CLE Anatomy & Physiology of Lactation 4

Question 1

Which nerve pathway carries sensory signals from nipple stimulation to the hypothalamus to trigger oxytocin release?

Accepted Answer

Thoracic spinal nerves T3–T5 via the spinothalamic tract

Answer

Sensory signals from nipple mechanoreceptors travel via intercostal branches of thoracic spinal nerves T3–T5 to the hypothalamus, stimulating oxytocin release.

Question 2

Stress and pain can inhibit the milk ejection reflex primarily by elevating which hormone?

Accepted Answer

Epinephrine (adrenaline)

Answer

Elevated epinephrine from stress causes vasoconstriction of mammary blood vessels, reducing oxytocin delivery to myoepithelial cells and inhibiting let-down.

Question 3

A mother notices milk dripping from the opposite breast while nursing on one side. Which physiological event causes this?

Accepted Answer

Bilateral systemic oxytocin release triggering both breasts simultaneously

Answer

Oxytocin released into the bloodstream acts systemically, triggering myoepithelial contraction in both breasts simultaneously, causing milk to leak from the non-nursing breast.

Question 4

What is the primary mechanism by which frequent nursing maintains high prolactin levels?

Accepted Answer

Nipple stimulation suppresses hypothalamic dopamine, allowing prolactin to rise

Answer

Suckling stimulates afferent nerve signals that suppress hypothalamic dopamine (PIF) release, removing inhibition and allowing prolactin surges with each feeding.

Question 5

At what time of day are prolactin levels typically highest, and what is the clinical implication?

Accepted Answer

Early morning; nighttime and early morning feeds are most effective for maintaining supply

Answer

Prolactin follows a circadian rhythm with peaks during sleep and early morning, making nighttime and early morning nursing sessions particularly effective for sustaining milk supply.

(CLE) Certified Lactation Educator Practice Test

(CLE) Certified Lactation Educator Practice Test

CLE Anatomy & Physiology of Lactation 4