CHAPTER 7.1 STRUCTURES OF THE RESPIRATORY SYSTEM

Transcription

1 CHAPTER 7.1 STRUCTURES OF THE RESPIRATORY SYSTEM Pages

2 DO NOW What structures, do you think, are active participating in the breathing process? 2

3 WHAT ARE WE DOING IN TODAY S CLASS Finishing Digestion Notes 3

4 The main functions of the respiratory system: bring oxygen to cells remove carbon dioxide from cells Respiration is the general term used to describe gas exchange

5 Main requirements for respiration: Large surface area for gas exchange Moist environment allows oxygen and carbon dioxide to dissolve in water

6 Stages of respiration: 1. Breathing 2. External respiration 3. Internal respiration 4. Cellular respiration 6

7 THE STAGES IN RESPIRATION 1. Breathing: Inspiration breathing in; inhaling. Moves air from the external environment to lungs inside body Expiration breathing out; exhaling. Moves air from lungs back to external environment

8 THE STAGES IN RESPIRATION 2. External respiration: exchange of oxygen and carbon dioxide between air and blood 3. Internal respiration: exchange of oxygen and carbon dioxide between cells and blood 4. Cellular respiration: energy releasing reactions taking place in the cells; sole means of providing energy for all cellular activities

9 THE RESPIRATORY TRACT

10 CHECK-IN QUESTION What is the main function of the human respiratory system? 10

11 THE UPPER RESPIRATORY TRACT The nasal passages: beginning of respiratory tract warms, moistens and cleans incoming air Specialized cells secrete mucous and trap foreign particles

12 Ciliated cells sweep mucous and foreign particles back up to nose and throat where they are expelled via coughing or sneezing

13 Pharynx (throat): passage way for air into the respiratory system Epiglottis: flap of cartilage behind tongue and larynx closes over trachea when swallowing prevents food from entering lungs when epiglottis is at rest, allows air to pass into lower respiratory tract

14 Larynx (voice box): made from cartilage contains vocal cords large gap between the vocal cords with normal breathing larynx contracts and the vocal cords are drawn together when speaking Air passing through narrow space causes the vocal cords to vibrate and make a sound

15 Vocal cords in action

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17 CHECK-IN QUESTION What are the different parts of the upper respiratory tract? 17

18 THE LOWER RESPIRATORY TRACT The trachea (windpipe) branches into the left and right bronchi (singular bronchus)

19 Each bronchus subdivides to create branching network of bronchioles Bronchi are supported by C-shaped cartilaginous rings that surround bronchus wall

20 Each lung divided into lobes The right lung has 3 lobes The left lung has 2 lobes, leaving space for heart Each lung made up of smaller lobules extending from each bronchiole

21 Lungs surrounded by thin, doublelayered membrane called pleural membrane Outer layer of membrane attaches to inside of chest cavity Inner layer of the membrane attaches to lungs Fluid fills space between two membranes, adhering them together

22 Connection between the two membranes allows for lungs to expand and contract with thoracic cavity

23 Each bronchiole ends in a cluster of tiny sacs called alveoli (singular alveolus)

24 Gas exchange occurs within alveoli during external respiration Each alveolus is contained within a membrane called an alveolar wall The alveolar wall is one cell thick and is surrounded by network of tiny capillaries Alveoli are lined with lubricating film (surfactant) that prevents alveoli from collapsing

25 EXIT SLIP Answer the following questions on a sheet of paper and place it in the biology 20 hand-in folder: How is external respiration different from internal respiration? Describe the roles of mucous and cilia in the upper respiratory tract. Identify the structures that make up the upper respiratory tract. Briefly describe the function of each structure. 25

26 7.2 BREATHING AND RESPIRATION Pages

27 WHAT ARE WE DOING IN TODAY S CLASS - objectives and the I can statements (should be in their notes as well) 27

28 THE STRUCTURES The diaphragm and intercostal muscles (rib muscles) control movement of air in and out of lungs Diaphragm domed shaped muscle separating the thoracic and abdominal cavity Intercostal muscles found between and along ribs

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30 THE MECHANICS OF BREATHING Inhalation: 1. External rib muscles and diaphragm contract. 2. Rib cage expands upward and outward 3. The volume of the thoracic cavity increases

31 THE MECHANICS OF BREATHING 4. The density of gas in the cavity decreases air pressure in the cavity decreases 5. Air moves from area high to low pressure (outside lungs to inside lungs) 6. Air rushes into lungs

32 Exhalation: 1. External rib muscles and diaphragm relax 2. The volume of thoracic cavity decreases 3. The density of gas in the cavity increases air pressure in the cavity increases 4. Air moves from areas of high to low pressure (inside the lungs to outside the lungs) 5. Air rushes out of the lungs

33 Mechanics of Breathing

34 RESPIRATORY VOLUME Under normal circumstances regular breathing does not use full lung capacity When your body needs more oxygen the volume of lungs can increase A spirograph is used to represent the amount of air that moves into and out of lungs with each breath

35 DO NOW Turn to your desk partner and discuss the following: Summarize the series of events that leads to the inhalation and exhalation of air. ** Please be ready to share your answer with the class! ** 35

36 The following terms are used in a spirograph: Tidal volume volume of air inhaled and exhaled in a normal breathing movement when body is at rest Inspiratory volume additional volume of air taken into the lungs, beyond a regular breath Expiratory reserve volume additional volume of air that can be forced out of lungs, beyond a regular breath

