1. Do Now
What is the major function of the respiratory system? Major Organs?
What is the relationship between the cardiovascular system and the respiratory system?

2. Chapter 13
Respiratory System

3. The trillions of cells in our body require an abundant and continuous supply of oxygen to carry out their vital functions.

4. The cardiovascular system and the respiratory system share the responsibility for supplying the body with oxygen and disposing of carbon dioxide.

5. The respiratory system organs oversee the gas exchanges that occur between the blood and the external environment.

6. Transportation of gases is carried out by the cardiovascular system.

7. Functional Anatomy of the Respiratory System

8. Organs of the Respiratory system
Nose
Pharynx
Larynx
Trachea
Bronchi and their smaller branches
Lungs
BLT  PLT

11. The lungs contain the alveoli which are terminal air sacs.
Gas exchange only occurs in the alveoli.
Therefore all other organs of the respiratory system are conducting passageways that allow air to reach the lungs.

12. The Organs of the Respiratory System

14. Functions of the Conducting Passageways
Allows air to reach the lungs

16. 1. Nose Air enters through the nostrils or external nares.
The nose contains two nasal cavities.
Special ciliated cells in the upper reaches of the nasal cavity act as odor receptors.

17. Tear glands drain into the nasal cavity.
The palate separates the nasal cavity from the oral cavity.
Function – filter, warm and moisten the air

18. 2. Pharynx
The pharynx is a muscular passageway commonly called the throat.
It is a common passageway for food and air.
The pharynx in superior to the larynx and trachea.
Tonsils are located in the pharynx.

19. 3. Larynx The larynx is also known as the voicebox.
Function of the larynx: sound production
The epiglottis: a flap of tissue that prevents food from passing into the larynx

20. Parts of the larynx form folds called the vocal folds or the true vocal cords which: vibrate with expelled air giving us the ability to speak
Glottis – opening to the larynx – epiglottis covers

21. 4. Trachea The trachea is also known as the windpipe
The trachea is lined with cilia. The cilia beat in the direction opposite of the incoming air.

22. They propel mucus: loaded with dust particles and other debris, away from the lungs to the throat where it can be swallowed or spat out

23. The trachea is rigid because it has C shaped cartilaginous rings
Tracheotomy – when as incision is made in the trachea to allow air to pass around a blockage

25. 5. Bronchi The trachea divides into the right and left primary bronchi
The bronchi laid into the lungs
The bronchi branch into a great number of smaller passageways known bronchioles

26. During an asthma attack:
Smooth muscle lining the bronchioles constricts and movement of air through the narrowed tubes results in the characteristic wheezing

27. By the time air has reached the bronchi it is:
Warm
Cleansed of most impurities
Well humidified

28. 6. Lungs The paired lungs are fairly large organs
They occupy almost the entire thoracic cavity
The primary bronchi go into the lungs where they subdivide into smaller and smaller branches (secondary and tertiary bronchi). They finally end in the smallest of the conducting passageways the bronchioles.

31. The bronchioles end in alveoli or air sacs.
The alveoli make up the respiratory zone
The lungs are cone-shaped organs. The right lung has three lobes and the left lung has 2 lobes. The left lung has 2 since the heart is on that side and takes up some of the space.

32. Capillary Network Diagram

33. Each alveolar sac is made up of simple squamous epithelium surrounded by blood capillaries. Gas exchange occurs in the capillaries.
This layer of tissue and the capillary net create the respiratory membrane (air/blood barrier). Air flows by one side and blood flows by on the other side. Gas exchange occurs by simple diffusion.

35. There are approximately 300 million (alveoli)
There are approximately 300 million (alveoli). Their surface area is at least 40X that of the skin.
The lungs are mostly air spaces so they are light and usually float in water – soft and spongy
Macrophages (WBC) wander in and out of the alveoli picking up bacteria, carbon particles and other debris.

36. Mechanisms of Breathing
Respiration: the complete process of supplying oxygen to body cells for aerobic cellular respiration and the reverse process of ridding the body of oxygen

37. Respiration includes the following components:

38. 1. Breathing Inspiration – entrance of air into the lungs
Expiration – exit of air from the lungs

39. 2. External Respiration
Exchange of the gases oxygen and carbon dioxide between air and blood
Occurs in the lungs

40. 3. Internal Respiration
Exchange of the gases oxygen and carbon dioxide between blood and tissue fluid
Occurs in the body cells

41. 4. Cellular Respiration
Production of ATP in cells

42. Mechanics of Breathing

43. Breathing is a completely mechanical process that depends on volume changes occurring in the thoracic cavity
Volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure

44. Ventilation
The manner in which air enters and exits the lungs

45. To understand ventilation it is necessary to:
There is a continuous column of air from the pharynx to the alveoli of the lungs
The lungs lie within the sealed-off thoracic cavity. The rib cage forms the top and sides. The diaphragm forms the floor of the thoracic cavity.

46. 3. The lungs are enclosed by 2 serous membranes called pleural membranes. One layer is attached to the rib cage and diaphragm and the other layer is attached to the lungs. The two layers are very close and are only separated by a little fluid. The pressure in the pleural space is lower than atmospheric pressure.

47. Inspiration is Active
Inspiration is triggered by the respiratory center. Impulses are sent by way of the nerves to the diaphragm and the muscles of the rib cage known as intercoastals.

48. When relaxed the diaphragm is domed shaped but when it contracts it lowers.

49. Nerves also stimulate the intercostal muscles to contract causing the rib cage to move upward and outward

50. When the diaphragm contracts and the rib cage moves up and out, the thoracic cavity increases in size. This causes the lungs to expand and air to move in from the nose or mouth.

51. Expiration is usually passive
When the nerves stop sending signals, the diaphragm relaxes and resumes its dome shape.
The abdominal organs press up against the diaphragm and the rib cage moves down and inward
This causes the elastic lungs to recoil and air to be pushed out.

52. External and Internal Respiration
The principles of diffusion alone govern whether oxygen or carbon dioxide enters or leaves the blood

53. External Respiration cleanses the blood
External respiration refers to the exchange of gases between air in the alveoli and blood in the pulmonary capillaries

54. External Respiration occurs in the lungs.
Carbon dioxide diffuses out of the blood in the lungs.
Oxygen diffuses into the blood in the lungs.

55. Internal respiration cleanses tissue fluid
Internal respiration occurs in the body cells
Oxygen diffuses out of the blood and into the tissues.
Carbon dioxide diffuses out the tissues and into the blood

58. Respiratory Sounds

59. As air flows in and out of the respiratory passageways it produces two recognizable sounds that can be picked up with a stethoscope.

60. Bronchial Sounds – produced by air rushing through the large respiratory passageways
Vesicular sounds – as air fills the alveoli

61. Diseased respiratory tissue, mucus or pus can produce abnormal sounds such as rales (a rasping sound) or wheezing (a whistling sound)

62. Respiration and Health

63. Bronchitis: Acute and Chronic

64. Acute Caused by: secondary bacteria infection
Results in: heavy mucous discharge with much coughing
Treatment: antibiotics

65. Chronic
Caused by: smoking – second hand smoke – irritation to the lining of the bronchi
Results in: frequent coughing, increased risk of respiratory infections
Treatment - none

66. Pneumonia Caused by: bacteria or virus infection of the lungs
Results in: lobes fill with fluid become non-functional
Treatment - antibiotics

67. Pulmonary Tuberculosis
Caused by: Tubercle bacillus – bacteria
Results in: cysts in the lungs, alveoli burst and replace by inelastic connective tissue
Treatment: antibiotics – some strains are now resistant

68. Emphysema
Caused by: destruction of lung tissue – damage and collapse of lung tissue
Results in: ballooning or inflation of the lungs due to trapped air, breathless cough, surface for gas exchange decreases, not enough oxygen to hear and body
Treatment: none

69. Smoker's Lung - tar coated, causing emphysema

70. Lung Cancer Caused by: smoking
Results in: thickening of bronchi cells, loss of cilia, dust and bacteria enter
Treatment: removal of lung piece

71. The End