ANATOMY

Detailed explanation-1: -However, as the abdomen enlarges, the kidneys are drawn apart and ascend to their final position in the lumbar region between weeks six to nine.

Detailed explanation-2: -Urine formation begins towards the end of the first trimester (weeks 11 to 12) and continues throughout fetal life. The kidneys develop in the pelvis and ascend during development to their adult anatomical location at T12-L3. This normally happens by the ninth week.

Detailed explanation-3: -The metanephric kidney ascends from the pelvic to the thoracolumbar region. This process is thought to occur as the result of a decrease in body curvature and body growth of the lumbar and sacral regions.

Detailed explanation-4: -Human kidney development begins as early as the third week of embryonic development, with formation of the pronephros, followed by the mesonephros at 4 weeks and the metanephros at 5 weeks gestation. The first glomeruli appear at nine weeks in humans, and nephrogenesis is complete by 36 weeks gestation.