Section 1 The Circulatory System Chapter 46 Objectives • Describe the structure and function of the human heart. • Tracethe flow of blood through the heart and body. • Distinguishbetween arteries, veins, and capillaries in terms of their structure and function. • Distinguishbetween pulmonary circulation and systemic circulation. • Summarizethe functions of the lymphatic system.

Section 1 The Circulatory System Chapter 46 The Heart • The circulatory systemis made up of the cardiovascular system and the lymphatic system. • The cardiovascular system is made up of the the blood, heart, and blood vessels. • The lymphatic system is made up of the lymph, lymph nodes, and the lymph vessels.

Section 1 The Circulatory System Chapter 46 The Heart, continued • The heart is the central organ of the cardiovascular system.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Some of the important parts of the heart are described below. • The septum separates the heart vertically into two sides. • The atrium is an upper chamber of the heart that receives blood that is returning to the heart. • A ventricle is a lower chamber of the heart that pumps blood out of the heart.

Section 1 The Circulatory System Chapter 46 The Heart, continued • The valves are flaps of tissue that control the flow of the fluid. • There are two types of valves: the atrioventricular valves and the semilunar valves. • Theatrioventricular valves prevent blood from flowing backward into the atria. • Thesemilunar valves prevent blood from flowing back into the ventricles when the heart relaxes.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Circulation in the Heart • Path of blood as it circulates through the heart: • Deoxygenated blood enters the right atrium. • The right atrium sends deoxygenated blood into the right ventricle.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Circulation in the Heart, continued • The muscles of the right ventricle contract and force blood into the pulmonary arteries. • The pulmonary artery sends blood to the lungs. In the lungs, carbon dioxide diffuses out of the blood, and oxygen diffuses into the blood.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Circulation in the Heart, continued • The muscular walls of the left ventricle contract and force blood into a large blood vessel. • This blood vessel is called the aorta, and it carries blood from the left ventricle to the rest of the body.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Control of the Heartbeat • The heart contracts its muscle cells in waves. • The first group of heart-muscle cells that are stimulated lie in an area of the heart known as the sinoatrial node. • The sinoatrial (SA) node is a group of specialized heart-muscle cells that lies at the junction of the superior vena cava and the right atrium and regulates the contraction of the heart.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Control of the Heartbeat, continued • The electrical impulse initiated by the SA node eventually reaches another special area of the heart, known as the atrioventricular (AV) node. • The atrioventricular (AV) node is a group of specialized heart-muscle cells that is located between the right atrium and right ventricle and generates electrical impulses that cause the ventricles of the heart to contract.

Section 1 The Circulatory System Chapter 46 Electrical Regulation of the Heart

Section 1 The Circulatory System Chapter 46 Control of the Human Heartbeat Click below to watch the Visual Concept. Visual Concept

Section 1 The Circulatory System Chapter 46 The Heart, continued • Control of the Heartbeat, continued • A heartbeat has two phases. • Phase one is called systole andoccurs when the ventricles contract, closing the AV valves and opening the SL valves to pump blood into the two major vessels that exit the heart.

Section 1 The Circulatory System Chapter 46 The Heart, continued • Control of the Heartbeat, continued • Phase two is called diastole andoccurs when the ventricles relax, allowing the back pressure of the blood to close the SL valves and opening the AV valves. • A series of pressure waves are caused by the contractions of the left ventricle when it forces blood through the arteries. This is called a pulse.

Section 1 The Circulatory System Chapter 46 Blood Vessels • The circulatory system is known as a closed system because the blood is contained within either the heart or the blood vessels at all times. • The blood vessels that are part of the human circulatory system form a vast network to help keep the blood flowing in one direction.

Section 1 The Circulatory System Chapter 46 Anatomy of a Human Heart Click below to watch the Visual Concept. Visual Concept

Section 1 The Circulatory System Chapter 46 Blood Vessels, continued • Arteries and Blood Pressure • The large, muscular vessels that carry blood away from the heart and to the body are called arteries. • Arteries are made up of three layers: an inner endothelial layer, a middle layer of smooth muscle, and an outer layer of connective tissue.

Section 1 The Circulatory System Chapter 46 Blood Vessels, continued • Arteries and Blood Pressure, continued • As the heart moves the blood through the arteries, it produces a great force against the inside walls of a blood vessel. This force is known as blood pressure. • High blood pressure, or hypertension, can place a strain on the walls of the arteries and could cause that artery to burst.

Section 1 The Circulatory System Chapter 46 Blood Vessels, continued • Arteries and Blood Pressure, continued • In order to measure blood pressure, systolic pressure and diastolic pressure must be measured. • Systolic pressure, measured first, is the pressure of the blood when the ventricles contract. • Diastolic pressure, measured second, indicates the steady flow of blood through the artery.

Section 1 The Circulatory System Chapter 46 Blood Vessels, continued • Capillaries and Veins • From the artery, a series of smaller vessels called arterioles carry the blood to capillaries. • The capillaries are a vast network of tiny vessels that allow an exchange between the blood and the cells to occur.

Section 1 The Circulatory System Chapter 46 Blood Vessels, continued • Capillaries and Veins, continued • After cells interact with the blood, the blood goes back to the heart. To do this, capillaries merge to form venules. • These venules are connected to a vein. A vein is a bundle of vascular tissue that transports fluids and nutrients back to the heart. • Veins are made up of three layers: endothelium, smooth muscle, and connective tissue.

Section 1 The Circulatory System Chapter 46 Blood Vessels

Section 1 The Circulatory System Chapter 46 Types of Blood Vessels Click below to watch the Visual Concept. Visual Concept

Section 1 The Circulatory System Chapter 46 Patterns of Circulation • The heart and blood vessels work together to form a continuous, closed system of circulation. • This system contains two subsystems: the pulmonary circulation and the systemic circulation.

