Cardiovascular and Respiratory Systems

1. Cardiovascular and Respiratory Systems Lesson 1: The Cardiovascular System Lesson 2: Caring for the Cardiovascular System Lesson 3: The Respiratory System Lesson 4: Caring for the Respiratory System

2. The Cardiovascular System Lesson 1

3. Functions of the Cardiovascular System A function of the cardiovascular system is to circulate blood, and thus maintain an environment in which all the cells in your body are nourished. Your heart pumps blood throughout your body. The blood carries oxygen and nutrients to your cells, and it takes carbon dioxide and waste products away from cells.

4. Structure of the Cardiovascular System The cardiovascular system consists of the heart, blood, and blood vessels.

5. (Structure Continued) Your heart is one of the most important organs in your body. It is the pump that makes the cardiovascular system work; it never rests. The heart has four chambers. Blood is pumped from the heart to the lungs, where it releases carbon dioxide and picks up air. The oxygenated blood returns to the heart and is pumped to the rest of the body.

6. (Structure Continued) Blood delivers oxygen, hormones, and nutrients to the cells and carries away wastes that the cells produce. About 55% of total blood volume consists of plasma, the fluid in which other parts of the blood are suspended. Platelets are cells that prevent the body’s loss of blood. Red blood cells transport oxygen to the cells and tissues of the body. White blood cells protect the body against infection and fight infection when it occurs.

7. (Structure Continued) Blood is transported in blood vessels. There are three main types of blood vessels. (p. 418) Arteries are blood vessels that carry blood away from the heart. The very smallest arteries are called arterioles. Capillaries are very small blood vessels that carry blood between arterioles and venules. Capillaries have ultra-thin walls. Veins are blood vessels that return blood to the heart. The very smallest veins are called venules.

8. The Lymphatic System The lymphatic system helps fight infection and plays an important role in the body’s immunity to disease.

9. (Lymphatic Continued) Lymph is a clear fluid that fills the spaces around the body cells. It is transported by the lymphatic system to the heart and eventually returns to the blood. The lymphatic system consists of a network of vessels and tissues that are involved in the movement of filtering of lymph. (p. 422)

10. Caring for the Cardiovascular System Lesson 2

11. Cardiovascular System Problems • Certain heart problems are congenital, or present at birth. • Cardiovascular disease is a group of diseases of the cardiovascular system. It includes hypertension, heart disease, and stroke. • Heart murmurs are abnormal sounds made as blood flows through the heart. Heart murmurs may indicate serious problems with the heart.

12. (Problems Continued) • Varicose veins form if valves in the veins do not close tightly enough to prevent backflow of blood. Physical activity helps prevent varicose veins. • Anemia is a condition in which the ability of the blood to carry oxygen is reduced. • Leukemia is a form of cancer in which any one of the different types of white blood cells is produced excessively and abnormally. • Hemophilia is an inherited disorder in which the blood does not clot properly.

13. Lymphatic System Problems • Immune deficiencies occur when the immune system can no longer protect against infection. Some immune deficiencies are congenital; others are caused by HIV. • Hodgkin’s disease is a type of cancer that affects the lymph tissue. • Tonsillitis, or infected tonsils, is another possible problem with the lymphatic system. Tonsils are part of the immune system and help reduce the number of pathogens entering the body.

14. The Respiratory System Lesson 3

15. Functions of the Respiratory System The main function of the respiratory system is respiration- the exchange of gases between the body and the environment.

16. (Functions Continued) Respiration has two parts: External respiration is the exchange of oxygen and carbon dioxide that takes place between air and the blood in the lungs. Internal respiration is the exchange of gases between the blood and the body cells. The continual exchange of gases in both the external and internal respiration is essential for survival.

17. Structure of the Respiratory System The upper respiratory system includes the nose and throat; the lower respiratory system consists of the lungs, larynx, trachea, and bronchi.

18. (Structure Continued) The lungs are the principle organs of the respiratory system. (p. 429) The lungs are in the chest, protected by the ribs. The diaphragm is the muscle that separates the chest from the abdominal cavity. Air moves into the lungs through the trachea, or windpipe. The trachea braches out into bronchi, the main airways that reach into each lung.

19. (Structure Continued) • The breathing process is made possible when your body creates a pressure difference between the lungs and the outside of the body. • Air enters the body through the nose and mouth. It passes through the pharynx, or throat, and then into the trachea and then the bronchi • The larynx, or voice box, connects the throat and the trachea. • The epiglottis is a flap of cartilage above the larynx. It folds down to keep food or drink from entering the respiratory system.

20. Caring for theRespiratory System Lesson 4

21. Health Behaviors and the Respiratory System The most important decision you can make for respiratory health is not to smoke. Regular physical activity also promotes the health of the respiratory system. Washing your hands regularly helps prevent infections of the respiratory disorders. Limiting your exposure to pollutants, including environmental tobacco smoke, can reduce your risk of developing respiratory disorders.

22. Respiratory System Problems • Bronchitis is an inflammation of the bronchi caused by infection or by exposure to irritants, such as tobacco smoke and air pollution. • Pneumonia is an inflammation of the lining of the lungs and chest cavity. • Asthma is an inflammatory condition in which the trachea and bronchi become narrowed, causing difficulty in breathing.

23. (Problems Continued) • Sinusitis is an inflammation of the tissues that line the sinuses- air-filled cavities above the nasal passages and throat. • Tuberculosis is a contagious bacterial infection that usually affects the lungs. • Emphysema is a disease that progressively destroys the walls of the alveoli. The alveoli are the microscopic air sacs within the lungs.