1. Respiratory physiology:

2. Respiration Ventilation: Movement of air into and out of lungs Ventilation: Movement of air into and out of lungs External respiration: Gas exchange between air in lungs and blood External respiration: Gas exchange between air in lungs and blood Transport of oxygen and carbon dioxide in the blood Transport of oxygen and carbon dioxide in the blood Internal respiration: Gas exchange between the blood and tissues Internal respiration: Gas exchange between the blood and tissues

3. Respiratory System Functions Gas exchange: Oxygen enters blood and carbon dioxide leaves Gas exchange: Oxygen enters blood and carbon dioxide leaves Regulation of blood pH: Altered by changing blood carbon dioxide levels Regulation of blood pH: Altered by changing blood carbon dioxide levels Voice production: Movement of air past vocal folds makes sound and speech Voice production: Movement of air past vocal folds makes sound and speech Olfaction: Smell occurs when airborne molecules drawn into nasal cavity Olfaction: Smell occurs when airborne molecules drawn into nasal cavity Protection: Against microorganisms by preventing entry and removing them Protection: Against microorganisms by preventing entry and removing them

4. Respiratory System Divisions Upper tract Nose, pharynx and associated structures Lower tract Larynx, trachea, bronchi, lungs

5. Nasal Cavity and Pharynx

6. Nose and Pharynx Nose Nose External nose External nose Nasal cavity Nasal cavity Functions Functions Passageway for air Passageway for air Cleans the air Cleans the air Humidifies, warms air Humidifies, warms air Smell Smell Along with paranasal sinuses are resonating chambers for speech Along with paranasal sinuses are resonating chambers for speech Pharynx Common opening for digestive and respiratory systems Three regions Nasopharynx Oropharynx Laryngopharynx

7. Larynx Functions Maintain an open passageway for air movement Epiglottis and vestibular folds prevent swallowed material from moving into larynx Vocal folds are primary source of sound production

8. Vocal Folds

9. Trachea Windpipe Divides to form Primary bronchi Carina: Cough reflex

10. Tracheobronchial Tree Conducting zone Conducting zone Trachea to terminal bronchioles which is ciliated for removal of debris Trachea to terminal bronchioles which is ciliated for removal of debris Passageway for air movement Passageway for air movement Cartilage holds tube system open and smooth muscle controls tube diameter Cartilage holds tube system open and smooth muscle controls tube diameter Respiratory zone Respiratory zone Respiratory bronchioles to alveoli Respiratory bronchioles to alveoli Site for gas exchange Site for gas exchange

11. Tracheobronchial Tree

12. Bronchioles and Alveoli

13. Alveolus and Respiratory Membrane

14. Lungs Two lungs: Principal organs of respiration Right lung: Three lobes Left lung: Two lobes Divisions Lobes, bronchopulmonary segments, lobules

15. Thoracic Walls Muscles of Respiration

16. Thoracic Volume

17. Pleura Pleural fluid produced by pleural membranes Acts as lubricant Helps hold parietal and visceral pleural membranes together

18. Ventilation Movement of air into and out of lungs Movement of air into and out of lungs Air moves from area of higher pressure to area of lower pressure Air moves from area of higher pressure to area of lower pressure Pressure is inversely related to volume Pressure is inversely related to volume

19. Alveolar Pressure Changes

20. Changing Alveolar Volume Lung recoil Lung recoil Causes alveoli to collapse resulting from Causes alveoli to collapse resulting from Elastic recoil and surface tension Elastic recoil and surface tension Surfactant: Reduces tendency of lungs to collapse Surfactant: Reduces tendency of lungs to collapse Pleural pressure Pleural pressure Negative pressure can cause alveoli to expand Negative pressure can cause alveoli to expand Pneumothorax is an opening between pleural cavity and air that causes a loss of pleural pressure Pneumothorax is an opening between pleural cavity and air that causes a loss of pleural pressure

21. Normal Breathing Cycle

22. Compliance Measure of the ease with which lungs and thorax expand Measure of the ease with which lungs and thorax expand The greater the compliance, the easier it is for a change in pressure to cause expansion The greater the compliance, the easier it is for a change in pressure to cause expansion A lower-than-normal compliance means the lungs and thorax are harder to expand A lower-than-normal compliance means the lungs and thorax are harder to expand Conditions that decrease compliance Conditions that decrease compliance Pulmonary fibrosis Pulmonary fibrosis Pulmonary edema Pulmonary edema Respiratory distress syndrome Respiratory distress syndrome

