UNIT B: Human Body Systems Chapter 8: Human Organization Chapter 9: Digestive System Chapter 10: Circulatory System and Lymphatic System: Section 10.5 Chapter 11: Respiratory System Chapter 12: Nervous System Chapter 13: Urinary System Chapter 14: Reproductive System UNIT B Chapter 10: Circulatory System and Lymphatic System Chapter 10: Circulatory System and Lymphatic System In this chapter, you will learn about the structure and function of the circulatory system and lymphatic system. In 2013, Lance Armstrong confessed to long-term blood doping and the use of banned substances. Blood doping involves artificially boosting the blood’s ability to bring more oxygen to muscles. Aerobic capacity and endurance improve where there are additional red blood cells available to carry oxygen. TO PREVIOUS SLIDE What is the composition of blood, including blood cells? What organs and structures control the flow of blood throughout the body? UNIT B Chapter 10: Circulatory System and Lymphatic System Section 10.5 10.5 Fetal Circulation The fetus has circulatory features not present in adult circulation. These are necessary since the lungs are not functional in the fetus. • Blood passes directly from the right atrium to the left atrium through the foramen ovale between the atria. • Any blood that does not enter the right ventricle and is pumped into the pulmonary trunk is shunted into the aorta by the ductus arteriosus. • Umbilical arteries take fetal blood to the placenta, where the exchange of gases and nutrients between maternal blood and fetal blood takes place. • The umbilical vein then carries the nutrient and O2-rich blood to the fetus. TO PREVIOUS SLIDE UNIT B TO PREVIOUS SLIDE Chapter 10: Circulatory System and Lymphatic System Section 10.5 Figure 10.19 Fetal circulation. The lungs are not functional in the fetus, and the blood passes directly from the right atrium to the left atrium or from the right ventricle to the aorta. The umbilical arteries take fetal blood to the placenta, and the umbilical vein returns fetal blood from the placenta. UNIT B Chapter 10: Circulatory System and Lymphatic System Section 10.5 Structure and Function of the Placenta The placenta is attached to the uterine wall by the allantois and chorionic villi. • Functions only before birth; becomes part of the afterbirth when child is born • Involved in gas, nutrient, and waste exchange between the fetal and maternal circulatory systems • Umbilical cord contains the umbilical arteries and vein, which transport waste to the placenta, and take oxygen and nutrients to the fetal circulatory system TO PREVIOUS SLIDE UNIT B TO PREVIOUS SLIDE Chapter 10: Circulatory System and Lymphatic System Figure 10.20 The Placenta. At the placenta, an exchange of molecules between fetal and maternal blood takes place across the walls of the chorionic villi. Oxygen and nutrient molecules diffuse into the fetal blood, and carbon dioxide and urea diffuse out of the fetal blood. Section 10.5 UNIT B Chapter 10: Circulatory System and Lymphatic System Section 10.5 Check Your Progress 1. Describe the path of blood flow in the fetus, and name the structures unique to fetal circulation. 2. Explain the function of the placenta. TO PREVIOUS SLIDE UNIT B TO PREVIOUS SLIDE Chapter 10: Circulatory System and Lymphatic System Section 10.5