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Question #47419
The Question
During parturition, the fetal ejection reflex initiates a positive feedback loop known as the Ferguson reflex. If a specific neuroendocrine disruption prevents the maternal hypothalamic-pituitary axis from responding to these initial cervical stretch signals, active labor is arrested. Which of the following accurately describes the anatomical and physiological basis of this disrupted step?
Options
- A.
The maternal hypothalamus fails to secrete oxytocin into the hypophyseal portal system, preventing its transport to the pars distalis for myometrial activation.
- B.
The maternal hypothalamus fails to generate action potentials, preventing the axonal transport and release of oxytocin from the pars nervosa, halting progressive myometrial contractions.
- C.
The placenta fails to synthesize oxytocin in response to cervical stretching, preventing the positive feedback loop required for strong endometrial contractions.
- D.
The fetal pituitary fails to release oxytocin into the maternal circulation, preventing the initial mild uterine contractions characteristic of the fetal ejection reflex.
Check Your Answer
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
Oxytocin|Ferguson_Reflex|Hypothalamic_Integration
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating the 'Human Reproduction' chapter (fetal ejection reflex) with the 'Chemical Coordination and Integration' chapter (hypothalamus-neurohypophysis axis).
The trap relies on Location Specificity (Pars Nervosa vs.
Pars Distalis) and Transport Mechanism (Axonal transport vs.
Hypophyseal portal system).
Students often incorrectly assume all hypothalamic hormones travel via the portal system to the anterior pituitary.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Action Potential Threshold Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |