Technical Abstract: The chapter provides a powerpoint presentation describing the physiological basis for the onset and maintenance of lactation. A class activity is included which requires comprehension and application of concepts to clinical management. The relative importance of hormone levels (progesterone, estrogen, prolactin, insulin and cortisol) and breast stimulation are contrasted for lactogenesis stages I, II and III. Physiological bases for failed lactogenesis are reviewed including hypoplastic breast tissue, retained placenta, and excessive blood loss during delivery). Physiologic mechanisms triggering mammary resorption are reviewed including elevated intrammary pressure, inadequate tactile stimulation, and selected drugs. Strategies for increasing milk production are reviewed in relation to their impact on underlying physiology. The adult learning activity incorporates discussion of the impact of common management practices on underlying factors that impact lactogenesis and/or volume maintenance.