One of the most remarkable examples of cell communication is the fight or flight response. body handle extraordinary situations. responses involved in the fight or flight response. place in the movie. 0:16 An environmental signal travels into the brain. a nerve impulse to the hypothalamus (not shown).
Umbilical cord. In placental mammals, the umbilical cord (also called the navel string, birth cord or funiculus umbilicalis) is a conduit between the developing embryo or fetus and the placenta.
As your own blood flows through your uterus, the placenta seeps up nutrients, immune molecules and oxygen molecules circulating through your system. It shuttles these across the amniotic sac â through the umbilical cord that connects placenta to baby â and into your babyâs blood vessels.