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
Just What I Needed Just What I Needed "Just What I Needed" is a song by American rock band the Cars, released as their debut single from their self-titled debut album, released in 1978 on Elektra Records. After achieving exposure as a demo, the song became a successful single for The Cars, hitting the top 30 in America. Appearing on numerous compilation albums, it has become one of the band's most popular songs. "Just What I Needed", like many other tracks on "The Cars", originated as a demo tape recorded by the band in 1977. This song first appeared in 1977 on Boston radio