Section 1 The Circulatory System Chapter 46 Circulatory Pathway in the Human Body

Section 1 The Circulatory System Chapter 46 Anatomy of the Human Cardiovascular System Click below to watch the Visual Concept. Visual Concept

Section 1 The Circulatory System Chapter 46 Patterns of Circulation, continued • Pulmonary Circulation • Pulmonary circulation is the circulation of the blood as it travels between the heart and lungs. • Pulmonary circulation brings the deoxygenated blood that comes into the heart to the lungs, and returns oxygenated blood back to the heart for distribution to the body.

Section 1 The Circulatory System Chapter 46 Patterns of Circulation, continued • Systemic Circulation • Systemic circulation is the circulation of the blood between the heart and all other body tissues. • Systemic circulation has several subsystems, including coronary circulation, hepatic portal circulation, and renal circulation.

Section 1 The Circulatory System Chapter 46 Patterns of Circulation, continued • Systemic Circulation, continued • Coronary circulation is the systemic circulation that supplies blood to the heart itself. • If blood flow in the coronary arteries (arteries that supply blood to the heart) is reduced or cut off, muscle cells will die.

Section 1 The Circulatory System Chapter 46 Patterns of Circulation, continued • Systemic Circulation, continued • Hepatic portal circulation is the systemic circulation that supplies blood between the liver and the small intestines. • Renal circulation is the systemic circulation that supplies blood to the kidneys.

Section 1 The Circulatory System Chapter 46 Circulatory Loops in the Human Body

Section 1 The Circulatory System Chapter 46 Lymphatic System • The circulatory system also includes the lymphatic system. • The lymphatic system returns fluids that have collected in the tissues to the bloodstream. • Excess fluid in the tissues, called lymph, moves into the tiny vessels of the lymphatic system by diffusion.

Section 1 The Circulatory System Chapter 46 Lymphatic System, continued • Lymph vessels are similar to blood vessels but are also different in many ways. • Lymph is filtered through small organs known as lymph nodes to trap tissue debris and other foreign particles. • Lymph nodes also store lymphocytes, white blood cells that are specialized to fight disease.

Section 1 The Circulatory System Chapter 46 Lymphatic System

Section 2 Blood Chapter 46 Objectives • Listthe components of blood. • Distinguishbetween red blood cells, white blood cells, and platelets in terms of their structure and function. • Summarizethe process of blood clotting. • Explainwhat determines the compatibility of blood types for transfusion.

Section 2 Blood Chapter 46 Composition of Blood • Blood is composed of a liquid medium—plasma—and blood solids–red and white blood cells and platelets. • Plasma • Plasma is a sticky, straw-colored fluid that is about 90 percent water and includes metabolites, nutrients, wastes, salts, and proteins. • Plasma provides cells with nourishment and carries various proteins.

Section 2 Blood Chapter 46 Composition of Blood, continued • Red Blood Cells • A red blood cell is a disc-shaped cell that has no nucleus and transports oxygen to cells in all parts of the body. • Immature red blood cells synthesize large amounts of an iron-containing protein called hemoglobin. Hemoglobin is the molecule that transports oxygen.

Section 2 Blood Chapter 46 Composition of Blood, continued • White Blood Cells • White blood cells are cells in the blood that destroy bacteria, viruses, and toxic proteins and helps the body develop immunities. • In addition to different functions, white blood cells also have a different structure and life span than red blood cells.

Section 2 Blood Chapter 46 Composition of Blood, continued • White Blood Cells, continued • There are several types of white blood cells, including phagocytes and antibodies. • Phagocytes are cells that engulf and digest foreign matter or microorganisms. • Antibodies are proteins that react to a specific type of invader or inactivate or destroy toxins.

Section 2 Blood Chapter 46 Composition of Blood

Section 2 Blood Chapter 46 Blood Types • Red blood cells have surface proteins that are used to classify a person’s blood. The type of surface protein determines a person’s blood type. • The surface proteins on a red blood cell or on an invading pathogen are called antigens. • The most important human antigens are A, B, and Rh. They form two systems of blood typing: the A-B-O system and the Rh system.

Section 2 Blood Chapter 46 Blood Types, continued • A-B-O System • The A-B-O system is a means of classifying blood by the antigens located on the surface of the red blood cells and the antibodies circulating in the plasma. • If blood of a different type is introduced into the body it will be treated as a foreign invader and the antigen-antibody reaction will be produced, with some exceptions.

Section 2 Blood Chapter 46 Blood Types, continued • Rh System • The Rh system is based on the presence or absence of the Rh antigen. • A person with Rh antigens is Rh positive; a person without Rh antigens is Rh negative. • Similar complications to those of the ABO system can occur if blood containing the wrong Rh antigens is transfused into a person.

Section 2 Blood Chapter 46 Blood Types

Section 3 The Respiratory System Chapter 46 Objectives • Differentiateexternal respiration from internal respiration. • Tracethe path of air from the atmosphere to the bloodstream. • Describehow gases are exchanged in the lungs and transported in the bloodstream. • Summarizethe skeletal and muscular changes that occur during breathing. • Describehow the rate of breathing is controlled.

Section 3 The Respiratory System Chapter 46 Respiration • The function of the respiratory system is to exchange gases with the cardiovascular system. • The respiratory system involves both external respiration and internal respiration. • External respiration is the exchange of gases between the atmosphere and the blood. • Internal respiration is the exchange of gases between the blood and the cells of the body.

Section 3 The Respiratory System Chapter 46 The Human Respiratory System

Section 3 The Respiratory System Chapter 46 Parts of the Human Respiratory System Click below to watch the Visual Concept. Visual Concept

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