23. Pulmonary Volumes Tidal volume Tidal volume Volume of air inspired or expired during a normal inspiration or expiration Volume of air inspired or expired during a normal inspiration or expiration Inspiratory reserve volume Inspiratory reserve volume Amount of air inspired forcefully after inspiration of normal tidal volume Amount of air inspired forcefully after inspiration of normal tidal volume Expiratory reserve volume Expiratory reserve volume Amount of air forcefully expired after expiration of normal tidal volume Amount of air forcefully expired after expiration of normal tidal volume Residual volume Residual volume Volume of air remaining in respiratory passages and lungs after the most forceful expiration Volume of air remaining in respiratory passages and lungs after the most forceful expiration

24. Pulmonary Capacities Inspiratory capacity Inspiratory capacity Tidal volume plus inspiratory reserve volume Tidal volume plus inspiratory reserve volume Functional residual capacity Functional residual capacity Expiratory reserve volume plus the residual volume Expiratory reserve volume plus the residual volume Vital capacity Vital capacity Sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume Sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume Total lung capacity Total lung capacity Sum of inspiratory and expiratory reserve volumes plus the tidal volume and residual volume Sum of inspiratory and expiratory reserve volumes plus the tidal volume and residual volume

25. Spirometer and Lung Volumes/Capacities

26. Minute and Alveolar Ventilation Minute ventilation: Total amount of air moved into and out of respiratory system per minute Minute ventilation: Total amount of air moved into and out of respiratory system per minute Respiratory rate or frequency: Number of breaths taken per minute Respiratory rate or frequency: Number of breaths taken per minute Anatomic dead space: Part of respiratory system where gas exchange does not take place Anatomic dead space: Part of respiratory system where gas exchange does not take place Alveolar ventilation: How much air per minute enters the parts of the respiratory system in which gas exchange takes place Alveolar ventilation: How much air per minute enters the parts of the respiratory system in which gas exchange takes place

27. Physical Principles of Gas Exchange Partial pressure Partial pressure The pressure exerted by each type of gas in a mixture The pressure exerted by each type of gas in a mixture Dalton’s law Dalton’s law Water vapor pressure Water vapor pressure Diffusion of gases through liquids Diffusion of gases through liquids Concentration of a gas in a liquid is determined by its partial pressure and its solubility coefficient Concentration of a gas in a liquid is determined by its partial pressure and its solubility coefficient Henry’s law Henry’s law

31. Physical Principles of Gas Exchange Diffusion of gases through the respiratory membrane Diffusion of gases through the respiratory membrane Depends on membrane’s thickness, the diffusion coefficient of gas, surface areas of membrane, partial pressure of gases in alveoli and blood Depends on membrane’s thickness, the diffusion coefficient of gas, surface areas of membrane, partial pressure of gases in alveoli and blood Relationship between ventilation and pulmonary capillary flow Relationship between ventilation and pulmonary capillary flow Increased ventilation or increased pulmonary capillary blood flow increases gas exchange Increased ventilation or increased pulmonary capillary blood flow increases gas exchange Physiologic shunt is deoxygenated blood returning from lungs Physiologic shunt is deoxygenated blood returning from lungs

32. Oxygen and Carbon Dioxide Diffusion Gradients Oxygen Oxygen Moves from alveoli into blood. Blood is almost completely saturated with oxygen when it leaves the capillary Moves from alveoli into blood. Blood is almost completely saturated with oxygen when it leaves the capillary P0 2 in blood decreases because of mixing with deoxygenated blood P0 2 in blood decreases because of mixing with deoxygenated blood Oxygen moves from tissue capillaries into the tissues Oxygen moves from tissue capillaries into the tissues Carbon dioxide Moves from tissues into tissue capillaries Moves from pulmonary capillaries into the alveoli

