Quiz: Ferguson Reflex in Labor — 5 questions

1. What effect does increased uterine oxytocin-receptor density have during labor?

A. It makes the uterus less responsive to oxytocin

B. It makes the uterus more responsive to oxytocin

C. It prevents oxytocin from reaching the uterine muscle

D. It changes uterine contractions into voluntary maternal movements

Answer: (B)

Explanation

A higher density of oxytocin receptors allows the uterus to respond more strongly to available oxytocin during labor. Lower receptor density would not produce the same level of sensitivity.

2. How can uterine contractions contribute to fetal expulsion without active maternal pushing?

A. They can stimulate voluntary abdominal movements that require conscious maternal effort

B. They can relax the uterus while gravity moves the baby through the birth canal

C. They can suppress oxytocin release while the mother directs each contraction

D. They can become powerful involuntary contractions that move the baby through the birth canal

Answer: (D)

Explanation

As contractions push the baby downward, additional oxytocin can produce powerful involuntary contractions capable of expelling the baby. Voluntary maternal pushing involves conscious effort and is distinct from this involuntary process.

3. How do oxytocin-induced contractions sustain the Ferguson reflex until delivery?

A. They decrease cervical pressure, allowing the uterus to return to its resting state

B. They increase cervical pressure, creating further stretch that reinforces the reflex

C. They interrupt sensory transmission, preventing additional hormonal responses

D. They replace cervical stimulation with voluntary maternal pushing during labor

Answer: (B)

Explanation

Oxytocin-induced contractions push against the cervix and increase cervical pressure, producing additional stretch and further oxytocin release. This reinforcing cycle continues until delivery occurs.

4. What type of feedback mechanism characterizes the Ferguson reflex during labor?

A. A positive feedback loop that strengthens cervical stimulation

B. A voluntary response that depends on maternal abdominal effort

C. A hormonal cycle that operates independently of cervical pressure

D. A negative feedback loop that dampens cervical stimulation

Answer: (A)

Explanation

The Ferguson reflex is positive feedback because cervical or vaginal stretching increases contractions, which further intensify the stimulus. A negative feedback loop would reduce the initial stimulus rather than reinforce it.

5. Which sequence best describes the neural and hormonal pathway of the Ferguson reflex?

A. Cervical relaxation, cortical inhibition, anterior-pituitary signaling, and reduced uterine activity

B. Stretch detection, direct ovarian signaling, adrenal hormone release, and voluntary abdominal contraction

C. Stretch detection, spinal transmission, hypothalamic signaling, posterior-pituitary oxytocin release, and myometrial contraction

D. Oxytocin release, sensory-neuron inhibition, spinal suppression, and decreased myometrial contraction

Answer: (C)

Explanation

The reflex begins with mechanical stretch detection and proceeds through spinal pathways to hypothalamic stimulation, posterior-pituitary oxytocin release, and contraction of the myometrium. The posterior pituitary releases oxytocin; the hypothalamus stimulates it to do so.