Chapter 14 Lecture and Animation Outline To run the animations you must be in Slideshow View. Use the buttons on the animation to play, pause, and turn audio/text on or off. Please Note: Once you have used any of the animation functions (such as Play or Pause), you must first click on the slide s background before you can advance to the next slide. See separate PowerPoint slides for all figures and tables preinserted into PowerPoint without notes and animations. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1
Respiratory System Overview Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. 2
14.1 The Respiratory System 3
A. Introduction 1. Major function is gas exchange 2. Works with the cardiovascular system to accomplish: a. Pulmonary ventilation b. External respiration c. Internal respiration d. Transport of gases 3. Reason for the respiratory events provide oxygen for cellular respiration and remove carbon dioxide waste from cellular respiration 4
The respiratory tract 5
B. The respiratory tract 1. Introduction a. Nasal hairs, cilia, and mucus cleanse inhaled air 1) Lysozyme in the mucus helps to kill bacteria 2) Mucociliary escalator b. Inhaled air is warmed by superficial blood vessels lining the airways c. Air is moistened by the mucous membrane 6
2. The nose a. The only external portion of the respiratory system b. Air enters through the nostrils c. Contains two nasal cavities 1) Lined by a mucous membrane 2) Nasal conchae increase the surface area for moistening and warming inhaled air 3) Odor receptors located in the olfactory epithelium 7
The nose, cont d. Tears empty into the nasal cavities by way of the nasolacrimal canals e. Paranasal sinuses connect to the nasal cavities and act as resonating chambers for speech 8
The path of air 9
3. The pharynx (throat) a. Connects the nasal and oral cavities to the larynx b. Three parts: 1) Nasopharynx 2) Oropharynx 3) Laryngopharynx c. Tonsils provide the primary lymphatic tissue defense for breathing d. Passageway for both food and air 10
4. The larynx (voicebox) a. Cartilaginous passageway for air between the pharynx and trachea b. Houses the vocal cords 1) Mucosal folds that vibrate as air is expelled 2) Pitch regulated by the tension on the vocal cords and opening of glottis 3) Loudness depends on the amplitude of the vibrations c. Thyroid cartilage Adam s apple d. The epiglottis prevents food from entering the larynx 11
Anatomy of the larynx 12
5. The trachea (windpipe) a. Connects the larynx to the primary bronchi b. Ventral to esophagus c. C-shaped cartilaginous rings 1) Creates a patent airway 2) Allows for expansion of the esophagus d. Mucosal lining has pseudostratified ciliated columnar epithelium that forms the mucociliary escalator 13
Pseudostratified ciliated columnar epithelium 14
6. The bronchial tree a. The trachea divides into the right and left primary bronchi to enter the lungs b. The primary bronchi branch into secondary bronchi 1) Three for the right lung 2) Two for the left lung c. The secondary bronchi divide into tertiary bronchi d. Bronchioles are the smallest conducting airways; no cartilage e. Each bronchiole leads to air sacs called alveoli 15
C. The lungs 1. Lung structure a. Paired, cone-shaped organs b. Each lobe is divided into lobules c. Each lobule has a bronchiole and pulmonary arteries that serves many alveoli d. Elastic connective tissue helps with lung recoil when a person exhales 16
2. Pleura a. Double layered serous membrane 1) The visceral pleura adheres to the surface of the lung 2) The parietal pleura lines the inside of the thoracic cavity b. Produces a lubricating serous fluid that also creates surface tension between the layers 17
3. The alveoli a. Alveolar sacs are made up of simple squamous epithelium surrounded by blood capillaries b. Site of gas exchange c. Alveoli must stay open to receive inhaled air 1) Surfactant lowers the surface tension of water lining the alveoli preventing them from collapsing completely 2) Respiratory distress syndrome occurs in premature infants who lack surfactant d. Also contain dust cells, macrophages to defend against inhaled debris and pathogens 18
Gas exchange in the lungs 19
4. The respiratory membrane a. Facilitates rapid gas exchange b. Composed of juxtaposed alveolar epithelium and the capillary epithelium c. Extremely thin d. Large surface area (50-70m 2 ) 20
Alveolus and respiratory membrane 21
14.2 Mechanism of breathing 22
A. Ventilation 1. Introduction a. The manner in which air enters and exits the lungs b. Conditions to consider: 1) The lungs lie within the sealed-off thoracic cavity 2) The lungs adhere to the thoracic cavity wall by way of the pleurae; creates intrapleural pressure 3) A continuous column of air extends from the pharynx to the alveoli of the lungs 23
