Foetal ejection reflex in humans is induced by signals from

Options

A. Wastes accumulating in allantois
B. Colostrum secreted by mammary glands
C. Pressure exerted by amniotic fluid
D. Fully developed foetus and placenta

Answer

To answer the question regarding what induces the fetal ejection reflex in humans, we can break down the process step by step:

### Step-by-Step Solution:

1. **Understanding the Context**: The fetal ejection reflex is a physiological response that occurs during childbirth, also known as parturition. It is essential to know that this reflex is triggered by certain signals in the body.

2. **Identifying Potential Signals**: The question provides several options for what could induce the fetal ejection reflex:
- A) Signals from vestus accumulating in allantois
- B) Colostrum secreted by the mammary glands
- C) Pressure exerted by the amniotic fluid
- D) Fully developed fetus and placenta

3. **Analyzing Each Option**:
- **Option A**: Signals from vestus accumulating in allantois are not directly related to the fetal ejection reflex.
- **Option B**: Colostrum is the first form of milk produced by mammals but does not induce the fetal ejection reflex.
- **Option C**: Pressure from amniotic fluid may play a role in labor but is not the primary signal for the reflex.
- **Option D**: The fully developed fetus and placenta send signals to the maternal brain, which is crucial for inducing the fetal ejection reflex.

4. **Understanding the Mechanism**: When the fetus and placenta are fully developed, they send signals to the brain. This results in the release of oxytocin from the pituitary gland, which causes the uterus to contract vigorously, leading to the expulsion of the baby.

5. **Conclusion**: Based on the analysis, the correct answer is **Option D: Fully developed fetus and placenta**.

### Final Answer:
The fetal ejection reflex in humans is induced by signals from the fully developed fetus and placenta.

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