Q.Explain the role of oxytocin in both parturition and lactation.

[!TLDR]

Oxytocin drives the uterine contractions of parturition (via a positive-feedback foetal ejection reflex) and, separately, the milk-ejection (let-down) reflex of lactation. …

Oxytocin, secreted by the posterior pituitary, plays central but distinct roles in these two processes. In parturition, signals from the full-term foetus and cervical stretch trigger oxytocin release, which strengthens uterine contractions; the resulting increase in cervical stretch triggers still more oxytocin, an escalating positive-feedback loop (the foetal ejection reflex) that intensifies contractions until delivery. In lactation, an entirely separate reflex is involved: sensory signals from the infant's suckling at the nipple trigger oxytocin release from the same posterior pituitary, but here oxytocin acts on myoepithelial cells surrounding the mammary alveoli, causing them to contract and eject stored milk -- the let-down reflex. In both cases the underlying logic is the same (a mechanical/sensory stimulus triggeri …

Treat the two roles separately: identify the trigger, the target tissue and the outcome for parturition, then do the same for lac …

Assuming oxytocin's role is identical in both processes because it is 'the same hormone' -- the trigger (cervical stretch vs suckling) and the target tissue (uterine s …