1. Respiratory System
Biol 105
Lecture 18
Chapter 14

2. Outline - Respiratory System
Function of the respiratory system
Parts of the respiratory system
Mechanics of breathing
Regulation of breathing
Disorders of the respiratory system

3. Respiratory system Function
The function of the respiratory system is to bring in oxygen to the body and remove carbon dioxide.

4. The Respiratory System
Breathing moves air in and out of the lungs.
External respiration is the exchange of oxygen and carbon dioxide between the lungs and the blood.
Gas transport moves oxygen and carbon dioxide between the lungs and the body tissues.
Internal respiration is the exchange of oxygen and carbon dioxide between blood and the body tissues.
Oxygen transport
Carbon dioxide transport
Lungs
Gas diffusion
Gas diffusion
Tissue
Figure 14.1

5. This type of tissue covers and lines body parts
Connective
Epithelial
Muscle
Nervous

6. Cells lining respiratory tract
Lined by pseudostratified ciliated columnar epithelial cells. The cilia sweeps mucus, germs and debris toward the throat.
Mucas produced by goblet cells.
Smoking damages the ciliated cells
8-4

7. The Respiratory System
Figure 14.4a

8. Ciliated cells in respiratory tract

9. The Respiratory System
Figure 14.3

10. The Respiratory System
UPPER RESPIRATORY SYSTEM
Sinuses
• Cavities in skull
• Lighten head
• Warm and moisten air
• Filters, warms, and moistens air
Nasal cavity
• Produces mucus
• Filters, warms, and moistens air
• Olfaction
Pharynx
• Passageway for air and food
RESPIRATORY MUSCLES
• Cause breathing
Intercostal muscles
Diaphragm
• Muscle sheet between chest and abdominal cavities with a role in breathing
• Move ribs during breathing
Figure 14.2 (1 of 2)

11. The Respiratory System
LOWER RESPIRATORY SYSTEM • Exchanges gases
Epiglottis
• Covers larynx during swallowing
Larynx
• Air passageway
• Prevents food and drink from entering lower respiratory system
• Produces voice
Lungs
• Structures that contain alveoli and air passageways
• Allow exchange of oxygen and carbon dioxide between atmosphere and blood
Bronchi
• Two branches of trachea that conduct air from trachea to each lung
Trachea
• Connects larynx with bronchi leading to each lung
• Conducts air to and from bronchi
Bronchioles
• Narrow passageways to conduct air from bronchi to alveoli
Alveoli
• Microscopic chambers for gas exchange
Figure 14.2 (2 of 2)

12. moisten the air entering the lungs smell
1. Nasal cavity
Functions:
filter
warm
moisten the air entering the lungs
smell
8-3

13. Mucus membranes - secrete sticky mucus to trap germs & debris.
1. Nasal cavity
Parts of the nasal cavity:
Mucus membranes - secrete sticky mucus to trap germs & debris.
Contains olfactory receptor cells for the sense of smell
Sinuses – air filled cavities, warm and moisten air
8-3

14. 2. Pharynx
Functions - is a passageway for air, liquids, and food. (swallowing begins here). Connects the nasal cavity to the esophagus and the larynx
Tonsils are found here – lymphatic tissue that protects against infection
8-4

15. Functions Connects the pharynx to the trachea
3. Larynx
Functions
Connects the pharynx to the trachea
Contains vocal cords used to generate sound
Prevents food from entering lower respiratory tract
8-4

16. Structure made from cartilage
3. Larynx
Structure made from cartilage
Epiglottis closes the trachea when swallowing
8-4

17. FIGURE 14.5a
The larynx, commonly called the voice box or Adam's apple, is an adjustable entryway to the trachea and the source of the voice. (a) The epiglottis is open during breathing but covers the opening to the larynx during swallowing to prevent food or drink from entering the trachea. (b) The vocal cords are the folds of connective tissue above the opening of the larynx (the glottis) that produce the voice.

18. FIGURE 14.5b
The larynx, commonly called the voice box or Adam's apple, is an adjustable entryway to the trachea and the source of the voice. (a) The epiglottis is open during breathing but covers the opening to the larynx during swallowing to prevent food or drink from entering the trachea. (b) The vocal cords are the folds of connective tissue above the opening of the larynx (the glottis) that produce the voice.

19. Windpipe held open by concentric rings of cartilage
4. Trachea
Windpipe held open by concentric rings of cartilage
Function – Connects the larynx to the bronchi.
8-4

20. Trachea leads to the bronchial tree:
Bronchi (bronchus)
Bronchioles
Alveoli (alveolus).
8-4

21. The Respiratory System
Figure 14.7

22. 7. Alveoli
Sacs at the end of the bronchioles, they are surrounded by blood capillaries .
Function: It is here that the oxygen diffuses across the membrane into the capillaries, and carbon dioxide goes from the capillaries to the inside of the lungs.
8-6

23. Alveoli Lungs - have about 300 million alveoli
The structure of the alveoli increases surface area of lung
For alveoli to function properly they are coated with phospholipid molecules called surfactant that keep them open

24. Alveoli
Figure 14.8

25. The Respiratory System
Table 14.1 (1 of 2)

26. The Respiratory System
Table 14.1 (2 of 2)

27. What cells secrete mucus
Cilliated columnar epi
goblet
Squamous epi
osteocytes

28. The tube connecting the larynx to the primary bronchi is
pharynx
trachea
bronchioles
alveoli

29. Common passageway for air, food and drink
pharynx
trachea
bronchioles
alveoli

30. Conduct air from the trachea to the bronchioles
pharynx
trachea
bronchi
alveoli

31. Gas exchange takes place here
pharynx
trachea
bronchioles
alveoli

32. Which cavity is the lung located in?
Abdominal
Pericardial
Pleural
Dorsal

33. Inhalation Inhalation Air flow Rib cage moves up and out
Intercostal muscles contract
Diaphragm contracts and flattens
Diaphragm contracts
The chest cavity increases in size, and pressure within the lungs decreases.
The lungs expand, and air moves in.
(a)
Figure 14.9a

34. Inhalation
When the diaphragm and intercostal muscles contract, the volume of the thoracic cavity increases, causing the pressure in the lungs to decrease
Inhalation is also called inspiration

35. Exhalation Exhalation Air flow Rib cage moves down and inward
Intercostal muscles relax
Diaphragm relaxes and moves upward
Diaphragm relaxes
The chest cavity decreases in size, and pressure within the lungs increases.
The lungs recoil, and air moves out.
(b)
Figure 14.9b

36. Exhalation Exhalation = Expiration
When the same muscles relax, volume of the thoracic cavity decreases, pressure in the lungs increase

37. Air Volumes
The volume of air inhaled or exhaled during a normal breath is called the tidal volume
Tidal volume is usually around 500 ml
The volume of air moved into and out of the lungs is an indication of health

38. Air Volumes Inspiratory reserve volume = forced inhalation volume
Expiratory reserve volume = forced exhalation volume
Residual volume is the amount of air left in the lungs after forced exhalation
Vital capacity is the amount of air brought in and out of the lungs during forced breathing

39. Air Volumes 6000 Inspiratory reserve (forced inhalation) volume
Total lung capacity
5000
Vital capacity
4000
Tidal volume
Lung Volume (ml)
3000
Expiratory reserve (forced exhalation) volume
2000
1000
Residual volume
Figure (1 of 2)

40. Gas Exchanges in the Body
Remember that O2 enters and CO2 leaves the lungs = External respiration
Then O2 and CO2 is exchanged between the blood vessels and tissues = Internal Respiration
This gas exchange is due to diffusion
8-14

41. Oxygen Transport Oxygen is transported on Hemoglobin.
When Oxygen is bound to hemoglobin, then it is called Oxyhemoglobin
8-15

42. Carbon Dioxide Transport
CO2 is transported dissolved in the plasma (10%)
CO2 is bound to hemoglobin (20%)
CO2 is converted to bicarbonate ions (70%)
8-14

43. Bicarbonate ions
CO2 + H2O H2CO H+ + HCO3-
Carbonic anhydrase
8-14

44. Diffusion of Gasses: Alveoli and Capillaries
Figure (2 of 2)

45. Diffusion of Gasses: Capillaries and Tissues
Figure (1 of 2)

46. Regulation of Breathing
Normally we breath ventilations per minute.
This rate is controlled by the medulla oblongata region of the brain. Nerves transmit signal to the diaphragm and muscles.
Chemoreceptors in the medulla oblongata and arteries detect levels of CO2 and O2 in the blood, controlling the rate and depth of breathing.
8-12

47. Respiratory Disorders
Common cold
Flu
Pneumonia
Strep Throat
Tuberculosis
Bronchitis
Asthma
Emphysema
Lung Cancer
8-16

48. Respiratory Disorders – Common Cold
The common cold - Caused by several types of viruses.
Symptoms: runny nose, sore throat, sneezing, nasal discharge
Treatment: rest and plenty of fluids
Prevention: wash your hands

49. Respiratory Disorders - Flu
The flu is caused by the Influenza viruses but there are many variants of these viruses
Symptoms: Similar to colds but appear suddenly and more severe. Usually have fever and chills, may have muscle aches, headache, and weakness.
Treatment and prevention – same as cold
Can take drugs to ease symptoms and antiviral medications may ease symptoms

50. Respiratory Disorders - Pneumonia
Pneumonia is an inflammation of the lungs that causes fluid to accumulate in the alveoli, reducing gas exchange
Usually caused by a viral or bacterial infection
Symptoms: fever, chills, chest pain, cough, shortness of breath.
Treatment depends on cause – bacteria can be treated with antibiotics.

