How does the mammary gland develop during embryogenesis?
Mammary gland development begins during embryogenesis with the formation of the mammary ridge or milk line, which appears as a thickening of the ectoderm. This ridge extends from the armpit to the groin but usually regresses except at specific locations where the mammary glands will form. The epithelial cells then proliferate and invade the underlying mesenchyme to form the primary mammary bud. This bud undergoes branching morphogenesis to form a tree-like structure of ducts.
