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.
A special cord called the umbilical cord links the placenta to the fetus. The mother's blood flows through a thin layer of cells in the wall of the uterus, giving the fetus food and oxygen while removing any wastes like carbon dioxide.he baby growing inside of the mother's uterus (the womb) is called a fetus. The growing fetus is fully dependent on a special organ called the placenta for nourishment. One side of the placenta is attached to the uterus, and the other side is attached to a liquid-filled sac that holds the fetus.