51. Respiratory Disorders Strep throat
Strep throat is caused by Streptococcus bacteria
Can lead to rheumatic fever which can damage heart and kidney disease
Symptoms: Sore throat accompanied by swollen glands and fever
Treatment: antibiotics

52. Respiratory Disorders - Tuberculosis
Tuberculosis is caused by a bacteria = mycobacterium tuberculosis.
Bacteria spread through airborne transmission
Our body encapsulates the bacteria with a fibrous capsule made of connective tissue to try to protect itself, capsule is called tubercles

53. Respiratory Disorders - Tuberculosis
Symptoms: similar to flu, weight loss, tired, dry cough.
Treatment: Antibiotics must be taken for 6 months to 2 years – some people to stop early – leads to antibiotic resistant strains of bacteria

54. Respiratory Disorders - Bronchitis
Bronchitis is an inflammation of the mucous membrane of the bronchi
Caused by viruses, bacteria, or chemical irritation
Symptoms: Inflammation results in the production of excess mucus, which triggers a deep cough
Treatment: Depends on cause

55. Respiratory Disorders - Asthma
The smooth muscles surrounding the bronchi spasm – causing the bronchi to constrict, making it hard to breathe
Causes and triggers: allergies, colds, exercise, stress

56. Respiratory Disorders - Emphysema
Emphysema is caused by the destruction of alveoli, usually by smoking
Reduction in the surface area available for gas exchange and the increased dead air space results in shortness of breath
Treatment - no cure, can supplement with oxygen and drugs can dilate airways.

57. Respiratory Disorders - Emphysema
Figure 14.14

58. Lung Cancer
Lung Cancer is the result of uncontrolled cell division forms a tumor
The smoke irritates the lining of the bronchi.
The cilia that normally function to clear dust and particles from the lungs are destroyed.
Often caused by inhaled carcinogens, including those found in tobacco smoke. Between 85 – 90% of lung cancer is from smoking.

59. Lung Cancer
Lung cancer is more common in men, but as more women are smoking, the rate of lung cancer in women is rising. Women are more at risk
Many compounds in the smoke are cancer promoters, they trigger the progression of cancer in cells.
8-16

60. Effects of Smoking
The 5-year survival rate is 13%. Smoking can cause cancers of other parts of the respiratory system.
8-16

61. Effects of Smoking on Pregnancy
Cigarette smoke contains CO, the fetal blood has a higher affinity for CO than the mothers blood, so CO builds up in the fetuses body.
Nicotine is also passed into the fetus, stimulating the developing nervous system.
Men smoking can damage the DNA in their sperm and pass genetic mutations to their offspring.
8-16

62. Figure 8.11

63. Lung Cancer
Figure 14.15

64. Figure: 14A-01a
Title:
Cigarette smoking reduces life expectancy.
Caption:
(a) Smoking causes more than 400,000 deaths each year in the United States, more people each year than the combined number of deaths due to AIDS, alcohol, drugs, car accidents, murder, and suicide. These data are from a report from the Centers for Disease Control and Prevention in The number of deaths from cigarette smoking have increased since then, but the relative importance of each cause of death remains similar.

65. Figure: 14A-04
Title:
Tobacco use and lung cancer.
Caption:
Lung cancer usually takes about 20 years to develop. Notice that the number of deaths from lung cancer increases and decreases with tobacco use with about a 20-year delay. The lung cancer death rate of females is lower than that of men because there are fewer female smokers than there are male smokers. Source: Death rates: U.S. Mortality Public Use Tapes, , U.S. Mortality Volumes, , National Center for Health Statistics, Centers for Disease Control and Prevention, Cigarette consumption: U.S. Department of Agriculture,

66. Figure: 14A-07
Title:
Death rate due to heart disease among nonsmokers and smokers.
Caption:
Notice that the death rate from heart disease increases with the number of cigarettes smoked per day. People who smoke over a pack per day have more than twice the risk of death due to heart disease than do people who have never smoked. In any case, a smoker who successfully quits is much less likely to die of heart disease than if the smoking habit continues.

67. What is the smoking policy on campus?
You can smoke anywhere
You can smoke anywhere outside
You can smoke at designated spots
No smoking on campus

68. Do you think smoking should be allowed on campus?
Yes No

69. Do you smoke?
Never
Used to, but quit
Smoke, but trying to quit
Smoke

70. Important Concepts Read Ch 15
What is the function of the respiratory system?
What is the location and function of the all the parts of the respiratory system?
What are the parts of the nasal cavity and their functions?
What are the parts of the larynx and their functions?

71. Important Concepts
What cell types lines the trachea, what are their functions, be able to discus how smoking effects this tissue?
Where does the exchange of gases occur in the lungs?
What cavity contains the lungs?
What controls the rate of breathing?
Be able to discuss the mechanics of breathing?

72. Important Concepts How is oxygen carried in the blood?
How is carbon dioxide carried in the blood, know all the ways, and the which is the predominate mode? (You don’t need to know the chemical equation of bicarbonate formation)
What is the diaphragm and what is its function?

73. Important Concepts
Be able to discuss the disorders of the respiratory system including the description, symptoms, cause, and treatments.
How does smoking effect pregnancy?

74. Definitions
Goblet cells, sinuses, epiglottis, surfactant, diaphragm, intercostal muscles, Inhalation/inspiration, exhalation/expiration tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume, vital capacity, hemoglobin, oxyhemoglobin, chemoreceptors, tubercles, antibiotic resistant