Mammary gland gestation, serum progesterone remains at a stably high concentration so signaling through its receptor is continuously activated. As one of the transcribed genes, Wnts secreted from mammary epithelial cells act paracrinely to induce more neighboring cells' branching. When the lactiferous duct tree is almost ready, "leaves" alveoli are differentiated from luminal epithelial cells and added at the end of each branch. In late pregnancy and for the first few days after giving birth, colostrum is secreted. Milk secretion (lactation) begins a few days later due to reduction in circulating progesterone and the presence of another important hormone prolactin, which mediates
Prayer Before Birth Prayer Before Birth Prayer Before Birth is a poem written by the Irish poet Louis MacNeice (1907–1963) at the height of the Second World War. In the poem, Louis MacNeice expresses his fear at what the world's tyranny can do to the innocence of a child and blames the human race "for the sins that in me the world shall commit". The poem also contains many religious themes and overtones through the use of double-imagery; the child could be seen as a metaphor for Christ, making reference to certain themes and events said to have occurred during his ministry on