End Show Slide 1 of 51 Copyright Pearson Prentice Hall 37–1 The Circulatory System

End Show 37–1 The Circulatory System Slide 2 of 51 Copyright Pearson Prentice Hall Functions of the Circulatory System Transport materials – O 2,CO 2,food,waste Fight Diseases – WBC, antibodies Clot – plateletes, plasma proteins Maintain body temperature – water Chemical balance – pH, osmosis

End Show 37–1 The Circulatory System Slide 3 of 51 Copyright Pearson Prentice Hall Functions of the Circulatory System The human circulatory system consists of: the heart blood vessels blood

End Show 37–1 The Circulatory System Slide 4 of 51 Copyright Pearson Prentice Hall The Heart The heart is enclosed in a sac called the pericardium. The heart is composed of cardiac muscle. 4 chambers – 2 upper & 2 lower Atria (upper) – receive blood from body Ventricles (lower) – pump blood to body Valves – prevent backflow of blood

End Show 37–1 The Circulatory System Slide 5 of 51 Copyright Pearson Prentice Hall The Heart Blood Flow thru the Heart

End Show 37–1 The Circulatory System Slide 6 of 51 Copyright Pearson Prentice Hall Blood Vessels As blood flows through the circulatory system, it moves through three types of blood vessels: arteries capillaries veins

End Show 37–1 The Circulatory System Slide 7 of 51 Copyright Pearson Prentice Hall Blood Vessels Arteries Carry blood away from the heart. All are Red, except for the pulmonary arteries. Arteries have thick walls.

End Show 37–1 The Circulatory System Slide 8 of 51 Copyright Pearson Prentice Hall Blood Vessels

End Show 37–1 The Circulatory System Slide 9 of 51 Copyright Pearson Prentice Hall Blood Vessels Veins Carry blood back to the heart. All are Blue, except for the pulmonary veins. Large veins contain valves that keep blood from moving backwards.

End Show 37–1 The Circulatory System Slide 10 of 51 Copyright Pearson Prentice Hall Blood Vessels

End Show 37–1 The Circulatory System Slide 11 of 51 Copyright Pearson Prentice Hall Blood Vessels Many veins are located near and between skeletal muscles. Valve open Valve closed Valves closed

End Show 37–1 The Circulatory System Slide 12 of 51 Copyright Pearson Prentice Hall Blood Vessels Capillaries The smallest blood vessels. One cell thick and one cell wide. Exchanges of nutrients and gases occurs here between tissues and the blood.

End Show 37–1 The Circulatory System Slide 13 of 51 Copyright Pearson Prentice Hall Blood Vessels

End Show 37–1 The Circulatory System Slide 14 of 51 Copyright Pearson Prentice Hall The Heart Circulation Through the Body The heart functions as two separate pumps. Pulmonary Circulation - circulates blood between the heart and the lungs. Systemic Circulation - circulates blood between the heart and the rest of the body.

End Show 37–1 The Circulatory System Slide 15 of 51 Copyright Pearson Prentice Hall The Heart Circulation of Blood through the Body Capillaries of head and arms Superior vena cava Aorta Pulmonary vein Capillaries of right lungs Inferior vena cava Capillaries of abdominal organs and legs Capillaries of left lung Pulmonary artery

End Show 37–1 The Circulatory System Slide 16 of 51 Copyright Pearson Prentice Hall The Heart Sinoatrial (SA) node Conducting fibers Heartbeat – Pacemaker initiates a signal across the atria.

End Show 37–1 The Circulatory System Slide 17 of 51 Copyright Pearson Prentice Hall The Heart Conducting fibers Atrioventricular (AV) node The atrioventricular (AV) node carries the signal to the network of fibers in the ventricles.

End Show 37–1 The Circulatory System Slide 18 of 51 Copyright Pearson Prentice Hall Blood Pressure When the heart contracts a wave of pressure forms in the arteries. Pacemaker – initiates heart contractions Systolic Pressure – ventricles contract Diastolic Pressure – ventricles relax 120/80 is average

End Show Slide 19 of 51 Copyright Pearson Prentice Hall 37–1 The layer of muscle in the heart that pumps blood through the circulatory system is called the a.myocardium. b.atrium. c.ventricle. d.vena cava.

End Show Slide 20 of 51 Copyright Pearson Prentice Hall 37–1 Oxygen-poor blood from the body enters the heart through the a.left atrium. b.left ventricle. c.right atrium. d.right ventricle.

End Show Slide 21 of 51 Copyright Pearson Prentice Hall 37–1 Atherosclerosis is a condition in which a.blood cells die from a lack of oxygen. b.plaque builds up along the walls of the arteries. c.blood pressure is too high. d.the heart stops pumping blood.

End Show Slide 22 of 51 Copyright Pearson Prentice Hall 37–1 The inner wall of all blood vessels is lined with a.endothelium. b.connective tissue. c.smooth muscle. d.myocardium.

End Show Slide 23 of 51 Copyright Pearson Prentice Hall 37–1 The vein that brings oxygen-poor blood from the upper part of the body to the right atrium is the a.pulmonary vein b.inferior vena cava. c.aorta d.superior vena cava.