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Question #47462
The Question
The Ferguson reflex during parturition operates as a time-dependent positive feedback loop. If a localized anesthetic is administered that specifically blocks the afferent nerve fibers originating from the cervical stretch receptors during active labor, which of the following will be the most direct and immediate physiological consequence?
Options
- A.
A. The fetal adrenal cortex will cease cortisol secretion, preventing the necessary shift in the estrogen-to-progesterone ratio.
- B.
B. The maternal posterior pituitary will fail to release oxytocin, decoupling the neuroendocrine reflex arc and leading to dystocia.
- C.
C. The placenta will immediately halt the synthesis of prostaglandins, causing rapid relaxation of the myometrial smooth muscles.
- D.
D. The myometrial oxytocin receptors will undergo rapid desensitization due to the sudden absence of mechanical stimulation.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Parturition Neuroendocrine Reflex|Reflex Arc Latency|Progesterone/Estrogen Feedback
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'oxytocin causes contractions' but fail to dissect the dual nature of the 'neuroendocrine' reflex.
They must distinguish between the neural pathway (afferent signals from cervix to brain) and the endocrine pathway (efferent oxytocin from brain to uterus).
The trap lies in confusing the initiation of parturition (fetal cortisol/estrogen shift) with the maintenance and amplification of labor (maternal neural stretch reflex and oxytocin surge).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Reflex Arc Latency |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |