Chapter 12

1. Chapter 12 Clearing the AirRespiratory, Cardiovascular, and Urinary Systems 0

2. 1 Effects of Smoke on the Respiratory System ETS – Environmental Tobacco Smoke or “secondhand smoke” is inhaled by passive smokers - people who are in the same environment as active smokers Carbon monoxide  most abundant chemical in ETS ETS has a high concentration of particulates (tar) ETS damages lungs, but chemicals can also pass into bloodstream

3. 1 Effects of Smoke on the Respiratory System On average, a resting human: Breathes once every 12 seconds Takes a breath with a volume of about 500 milliliters Sends about 1 liter of air per minute into the lungs

4. 1 Effects of Smoke on the Respiratory System – Diaphragm The respiratory system is separated from the digestive organs by the diaphragm. When the diaphragm contracts, it flattens. Simultaneously, the rib cage lifts up and out. Volume of chest cavity increases, pressure lowers and air rushes in. When diaphragm relaxes, chest cavity loses volume, pressure increases, and air leaves.

5. 1 Effects of Smoke on the Respiratory System – Diaphragm • Inhalation brings air into the lungs and exhalation brings air out of the lungs.

6. 1 Effects of Smoke on the Respiratory System – Lungs Healthy lungs are spongy, pink sacs that fill the chest cavity. Lungs are attached to the chest wall by a double-layered membrane. Air enters the lungs through bronchi. Bronchi branch into bronchioles. Bronchioles finally end at alveoli—small, vascularized sacs. Alveoli are the functional unit of the lung and where gas exchange occurs.

7. 1 Effects of Smoke on the Respiratory System – Lungs On average, lungs contain about 300 million alveoli, and these contain the respiratory surface through which the body acquires oxygen and eliminates CO2 waste. The total area of the respiratory surface in a pair of lungs is about the same area as a tennis court.

8. 1 Effects of Smoke on the Respiratory System – Lungs Each alveolus is surrounded by a net of capillaries – tiny, thin-walled blood vessels that connect the gases exchanged with the body.

9. 1 Effects of Smoke on the Respiratory System – Gas Exchange Gas exchange is the primary function of the lungs: O2 from the environment is exchanged for CO2 from the body. Gas exchange occurs by simple diffusion between the alveoli and the capillaries.

10. 1 Effects of Smoke on the Respiratory System – The Role of Hemoglobin in Gas Exchange CO2 easily diffuses from blood to air; O2 requires help to enter the blood. Hemoglobin – respiratory pigment Hemoglobin produces color when it binds with oxygen. A single hemoglobin is made up of 4 different protein chains, each with an iron atom. Iron binds to the oxygen and carries it in the blood. A red blood cell contains about 250 million hemoglobin molecules; it can carry 1 billion oxygen molecules.

11. 1 Effects of Smoke on the Respiratory System – The Role of Hemoglobin in Gas Exchange Hemoglobin is efficient at binding O2, but even more effective at binding carbon monoxide. Even small amounts of carbon monoxide can tie up a lot of hemoglobin. Carbon monoxide causes oxygen shortages in tissues. Carbon monoxide is especially damaging to fetuses and embryos. Lower than average birth weights associated with smoking mothers are due to oxygen deprivation.

12. 1 Effects of Smoke on the Respiratory System – Smoke Particles and Lung Function Normal function of the lungs: Cough is first response to lung irritants Small particles don’t trigger cough; they become trapped in mucus lining the respiratory tract Cilia move trapped particles to nose and mouth Mucus is coughed out or swallowed The majority of the damage to lungs is caused by particulates in smoke, which damage the surfaces of the lungs. Children and infants are particularly vulnerable

13. 1 Effects of Smoke on the Respiratory System – Smoke Particles and Lung Function Particles can interfere with the lung’s defense systems Particulates increase mucus production, but damage cilia leading to bronchitis Asthma is an allergic reaction where bronchioles constrict and mucus production increases. Particulates are known to exacerbate asthma. The EPA estimates that environmental tobacco smoke, or ETS, will cause 26,000 additional cases of asthma.

14. 1 Effects of Smoke on the Respiratory System – Emphysema Emphysema is caused by scar tissue formation due to chronic bronchitis and asthma. Alveoli can become damaged and merge into fewer and larger sacs. This drastically reduces surface area for gas exchange. The damage is permanent; lung tissue is not regenerated.

15. 1 Effects of Smoke on the Respiratory System – Lung Cancer Many of the particulates in cigarette smoke contain chemicals known to be carcinogens Particulates can stay on lung surfaces for long periods of time Risk of mutation remains long after cigarette has been smoked leading to cancer

16. Animation: Gas Exchange in the Lung Click “Go to Animation” / Click “Play” BioFlix: Gas Exchange

17. 2 Spreading the Effects of Smoke: The Cardiovascular System The cardiovascular system consists of three main components: Circulating fluid (blood) Pump (heart) Vascular system (blood vessels and capillaries)

18. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood The average adult human has 5 liters (11 pints) of blood, which consists of solid (cellular) and liquid components. Liquid portion  plasma Cellular portion  red blood cells, white blood cells, platelets

19. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Cellular components of blood are produced by stem cells in the bone marrow.

20. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Red blood cells Carry oxygen; shape provides large surface area to volume ratio Lacks a nucleus or mitochondria which increases the carrying capacity of the RBC White blood cells Several varieties Essential components of immune system Removes toxins, wastes, and damaged cells Platelets Uses proteins like fibrin to perform blood clotting Formation of blood clots help prevent blood loss

21. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Platelets Substances in tobacco smoke increases the stickiness of platelets and formation of fibrinogen. This leads to an increase in clot formation even when clots are not needed. A clot that forms that shouldn’t is called a thrombus, and when this clot moves from its original location it is called an embolism.

22. 2 Spreading the Effects of Smoke: The Cardiovascular System – Heart The heart consists of four chambers that make up two pumps.

23. 2 Spreading the Effects of Smoke: The Cardiovascular System – Heart The heart has several control mechanisms. The cardiac cycle involves the SA node and is the complete sequence of filling the heart with blood and pumping it out of the heart. The sino-atrial node (SA node) is the pacemaker and stimulates the heart to beat. Contraction of the heart is called systole and relaxation of the heart is called diastole. When the muscles of the ventricle contract, AV valves prevent backflow into the atria. The semilunar valves prevent backflow into the ventricles when the ventricles relax.

24. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Vessels The vascular system includes arteries, capillaries, and veins.

25. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Vessels Arteries – carry blood away from heart, have thick elastic walls that expand with the contraction of ventricles The wave of blood is called a pulse Capillaries – thin, porous walls; where the exchange of gasses occurs; materials are forced out of the capillaries through blood pressure Veins – carry blood to heart; thinner walls than arteries; skeletal muscles aids the movement of blood

26. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Vessels • Capillary bed is a network of capillaries that are found in highly used tissues.

27. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Vessels • Flow of blood in veins is helped with contraction of skeletal muscles.

28. 2 Spreading the Effects of Smoke: The Cardiovascular System – Blood Vessels • Blood pressure is the force of the blood against blood vessel walls. • Hypertension is chronic high blood pressure that can be caused by atherosclerosis. • Tobacco smoke can lead to atherosclerosis by damaging the blood vessel walls.

29. 2 Spreading the Effects of Smoke: The Cardiovascular System The movement of materials through the cardiovascular system

30. 2 Spreading the Effects of Smoke – Smoke and Cardiovascular Disease Most cardiovascular damage from smoking is caused by nicotine. In high doses, nicotine is toxic to mammals. Nicotine increases production of LDL and decreases production of HDL, which can lead to atherosclerosis. Nicotine stimulates blood clot formation, which can result in stroke or heart attack. Most deaths due to smoking are due to cardiovascular disease.

31. Animation: The Heart and Blood Circulation Click “Go to Animation” / Click “Play”

32. 3 Removing Toxins From the Body: The Urinary System The major organs of the excretory system: kidneys, ureters, bladder, urethra

33. 3 Removing Toxins From the Body – Kidney Structure and Function Nephron functional unit of the kidneys, where filtration of wastes occurs Each kidney contains about 1,250,000 nephrons. Each kidney filters about 1000 liters of blood every day. Capillaries surround nephrons; wastes diffuse out of blood. Renal arteries bring blood to the kidneys to be filtered.

34. 3 Removing Toxins From the Body – Kidney Structure and Function There are four distinct phases of nephron function. Blood leaves the kidney via the renal vein.

35. 3 Removing Toxins From the Body – Smoking and the Excretory System Smoking has a severe impact on the excretory system. Probably related to increased blood pressure, which strains nephrons. Increased particulate load also stresses kidneys with increased waste removal. Smokers have 38% higher incidence of kidney cancer. Bladder cancer three times more common in smokers.

36. 3 Removing Toxins From the Body – Smoking and the Excretory System What we inhale affects our entire body.

37. Animation: The Mammalian Kidney Click “Go to Animation” / Click “Play”

38. What is the dome-shaped muscle that flattens to increase the volume of the chest cavity? diaphragm larynx trachea bronchi

39. What is the dome-shaped muscle that flattens to increase the volume of the chest cavity? diaphragm larynx trachea bronchi

40. What part of the brain regulates the rate of breathing? cerebellum cerebrum brain stem hypothalamus

41. What part of the brain regulates the rate of breathing? cerebellum cerebrum brain stem hypothalamus

42. Which of the following lists the flow of air into the lungs correctly? alveoli; bronchi; bronchioles bronchi; bronchioles; alveoli bronchioles; alveoli; bronchi bronchi; alveoli; bronchioles

43. Which of the following lists the flow of air into the lungs correctly? alveoli; bronchi; bronchioles bronchi; bronchioles; alveoli bronchioles; alveoli; bronchi bronchi; alveoli; bronchioles

44. What is the respiratory pigment in humans? red blood cells oxygen hemoglobin platelets

45. What is the respiratory pigment in humans? red blood cells oxygen hemoglobin platelets

46. In adults, all of the cellular components of blood are produced by stem cells in the _______. kidneys liver gall bladder bone marrow

47. In adults, all of the cellular components of blood are produced by stem cells in the _______. kidneys liver gall bladder bone marrow

48. True or False: Veins are the branching blood vessels that carry blood from the heart, and arteries are the converging vessels that bring it back. True False

49. True or False: Veins are the branching blood vessels that carry blood from the heart, and arteries are the converging vessels that bring it back. True False

50. What disease causes most of the deaths due to smoking? cardiovascular disease lung cancer emphysema mouth cancer