Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slides – Seventh Edition Elaine N. Marieb Chapter 13 The Respiratory System Lecture Slides in PowerPoint by Jerry L. Cook

Respiratory Sounds Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sounds are monitored with a stethoscope  Bronchial sounds – produced by air rushing through trachea and bronchi  Vesicular breathing sounds – soft sounds of air filling alveoli

External Respiration Slide 13.32a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Oxygen movement into the blood  The alveoli always has more oxygen than the blood  Oxygen moves by diffusion towards the area of lower concentration  Pulmonary capillary blood gains oxygen

External Respiration Slide 13.32b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Carbon dioxide movement out of the blood  Blood returning from tissues has higher concentrations of carbon dioxide than air in the alveoli  Pulmonary capillary blood gives up carbon dioxide  Blood leaving the lungs is oxygen-rich and carbon dioxide-poor

Gas Transport in the Blood Slide 13.33a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Oxygen transport in the blood  Inside red blood cells attached to hemoglobin (oxyhemoglobin [HbO 2 ])  A small amount is carried dissolved in the plasma

Gas Transport in the Blood Slide 13.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Carbon dioxide transport in the blood  Most is transported in the plasma as bicarbonate ion (HCO 3 – )  A small amount is carried inside red blood cells on hemoglobin, but at different binding sites than those of oxygen

VI. O 2 and CO 2 transport A. O 2 i s c a r r i e d 2 w a y s 1. O n h e m o g l o b i n o f t h e R B C s 2. d i s s o l v e d i n b l o o d p l a s m a ( 1. 5 % ) B. C O 2 i s c a r r i e d 3 w a y s 1. D i s s o l v e d i n p l a s m a ( % ) 2. O n h e m o g l o b i n o f t h e R B C s ( 2 0 % )

Carbon dioxide transport (cont.) 3. As the Bicarbonate Ion in the plasma (70%) HCO 3 - Combines with H 2 O to form carbonic acid.(H 3 CO 3 ) Used to buffer acid base

Internal Respiration Slide 13.34a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Exchange of gases between blood and body cells  An opposite reaction to what occurs in the lungs  Carbon dioxide diffuses out of tissue to blood  Oxygen diffuses from blood into tissue

Exchange at Tissue Level

Exchange at Alveolar Level

Internal Respiration Slide 13.34b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.11

External Respiration, Gas Transport, and Internal Respiration Summary Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.10

Hyperventilation: Too Little CO 2 - blow off too much CO 2 causes respiratory alkalosis. (dec Carbonic Acid – raises blood pH) Hypoventilation: too much CO 2 - don’t blow off enough CO 2 causes respiratory acidosis. (inc Carbonic Acid – lowers pH)

VII. Control of Respiration A. Medulla Oblongata- respiratory center B. Pons- provide smooth transition b/w inspiration and expiration. Cough: response to pulmonary irritant reflexes

Neural Regulation of Respiration Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Activity of respiratory muscles is transmitted to the brain by the phrenic and intercostal nerves  Neural centers that control rate and depth are located in the medulla  The pons appears to smooth out respiratory rate  Normal respiratory rate (eupnea) is 12–15 respirations per minute  Hypernia is increased respiratory rate often due to extra oxygen needs

Neural Regulation of Respiration Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.12

D. Factors that Affect Breathing Chemoreceptor areas that detect CO 2 levels – carotid and aortic bodies Decrease in blood O 2 Increase in blood CO 2 Inflation reflex – prevents overfilling of lungs – controls depth of breathing Emotions, Fear, Pain

IX. Other Homeostatic Imbalances Cystic Fibrosis: Cystic fibrosis (CF) is a genetic disorder. The body produces abnormally thick and sticky mucus which builds up in the bronchi and in the pancreas. Lung infections and serious digestive problems are a result of this life-threatening disorder. Treatment – varies depending on symptoms. May include antibiotics when needed, preventative therapies such as vaccines, inhaled meds, oxygen therapy, enzyme therapy to thin mucus, chest percussion and postural drainage to help keep the airways clear.

Asthma Tightening and swelling of the airways. Akin to breathing through a straw with a pipe cleaner inside it. Triggers are many – allergens, common cold virus, exercise, cold air, etc…..

Apnea: not breathing (sleep apnea) Hypoxia: O2 deprivation at the tissue level. (CO) Tachypnea: fast breathing Eupnea: normal breathing Dyspnea: difficult or painful breathing

E m p h y s e m a : c a u s e – s m o k i n g ; d e s t r u c t i o n o f f i b e r s i n a i r p a s s a g e s t h a t h e l p k e e p p a s s a g e s o p e n, d e s t r u c t i o n o f a l v e o l i.

