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.
In placental mammals, the umbilical cord is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord is physiologically and genetically part of the fetus and,, normally contains two arteries and one vein, buried within Wharton's jelly. The umbilical vein supplies the fetus with oxygenated, nutrient-rich blood from the placenta. Conversely, the fetal heart pumps deoxygenated, nutrient-depleted blood through the umbilical arteries back to t