2. Inspiration a. Active phase of ventilation b. Diaphragm contracts and flattens c. External intercostal muscles contract, and the rib cage moves upward and outward d. Thoracic cavity volume increases, causing the lungs to increase in volume e. Air pressure within the alveoli (intrapulmonary pressure) decreases f. Air flows from an area of higher pressure (atmospheric pressure) to an area of lower pressure (within the lungs) until pressures are equal 24
Inspiration 25
3. Expiration a. Usually the passive phase of ventilation b. The diaphragm relaxes and resumes its dome shape c. The intercostal muscles relax and the rib cage moves down and in d. The volume of the thoracic cavity decreases and the lungs recoil e. Lung volume decreases and the intrapulmonary pressure increases f. Since intrapulmonary pressure is now greater than atmospheric pressure, air will flow out of the lungs until pressure are equal 26
Expiration 27
4. Maximum inspiratory effort a. Involves the accessory muscles of respiration 1) Erector spinae 2) Pectoralis minor 3) Scalene and sternocleidomastoid muscles b. Help increase the size of the thoracic cavity larger than normal c. Allows more air to be inspired 28
5. Forced expiration a. During heavy exercise, singing, etc. b. Involves contraction of abdominal wall muscles and the internal intercostal muscles c. Increased pressure in the thoracic cavity will expel more air 29
Alveolar Pressure Changes Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. 30
Mechanism of Breathing, cont 6. Spirometer instrument that records the volume of air exchanged during breathing 7. Spirogram shows the measurements recorded by a spirometer 31
B. Respiratory volumes 1. Tidal volume a. Normal, relaxed breathing b. About 500 ml 2. Vital capacity a. Maximum volume of air that can be inhaled plus the maximum volume of air that can be exhaled b. Depends on: 1) Inspiratory reserve volume a) Forced inspiration b) Increases the volume of air beyond the tidal volume by 2,900 ml 2) Expiratory reserve volume a) Forced expiration b) 1,400 ml 32
Respiratory volumes, cont 3. Residual volume a. Amount of air remaining in the lungs after a forced expiration b. About 1,000 ml 4. Dead air space 30% of the inspired air that does not reach the alveoli for exchange but remains in the passageways 33
Respiratory volumes 34
C. Control of ventilation 1. Controlled by a primary respiratory center in the medulla oblongata a. The phrenic nerve carries impulses to the diaphragm b. The intercostal nerves stimulate the external intercostal muscles c. Normal breathing rhythm also requires input from the pons 35
Nervous control of breathing 36
2. Nervous input a. Can influence depth and rate of breathing b. Cerebral cortex, limbic system, hypothalamus, and other brain centers c. Hering-Breuer reflex prevents overinflation of the lungs 37
3. Chemical input a. The respiratory center is sensitive to the levels of CO 2 and H + b. Chemoreceptors in the carotid and aortic bodies are sensitive to the level of oxygen in the blood 38
14.3 Gas exchange and transport 39
A. External respiration 1. Exchange of gases in the lungs between the air in the alveoli and the blood in the pulmonary capillaries 2. Oxygen a. Higher concentration in the alveoli b. Diffuses from the alveoli into the blood 3. Carbon dioxide a. Higher concentration in the blood b. Diffuses from the blood in the pulmonary capillaries to the alveoli 4. Partial pressure a. Amount of pressure exerted by each gas b. Symbolized as PO2 and PCO 2 c. Alveolar PO2 is higher than in the blood d. Blood P CO2 is higher than in the alveoli 40
B. Internal respiration 1. Exchange of gases in the tissues between the blood in systemic capillaries and tissue fluids 2. Oxygen a. Higher concentration in the blood b. Diffuses from the blood into the tissue fluid c. PO2 of the blood is higher than in tissue fluid 3. Carbon dioxide a. Higher concentration in the tissue fluid b. Diffuses from the tissue fluid into the blood c. P CO2 is higher in the tissue fluid than in the blood 41
External & internal respiration 42
Gas Exchange During Respiration Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. 43
C. Gas transport 1. Oxygen Transport a. 97-98% transported by hemoglobin in the red blood cells 1) Combined with oxygen oxyhemoglobin 2) Released oxygen deoxyhemoglobin b. Small amount (2-3%) transported in the plasma 44
2. Carbon dioxide transport a. As a dissolved gas in blood plasma and in the cytoplasm of red blood cells 10% b. Combined with globin portion of hemoglobin carbaminohemoglobin 30% c. Most is carried as bicarbonate ions 60% 1) Carbon dioxide combines with water to form carbonic acid in the RBC 2) Carbonic acid dissociates into hydrogen ions and bicarbonate ions 3) Excess H + combines with the globin portion of hemoglobin (reduced hemoglobin) 4) Bicarbonate ions diffuse out of red blood cells into the plasma in exchange for chloride ions chloride shift 45
3. ph a. The respiratory system helps regulate ph b. Bicarbonate/Carbonic acid buffer system is altered by breathing 1) Hypoventilation = increased CO 2 = decreased ph = acidosis (ph less than 7.35) 2) Hyperventilation = decreased CO 2 = increased ph = alkalosis (ph greater than 7.45) 46
