How are nutrients carried from mother to baby in mammals?

Nutrients are carried from mother to fetus through the placenta, a specialized organ that forms during pregnancy. Here's an explanation of how nutrients are transported:

1. Maternal Blood Supply: The placenta is connected to the mother's circulatory system through the uterine wall. The mother's blood vessels carry oxygen, nutrients, hormones, and waste products to the placenta.

2. Placental Exchange: The placenta consists of two layers: the maternal layer, which is derived from the uterine lining, and the fetal layer, which is formed from the developing embryo. The two layers are separated by a thin membrane called the placental barrier.

3. Diffusion and Active Transport: Nutrients, oxygen, and waste products are exchanged between the maternal and fetal circulatory systems through the placental barrier. Oxygen and nutrients from the mother's blood diffuse across the placental barrier and into the fetal blood vessels. This process is facilitated by the concentration gradient and does not require energy input.

4. Maternal-Fetal Blood Separation: The maternal and fetal circulatory systems do not mix. The fetal blood vessels carry the oxygen and nutrients to the developing fetus, while the waste products produced by the fetus are transported back to the mother's circulation through the placental barrier.

5. Umbilical Cord: The oxygenated and nutrient-rich blood from the placenta passes to the fetus through the umbilical cord. The umbilical cord contains three blood vessels: two arteries carrying deoxygenated blood from the fetus to the placenta and one vein bringing oxygenated blood and nutrients back to the fetus.

By facilitating the exchange of oxygen, nutrients, and waste products between the maternal and fetal circulatory systems, the placenta plays a crucial role in providing the developing fetus with the necessary nourishment for growth and development throughout gestation.