Vigorous contraction of the uterus during parturition are induced by :

Options

A. neuroendocrine mechanism
B. embryo pushing out
C. endocrine mechanism
D. uterine fluids

Answer

**Step-by-Step Solution:**

1. **Understanding Parturition**: Parturition refers to the process of childbirth, which involves the expulsion of the fetus from the uterus. This process is characterized by vigorous contractions of the uterine muscles.

2. **Role of Hormones**: During parturition, certain hormones play a crucial role in stimulating these contractions. The most significant hormone involved is oxytocin.

3. **Source of Oxytocin**: Oxytocin is produced in the hypothalamus and is released into the bloodstream by the posterior pituitary gland. The release of oxytocin is triggered by signals from the brain.

4. **Neuroendocrine Mechanism**: The mechanism that induces the release of oxytocin during parturition is known as the neuroendocrine mechanism. This involves the nervous system (neurons) and the endocrine system (hormones).

5. **Contraction Induction**: Once oxytocin is released into the bloodstream, it acts on the uterine muscles, promoting strong contractions that help in the delivery of the baby.

6. **Conclusion**: Therefore, the vigorous contractions of the uterus during parturition are induced primarily by the neuroendocrine mechanism, specifically through the action of oxytocin.

**Final Answer**: Vigorous contraction of the uterus during parturition is induced by the neuroendocrine mechanism, which involves the release of oxytocin from the pituitary gland.

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