Oxygen Toxicity D i d y o u k n o w y o u t o o m u c h O 2 c a n b e t o x i c ? L e t ’ s t a k e a l o o k ….

What would happen if you breathed 100% Oxygen at normal pressure? Fluid accumulates in the lungs. Chest pains occur during deep breathing. The total volume of exchangeable air in the lung decreases by 17 percent. Mucus plugs local areas of collapsed alveoli -- The oxygen trapped in the plugged alveoli gets absorbed into the blood, no gas is left to keep the plugged alveoli inflated, and they collapse. Mucus plugs are normal, but they are cleared by coughing. If alveoli become plugged while breathing air, the nitrogen trapped in the alveoli keeps them inflated.

The astronauts in the Gemini and Apollo programs breathed 100 percent oxygen at reduced pressure for up to two weeks with no problems. In contrast, when 100 percent oxygen is breathed under high pressure (more than four times that of atmospheric pressure), acute oxygen poisoning can occur with these symptoms: Nausea Dizziness Muscle twitches Blurred vision Seizures/convulsions Such high oxygen pressures can be experienced by SCUBA divers using re-breathing devices, divers being treated for the bends in hyperbaric chambers or patients being treated for acute carbon monoxide poisoning. These patients must be carefully monitored during treatment.

COPD: Combination of Chronic Bronchitis and Emphysema Cause – in the US – most common cause is smoking. Other causes – long term exposure to lung irritants, whether environmental or workplace related Symptoms: persistant cough with a lot of mucus Shortness of breath (especially with physical activity) Wheezing Chest tightness Enlarged fibrous alveoli, followed by destruction. Airways and Lungs become floppy and useless. No cure. Worsens over time. Treatment = medications, rehab, and infection prevention.

Factors Influencing Respiratory Rate and Depth Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Physical factors  Increased body temperature  Exercise  Talking  Coughing  Volition (conscious control)  Emotional factors

Factors Influencing Respiratory Rate and Depth Slide 13.39a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chemical factors  Carbon dioxide levels  Level of carbon dioxide in the blood is the main regulatory chemical for respiration  Increased carbon dioxide increases respiration  Changes in carbon dioxide act directly on the medulla oblongata

Factors Influencing Respiratory Rate and Depth Slide 13.39b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chemical factors (continued)  Oxygen levels  Changes in oxygen concentration in the blood are detected by chemoreceptors in the aorta and carotid artery  Information is sent to the medulla oblongata

Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD) Slide 13.40a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Exemplified by chronic bronchitis and emphysema  Major causes of death and disability in the United States

Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD) Slide 13.40b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Features of these diseases  Patients almost always have a history of smoking  Labored breathing (dyspnea) becomes progressively more severe  Coughing and frequent pulmonary infections are common

Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD) Slide 13.40c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Features of these diseases (continued)  Most victimes retain carbon dioxide, are hypoxic and have respiratory acidosis  Those infected will ultimately develop respiratory failure

Emphysema Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Alveoli enlarge as adjacent chambers break through  Chronic inflammation promotes lung fibrosis  Airways collapse during expiration  Patients use a large amount of energy to exhale  Overinflation of the lungs leads to a permanently expanded barrel chest  Cyanosis appears late in the disease

Chronic Bronchitis Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mucosa of the lower respiratory passages becomes severely inflamed  Mucus production increases  Pooled mucus impairs ventilation and gas exchange  Risk of lung infection increases  Pneumonia is common  Hypoxia and cyanosis occur early

Chronic Obstructive Pulmonary Disease (COPD) Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 13.13

Lung Cancer Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Accounts for 1/3 of all cancer deaths in the United States  Increased incidence associated with smoking  Three common types  Squamous cell carcinoma  Adenocarcinoma  Small cell carcinoma

Sudden Infant Death syndrome (SIDS) Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Apparently healthy infant stops breathing and dies during sleep  Some cases are thought to be a problem of the neural respiratory control center  One third of cases appear to be due to heart rhythm abnormalities

Developmental Aspects of the Respiratory System Slide 13.47a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lungs are filled with fluid in the fetus  Lungs are not fully inflated with air until two weeks after birth  Surfactant that lowers alveolar surface tension is not present until late in fetal development and may not be present in premature babies

Developmental Aspects of the Respiratory System Slide 13.47b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Important birth defects  Cystic fibrosis – oversecretion of thick mucus clogs the respiratory system  Cleft palate

Aging Effects Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Elasticity of lungs decreases  Vital capacity decreases  Blood oxygen levels decrease  Stimulating effects of carbon dioxide decreases  More risks of respiratory tract infection

Respiratory Rate Changes Throughout Life Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Newborns – 40 to 80 respirations per minute  Infants – 30 respirations per minute  Age 5 – 25 respirations per minute  Adults – 12 to 18 respirations per minute  Rate often increases somewhat with old age