Chapter 17, Section 1 The Body’s Transportation System Monday, March 15, 2010 Pages Monday, March 15, 2010 Pages

ObjectivesObjectives Describe the function of the cardiovascular system. Describe the structure of the heart and explain its function. Describe the origin of the heartbeat and why the heart rate changes during exercise. Trace the path taken by blood through the circulatory system. Describe the function of the cardiovascular system. Describe the structure of the heart and explain its function. Describe the origin of the heartbeat and why the heart rate changes during exercise. Trace the path taken by blood through the circulatory system.

Vocabulary Words Cardiovascular system Heart Atrium Ventricle Valve Cardiovascular system Heart Atrium Ventricle Valve Pacemaker Artery Capillary Vein Aorta Pacemaker Artery Capillary Vein Aorta

The Cardiovascular System Also known as the Circulatory System. Made up of: Heart Blood vessels Blood Carries needed substances to cells and carries waste products away from cells. Also known as the Circulatory System. Made up of: Heart Blood vessels Blood Carries needed substances to cells and carries waste products away from cells.

Movement of Materials Substances that need to get from one part of the body to another are carried by the blood. Wastes are also picked up and expelled through exhalation. Transports cells that attack disease- causing microorganisms. Substances that need to get from one part of the body to another are carried by the blood. Wastes are also picked up and expelled through exhalation. Transports cells that attack disease- causing microorganisms.

Cardiovascular System Blood vessels reach the entire body. RED represents arteries. Arteries are oxygen-rich. BLUE represents veins. Veins are oxygen-poor. Blood vessels reach the entire body. RED represents arteries. Arteries are oxygen-rich. BLUE represents veins. Veins are oxygen-poor.

The Heart Hollow, muscular organ. Pumps blood throughout the body. Size of your fist. Located in the center of your chest. Hollow, muscular organ. Pumps blood throughout the body. Size of your fist. Located in the center of your chest.

The Heart’s Structure The heart has two sides: right and left. Each side is completely separated from each other by a wall of tissue. Each side has two compartments called chambers. There is an upper and lower chamber on each side. –The upper chambers are called atria (atrium - singular). –The lower chambers are called ventricles. The heart has two sides: right and left. Each side is completely separated from each other by a wall of tissue. Each side has two compartments called chambers. There is an upper and lower chamber on each side. –The upper chambers are called atria (atrium - singular). –The lower chambers are called ventricles.

The Heart

The Atrium The atria are separated from the ventricles by valves. –Valves are flaps of tissue that prevents the backflow of blood. The atria receive blood that comes into the heart. The atria are separated from the ventricles by valves. –Valves are flaps of tissue that prevents the backflow of blood. The atria receive blood that comes into the heart.

The Ventricles Located in the lower portion of the heart. Pumps blood out of the heart. Located in the lower portion of the heart. Pumps blood out of the heart.

How The Heart Works Two main phases. –Heart muscles relax and the atria fill with blood. –The atria contract and fill the ventricles and the ventricles contract to pump blood forward. (The sound of your heartbeat is made by this pumping phase.) This process happens in less than a second. Two main phases. –Heart muscles relax and the atria fill with blood. –The atria contract and fill the ventricles and the ventricles contract to pump blood forward. (The sound of your heartbeat is made by this pumping phase.) This process happens in less than a second.

The Valve It is a flap of tissue that prevents the backflow of blood.

Pacemaker A group of cells located in the right atrium. Constantly receives messages about the body’s oxygen needs. Heart rate is adjusted to match needs. A group of cells located in the right atrium. Constantly receives messages about the body’s oxygen needs. Heart rate is adjusted to match needs.

Two Loops Body has three kinds of blood vessels: –ARTERIES -- blood vessels that carry blood away from the heart. –CAPILLARIES -- substances are exchanged between the blood and body cells. –VEINS -- blood vessels that carry blood back to the heart Body has three kinds of blood vessels: –ARTERIES -- blood vessels that carry blood away from the heart. –CAPILLARIES -- substances are exchanged between the blood and body cells. –VEINS -- blood vessels that carry blood back to the heart

Two Loops -- cont’d Blood flows through the body in a figure eight pattern. The heart is at the center where the two loops cross. Blood flows through the body in a figure eight pattern. The heart is at the center where the two loops cross.

Loop One Blood travels from the heart to the lungs and then back to the heart. –Blood from the body flowing into the right atrium is oxygen- poor (low oxygen and high carbon dioxide) –Oxygen-poor blood is dark red. Blood travels from the heart to the lungs and then back to the heart. –Blood from the body flowing into the right atrium is oxygen- poor (low oxygen and high carbon dioxide) –Oxygen-poor blood is dark red.

Loop One -- cont’d Flow of blood: –Right atrium ---> right ventricle ---> arteries towards the lungs ---> capillaries close to the lungs ---> picks up oxygen from the lungs (the blood is now oxygen-rich) ---> carbon dioxide moves from blood into the lungs (and carbon dioxide-poor) ---> blood (bright red now) flows to the left side to be pumped through Loop Two. Flow of blood: –Right atrium ---> right ventricle ---> arteries towards the lungs ---> capillaries close to the lungs ---> picks up oxygen from the lungs (the blood is now oxygen-rich) ---> carbon dioxide moves from blood into the lungs (and carbon dioxide-poor) ---> blood (bright red now) flows to the left side to be pumped through Loop Two.

Loop Two Blood flows to the body and back. –Left atrium fills with oxygen-rich blood coming from the lungs ---> left ventricle --- > aorta (largest artery in the body) ---> branching arteries and tiny capillaries in different parts of the body ---> oxygen moves out of the blood and into the body cells ---> carbon dioxide passes from the body cells into the blood ---> blood flows back to the right atrium through veins. Blood flows to the body and back. –Left atrium fills with oxygen-rich blood coming from the lungs ---> left ventricle --- > aorta (largest artery in the body) ---> branching arteries and tiny capillaries in different parts of the body ---> oxygen moves out of the blood and into the body cells ---> carbon dioxide passes from the body cells into the blood ---> blood flows back to the right atrium through veins.

Homework Workbook 17.1 (3/17) Vocabulary quiz 17.1 (3/17)