The Cardiovascular System

Did You Ever Wonder How Penicillin Works? Penicillin is an antibiotic medicine that works by preventing bacteria from building new cell walls when they divide.

How Does Penicillin Travel through Your Body? Through your Cardiovascular System

The Cardiovascular System has 5 Components 1.Arteries 2.Capillaries 3.Veins 4.Heart(a pump) 5.Blood Blood Vessels ( tubes that carry blood )

Three Types of Blood Vessels There are three types of vessels (tubes) that blood flows through. Arteries – carry blood away from your heart Veins – carry blood in toward your heart Capillaries – tiny vessels carry blood to all your cells

Arteries Arteries are strong, flexible blood vessels that carry blood from the heart to the rest of the body. They expand to accept the blood pumped into them with each beat of the heart, and contract when the heart relaxes. As the arteries become smaller and narrower they turn into capillaries.

Capillaries are the smallest blood vessels …some capillaries are so narrow that only one red blood cell can fit through at a time! Capillaries connect arteries and veins.

Capillaries Arteries Capillaries Veins

Capillary beds carry blood to all the cells in your body artery vein

A Capillary’s Job Nutrients, oxygen (O 2 ) and other substances must leave your blood to get to your body’s cells. Capillary walls are only one cell thick so these substances can pass through to get to your body’s cells. When your cells are done with these substances, waste products such as carbon dioxide (CO 2 ) leave the cells, pass through the capillary walls and enter the blood to be carried away from the cells.

2) Oxygen and nutrients leave the capillary and enter the cells 3) CO 2 and waste products leave the cells and enter the capillary 1) Blood from an artery enters the capillary 4) Blood from the capillary enters a vein What happens in each capillary?

Example: Capillaries surround alveoli in the lungs This is where the blood gives up carbon dioxide and picks up oxygen

Veins Veins carry blood toward the heart. Veins are less elastic (less stretchy) than the arteries. Veins have valves that open to let blood through and close to prevent blood from flowing backward due to the pull of gravity. Varicose veins are caused by weakened valves that allow blood to flow backward and pool inside the vein, causing a bulge.

Amazing Heart Facts The aorta, the largest artery in the body, is almost the diameter of a garden hose. Capillaries are so small that it takes 10 of them to equal the thickness of a human hair. Give a tennis ball a good, hard squeeze. You're using about the same amount of force your heart uses to pump blood out to the body. Even at rest, the muscles of the heart work hard—twice as hard as the leg muscles of a person sprinting.

Your Heart’s Job Your heart is a double pump It is an organ made of cardiac muscle It pumps blood throughout your body –To the lungs to pick up oxygen –To your body to supply your body’s cells with oxygen and other important substances

Blood Flow The following slides will follow the path of blood through the heart. Keep in mind, this is a one-way flow In medical diagrams, the left and right are labeled from the patient’s point of view. What looks like your left on the diagram is really the patient’s right.

As you view the following slides: Color the arrows on the heart diagram indicating the direction of blood flow Use blue to indicate de-oxygenated blood. Use red to indicate oxygenated blood.

De-oxygenated blood enters the right atrium Right Atrium Through the Superior Vena Cava Through the Inferior Vena Cava

De-oxygenated blood passes through the Tricuspid Valve into the Right Ventricle Right Ventricle

The blood is pumped from the right ventricle through the pulmonary artery into the lungs

The blood picks up oxygen in the lungs then heads into the left atrium Left Atrium

The oxygen-rich blood is pumped into the left ventricle then out through the aorta to the body Notice that the path of this blood travels under the pulmonary artery Left Ventricle Aorta

Label your Human Heart Diagram 1.Aortic valve 2.Superior vena cava 3.Right atrium 4.Pulmonary valve 5.Tricuspid valve 6.Inferior vena cava 7.Right ventricle 8. Aorta 9. Pulmonary artery 10. Left atrium 11. Pulmonary vein 12. Bicuspid (Mitral) valve 13. Left ventricle 14. Septum

Key Terms Blood Vessels –Arteries Including the aorta and pulmonary artery –Veins including the Vena cava (superior and inferior) & pulmonary vein –Capillaries Heart Chambers –Right atrium –Left atrium –Right ventricle –Left ventricle Heart Valves –Tricuspid valve –Pulmonary valve –Mitral valve –Aortic valve