14.4 Respiration and health 47
A. Upper respiratory tract infections 1. Can spread from the nasal cavities to the sinuses, middle ears, and larynx 2. Viral infections can lead to secondary bacterial infections 3. Strep throat a. Primary bacterial infection b. Caused by streptococcus pyogenes c. Can lead to a generalized upper respiratory infection 48
4. Sinusitis a. Infection of the cranial sinuses b. Develops when nasal congestion blocks openings to the sinuses c. Symptoms include: 1) Postnasal discharge 2) Facial pain d. Treatment depends on restoring proper drainage of the sinuses 49
5. Otitis media a. Bacterial infection of the middle ear b. Often a complication seen in children who have a nasal infection c. Pain is the primary symptom d. Other symptoms include: 1) Sense of fullness 2) Hearing loss 3) Vertigo 4) Fever e. Treatment is antibiotics and/or placement of tympanostomy tubes to drain fluid 50
URIs, cont 6. Tonsillitis a. Tonsils become inflamed and enlarged b. Tonsillectomy surgical removal of tonsils 7. Laryngitis a. Inflammation of the larynx b. Hoarseness leads to the inability to talk in an audible voice c. Causes by an upper respiratory infection or overuse 51
B. Lower respiratory tract disorders 1. Lower Respiratory Infections a. Bronchitis 1) Bacterial infection of the primary and secondary bronchi 2) Usually preceded by a viral URI b. Pneumonia 1) Viral or bacterial infection of the lungs 2) Bronchi and alveoli fill with thick fluid 3) Risk factors include: a) Advanced age b) Weakened immune system c) Smoking and being immobilized 4) May be localized in specific lobules of the lungs 52
Lower respiratory infections, cont c. Pulmonary tuberculosis 1) Caused by the tubercle bacillus bacterium 2) Lung tissue develops tubercles around the invading pathogens 3) Tuberculosis skin test can detect if a person has ever been exposed to the bacteria 53
Common bronchial & pulmonary diseases 54
2. Restrictive pulmonary disorders a. Vital capacity is reduced b. Lungs have lost their elasticity c. Pulmonary fibrosis 1) Fibrous connective tissue buildup in the lungs 2) Can be caused by inhaling silica, coal dust, asbestos, clay, cement, flour, fiberglass 55
3. Obstructive pulmonary disorders a. Air does not flow freely in the airways b. Maximal inhalation or exhalation time is greatly increased c. COPD chronic obstructive pulmonary disease 1) Develop slowly, over a long period of time 2) Recurrent 56
COPDs, cont 3) Chronic bronchitis a) Airways are inflamed and filled with mucus b) Bronchi have undergone degenerative changes c) Causes smoking and long-term exposure to pollutants 57
4) Emphysema a) Incurable disorder b) Alveoli are distended and walls are damaged and the surface area available for gas exchange is reduced c) Often preceded by chronic bronchitis d) Lungs have lost their elasticity e) Exhaling is difficult and residual volume increases f) Less oxygen reaches the heart and brain g) Surgical treatment of lung volume reduction and lung transplant 58
d. Asthma 1) Acute obstructive disorder 2) Disease of the bronchi and bronchioles 3) Marked by: a) Wheezing b) Breathlessness c) Sometimes a cough and expectoration of mucus 4) Airways are sensitive to irritants 5) Is not curable, but treatable with inhalers to control inflammation and stop muscle spasms 59
4. Lung cancer a. Linked to smoking b. Progressive steps in the development of lung cancer: 1) Thickening and callusing of the cells lining the primary bronchi 2) Cells with atypical nuclei appear in the callused lining 3) Cells break loose and penetrate other tissues (metastasis) c. Pneumonectomy surgical removal of a lobe of a lung or removal of the entire lung 60
Normal lungs vs. diseased lungs 61
14.5 Effects of aging 62
A. Effects of Aging 1. Respiratory fitness decreases with age 2. Maximum breathing capacities decline 3. Gas exchange in the lungs becomes less efficient 4. Respiratory membrane thickens 5. Ciliated cells of the trachea decline in number 6. Respiratory diseases are more common 63
14.6 Homeostasis 64
A. Gas exchange 1. Oxygen is needed by cells for cellular respiration 2. Carbon dioxide is a waste product of cellular respiration 65
B. Regulation of ph 1. Altering blood CO 2 levels 2. Increased CO 2, increases H +, and decreases ph (acidosis) 3. Decreased CO 2, decreased H +, and increases ph (alkalosis) 4. Hypoventilation build-up CO 2 5. Hyperventilation too much CO 2 leaving 66
C. Control of blood pressure 1. Assists in the renin-angiotensinaldosterone pathway 2. The lungs contain ACE (angiotensin converting enzyme) that converts angiotensin I into angiotensin II 3. Angiotensin II is a vasoconstrictor that raises blood pressure 67
D. Defense 1. Part of the 1 st line of defense 2. Mucus and cilia capture and remove pathogens 3. Assists immunity through the tonsils and alveolar dust cells 68
Human systems work together 69