gland is actually well vascularized, allowing for efficient hormone secretion into the bloodstream.

### Final Conclusion
Based on the analysis of each statement, the incorrect statement regarding melatonin is that it is "poorly vascularized." Therefore, the correct answer is the fourth option.