Anatomy & Physiology of Lactation Flashcards

Which hormone is primarily responsible for triggering milk ejection during breastfeeding?

Answer: Oxytocin

Oxytocin, released from the posterior pituitary, causes myoepithelial cells surrounding alveoli to contract and eject milk.

What is the primary role of prolactin in lactation?

Answer: Stimulating milk synthesis in alveolar cells

Prolactin, secreted by the anterior pituitary, binds to receptors on alveolar epithelial cells to drive milk synthesis.

During pregnancy, high levels of which hormones suppress full milk production despite rising prolactin?

Answer: Estrogen and progesterone

Placental estrogen and progesterone block prolactin's action on alveolar cells, preventing full lactogenesis until after delivery.

Which cells in the breast surround alveoli and contract in response to oxytocin?

Answer: Myoepithelial cells

Myoepithelial cells are basket-like contractile cells that wrap around alveoli and squeeze milk into the ductal system when stimulated by oxytocin.

Where is prolactin produced?

Answer: Anterior pituitary gland

Prolactin is produced by lactotroph cells in the anterior pituitary gland in response to suckling stimuli.

What effect does dopamine have on prolactin secretion?

Answer: It inhibits prolactin release

Dopamine, also called prolactin-inhibiting factor (PIF), is released by the hypothalamus and tonically suppresses prolactin secretion.

A mother reports that her milk 'lets down' just by hearing her baby cry. Which physiological process explains this?

Answer: Conditioned oxytocin reflex triggered by a sensory cue

Oxytocin release can become conditioned to associated stimuli such as the baby's cry, sight, or smell, triggering the milk ejection reflex without direct nipple stimulation.