37 Vital capacity total lung capacity; total volume of gas that can be moved into or out of the lungs. Vital capacity = tidal volume + inspiratory reserve + expiratory reserve volume Residual volume amount of air that remains in lungs and passageways after a full exhalation. If this gas left the system, the lungs and passageways would collapse. The residual volume has little value for gas exchange because it is not exchanged with external environment

38 THE SPIROGRAPH

39 BALLOON DEMO 39

40 DEMO FOLLOW-UP QUESTIONS With your desk partner, discuss the following questions: 1. When a student takes a deep breath and inflates a balloon, what lung volume does the air in the balloon represent? Explain. 2. Is it possible to measure an individual s total lung volume by inflating a balloon? Explain why or why not. 3. Do you think that everybody can inflate a balloon to its fullest size? Why or why not? ** Please be ready to share your answer with the class! ** 40

41 EXTERNAL RESPIRATION External respiration takes place in lungs During external respiration, gases are exchanged between alveoli and blood in capillaries The walls of alveoli and capillaries are each one cell thick Gases easily diffuse through cell walls

42 Diffusion occurs from high! low concentration The air entering alveoli have a higher oxygen concentration than blood in the capillaries, oxygen diffuses from alveoli into capillaries

43 Blood in capillaries has higher concentration of carbon dioxide because it is returning from body tissues The carbon dioxide diffuses from capillaries into alveoli The carbon dioxide is exhaled into air

44 INTERNAL RESPIRATION Once oxygen and carbon dioxide have been exchanged, the blood moves through the heart and back to body tissues Oxygen and carbon dioxide are transported differently 99% of oxygen is carried by hemoglobin 1% is dissolved in blood plasma

45 Carbon dioxide is carried via: 23% by hemoglobin 7% in the plasma 70% is dissolved and carried in the blood as bicarbonate ion (HCO 3- )

46 The carbon dioxide reacts with water in the blood to form carbonic acid (H 2 CO 3 ) The reaction is reversed once the carbonic acid reaches the lung tissues CO 2 + H 2 O! H 2 CO 3! CO 2 + H 2 O 46

47 How can increased exercise causes an increase in breathing rate? 47

48 WHAT TO DO Answer the following questions on page 254 of the text: 1-4 a,c, 6, 8

49 THE SPIROGRAPH

50 Term tidal volume inspiratory reserve volume expiratory reserve volume vital capacity residual volume Definition Volume of air that is inhaled and exhaled in a normal breath. Additional volume of air that can be taken into lungs beyond tidal inhalation. Additional volume of air that can be forced out of the lungs beyond tidal inhalation. Total volume of gas that can be taken into and forced out of the lungs. It is calculated by adding the tidal volume + inspiratory reserve volume + expiratory reserve volume. Amount of gas that remains in the lungs and respiratory system passageways even after full exhalation. Is necessary so lungs do not collapse.

51 The typical tidal volume for humans is 500 ml. The typical expiratory reserve volume for humans is 1200 ml. The typical vital capacity for humans is 4800 ml.

52 7.3 RESPIRATORY HEALTH Pages

53 Upper Respiratory Tract Disorders: Tonsillitis Laryngitis Lower Respiratory Tract Disorders Bronchitis Pneumonia Pleurisy Asthma Emphysema

54 TONSILLITIS Viral infection of the tonsils Symptoms include swollen and red tonsils Treatment: Removal of tonsils in extreme cases Over the counter medication to treat for symptoms

55 LARYNGITIS Inflammation of the larynx (voice box) due to viral infection, allergies or overuse of voice Symptoms include sore throat and voice loss Treatment: Over the counter medication to treat for symptoms

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57 BRONCHITIS Acute bronchitis: Bacterial infection Treated with antibiotics Chronic bronchitis: Due to exposure to irritants and foreign bodies Loss of cilia increases risk of infection Treatment includes reduction to irritants (ie. quitting smoking) Symptoms include: inflamed airways, wet cough, wheezing

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59 PNEUMONIA Alveoli become inflamed and fill with fluids Lobular pneumonia: Due to bacterial infection Affects an entire lobe of lung Treated with antibiotics Bronchial pneumonia: Due to viral infection Affects patches throughout lungs Treated with anti-viral medication Symptoms include: difficulty breathing, low energy due to loss of gas exchange

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61 PLEURISY Swelling and irritation of the pleural membranes May be due to viral or bacterial infection Symptoms include a sharp stabbing pain in the chest in one region Treatment: antibiotics or anti-virals Reduce swelling and irritation

62 EMPHYSEMA Alveolar wall loses elasticity Surface area for gas exchange is reduced Moist common cause is smoking Symptoms include: difficulty breathing Treatment includes use of a low flow oxygen tank

63 ASTHMA Reduced air flow due to inflammation of bronchi and bronchioles Varies from mild to extreme Inflammation may be triggered by allergens, exercise, and stress Symptoms include difficulty breathing Treatment includes: Steroids and inhalers to reduce inflammation A nebulizer is often used in young patients

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65 CYSTIC FIBROSIS Genetic disorder affecting body s ability to control salt balance Thin fluid in lungs becomes thick mucous Sufferers are more prone to infection Results in low gas exchange Treatment: Medications to thin mucous Gene therapy healthy gene is inhaled deep into lungs

66 LUNG CANCER Due to carcinogens cancer causing agents Most common source of carcinogens are cigarettes Rapid growth of carcinoma (tumor) reduces surface area for gas exchange Other causes: Asbestos Radon Treatment may include removal of tumor depending on stage of cancer

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