Circulatory and Respiratory Systems

1 Name Class Date Chapter 33 Workbook A Copyright by Pearson Education, Inc., or its affi liates. All Rights Circulatory and Respiratory Systems Structure and FunctionQ: How do the structures of the Circulatory and Respiratory Systems allow for their close functional relationship?WHAT I How are oxygen and carbon dioxide exchanged between humans and the environment? What structures transport substances throughout the human body? What are the roles of blood and the lymphatic system in the body?WHAT I KNOWSAMPLE ANSWER: The heart pumps blood, and blood vessels carry blood throughout the ANSWER: Pulmonary circulation pumps blood from the heart to the lungs and back.

2 Systemic circulation pumps blood from the heart to the cells of the body. Three types of blood vessels are arteries, capillaries, and ANSWER: Blood carriesoxygen and nutrients throughout the body. The lymphatic system works with the Circulatory ANSWER: The components of blood transport oxygen, guard against infection, make blood clotting possible, and make up about 55 percent of total blood volume. The lymphatic system screens lymph for microorganisms and is involved in the absorption of nutrients and in ANSWER: Breathing brings air into the lungs and exhales ANSWER: The human Respiratory system picks up oxygen from air during inhalation.

3 Carbon dioxide is released during exhalation. Oxygen and carbon dioxide are exchanged across the walls of alveoli and 11/5/09 12:48:20 PMLesson Workbook A Copyright by Pearson Education, Inc., or its affi liates. All Rights Class Date The Circulatory SystemLesson Objectives Identify the functions of the human Circulatory system . Describe the structure of the heart and explain how it pumps blood through the body. Name three types of blood vessels in the Circulatory SummaryFunctions of the Circulatory system The Circulatory system transports oxygen, nutrients, and other substances throughout the body, and removes wastes from Heart The muscle layer of the heart is the myocardium.

4 Its powerful contractions pump blood through the Circulatory system . The human heart has four chambers. A wall called the septum separates the right side of the heart from the left side. On each side of the septum are an upper and lower upper chamber, or atrium (plural: atria), receives blood from the body; each lower chamber, or ventricle, pumps blood out of the heart. Flaps of connective tissue called valves are located between the atria and the ventricles and between the ventricles and blood vessels leaving the heart. The valves open and close to keep blood moving in one direction. The heart pumps blood through two pathways: Pulmonary circulation pumps blood from the heart to the lungs and back to the heart again.

5 Blood picks up oxygen and releases carbon dioxide in the circulation pumps blood from the heart to the rest of the body. Cells absorb much of the oxygen and load the blood with carbon heart muscle beats in an orderly and coordinated way. A small group of cardiac muscle fibers, the sinoatrial node (SA node), is also called the pacemaker. When the pacemaker fires, an electrical impulse causes the atria to contract. Another group of muscle fibers, the atrioventricular node (AV node), causes the ventricles to contract. The nervous system influences the SA node, increasing or decreasing heart rate to meet the body s Vessels Blood flows through the Circulatory system in blood vessels:Arteries are large vessels that carry blood away from the heart to the tissues of the body.

6 Except for the pulmonary arteries, all arteries carry oxygen-rich are the smallest vessels. Their thin walls allow oxygen and nutrients to pass from blood into tissues and wastes to move from tissues into return blood to the heart. Many have valves that prevent contractions of the heart produce a wave of fluid pressure in the arteries, known as blood pressure. Without that pressure, blood would stop flowing through the body. The body regulates blood pressure through actions of the brain and the 21/5/09 12:48:24 PMLesson Workbook A Copyright by Pearson Education, Inc., or its affi liates. All Rights Class Date Functions of the Circulatory system 1.

7 Why do animals with millions of cells need a Circulatory system while animals with few cells can do without one? 2. Marie lives in a large city. She is disabled and cannot leave her home. Everything she needs must be delivered to her, and all her garbage must be hauled away. Compare how the streets and highways of the city supply Marie s needs with how the Circulatory system supplies the needs of individual cells of the human Heart 3. Complete the PathwaySide of Heart PumpingDestination After Leaving HeartBlood ChangePulmonarySystemicIf all cells are in direct contact with the environment, diffusion and active transport can provide nutrients and oxygen and remove wastes.

8 Large, multicellular organisms have cells that are not in direct contact with the environment. A Circulatory system is required to serve those s food, medicines, and other supplies are brought to her door by delivery people who travel along streets and highways. Garbage collectors use those same streets and highways to collect and haul away her trash. The same thing happens in the body. Delivery people (blood cells) travel along streets and highways (arteries and veins). They deliver supplies like oxygen and nutrients. They also collect waste prod-ucts like carbon dioxide and haul them poor to oxygen richLeftBodyOxygen rich to oxygen 31/5/09 12:48:26 PMLesson Workbook A Copyright by Pearson Education, Inc.

9 , or its affi liates. All Rights Class Date 4. Label the diagram at the points indicated to show the structures of the human Circulatory system . Add arrows to show the direction of blood ofhead and armsartery ofleft lungCapillaries ofabdominal organsand legsInferiorPulmonaryCapillaries vena 5. Complete the flowchart to show the actions that keep the heart beating in an orderly SA node firesElectrical impulse spreads through the atria and the atria contractAV node produces impulses that spread through the ventriclesImpulse from the SA node is picked up by the AV nodeVentricles contract and pump blood out of the heartImpulse is delayed while the atria contract and pump blood to the 41/5/09 12:48:29 PMLesson Workbook A Copyright by Pearson Education, Inc.

10 , or its affi liates. All Rights Class Date Blood Vessels 6. As blood flows through the body, it passes through three types of blood vessels. Complete the table by naming each type and describing its structure and function. Blood vessels StructureFunction 7. Complete the feedback diagram to show how the nervous system regulates blood pressure relax smooth muscles in blood vessel cause smooth muscles in vessel walls to pressure rises 8. The left side of the heart is larger and more muscular than the right side.