33. Changes in Partial Pressures

34. Hemoglobin and Oxygen Transport Oxygen is transported by hemoglobin (98.5%) and is dissolved in plasma (1.5%) Oxygen is transported by hemoglobin (98.5%) and is dissolved in plasma (1.5%) Oxygen-hemoglobin dissociation curve shows that hemoglobin is almost completely saturated when P0 2 is 80 mm Hg or above. At lower partial pressures, the hemoglobin releases oxygen. Oxygen-hemoglobin dissociation curve shows that hemoglobin is almost completely saturated when P0 2 is 80 mm Hg or above. At lower partial pressures, the hemoglobin releases oxygen. A shift of the curve to the left because of an increase in pH, a decrease in carbon dioxide, or a decrease in temperature results in an increase in the ability of hemoglobin to hold oxygen A shift of the curve to the left because of an increase in pH, a decrease in carbon dioxide, or a decrease in temperature results in an increase in the ability of hemoglobin to hold oxygen

35. Hemoglobin and Oxygen Transport A shift of the curve to the right because of a decrease in pH, an increase in carbon dioxide, or an increase in temperature results in a decrease in the ability of hemoglobin to hold oxygen A shift of the curve to the right because of a decrease in pH, an increase in carbon dioxide, or an increase in temperature results in a decrease in the ability of hemoglobin to hold oxygen The substance 2.3-bisphosphoglycerate increases the ability of hemoglobin to release oxygen The substance 2.3-bisphosphoglycerate increases the ability of hemoglobin to release oxygen Fetal hemoglobin has a higher affinity for oxygen than does maternal Fetal hemoglobin has a higher affinity for oxygen than does maternal

36. Oxygen-Hemoglobin Dissociation Curve at Rest

37. Bohr effect:

38. Temperature effects:

40. Shifting the Curve

41. Transport of Carbon Dioxide Carbon dioxide is transported as bicarbonate ions (70%) in combination with blood proteins (23%) and in solution with plasma (7%) Carbon dioxide is transported as bicarbonate ions (70%) in combination with blood proteins (23%) and in solution with plasma (7%) Hemoglobin that has released oxygen binds more readily to carbon dioxide than hemoglobin that has oxygen bound to it (Haldane effect) Hemoglobin that has released oxygen binds more readily to carbon dioxide than hemoglobin that has oxygen bound to it (Haldane effect) In tissue capillaries, carbon dioxide combines with water inside RBCs to form carbonic acid which dissociates to form bicarbonate ions and hydrogen ions In tissue capillaries, carbon dioxide combines with water inside RBCs to form carbonic acid which dissociates to form bicarbonate ions and hydrogen ions

42. Transport of Carbon Dioxide In lung capillaries, bicarbonate ions and hydrogen ions move into RBCs and chloride ions move out. Bicarbonate ions combine with hydrogen ions to form carbonic acid. The carbonic acid is converted to carbon dioxide and water. The carbon dioxide diffuses out of the RBCs. In lung capillaries, bicarbonate ions and hydrogen ions move into RBCs and chloride ions move out. Bicarbonate ions combine with hydrogen ions to form carbonic acid. The carbonic acid is converted to carbon dioxide and water. The carbon dioxide diffuses out of the RBCs. Increased plasma carbon dioxide lowers blood pH. The respiratory system regulates blood pH by regulating plasma carbon dioxide levels Increased plasma carbon dioxide lowers blood pH. The respiratory system regulates blood pH by regulating plasma carbon dioxide levels

43. CO 2 Transport and Cl - Movement

46. Ventilation-perfusion coupling:

47. Respiratory Areas in Brainstem Medullary respiratory center Medullary respiratory center Dorsal groups stimulate the diaphragm Dorsal groups stimulate the diaphragm Ventral groups stimulate the intercostal and abdominal muscles Ventral groups stimulate the intercostal and abdominal muscles Pontine (pneumotaxic) respiratory group Pontine (pneumotaxic) respiratory group Involved with switching between inspiration and expiration Involved with switching between inspiration and expiration

48. Respiratory Structures in Brainstem

49. Rhythmic Ventilation Starting inspiration Starting inspiration Medullary respiratory center neurons are continuously active Medullary respiratory center neurons are continuously active Center receives stimulation from receptors and simulation from parts of brain concerned with voluntary respiratory movements and emotion Center receives stimulation from receptors and simulation from parts of brain concerned with voluntary respiratory movements and emotion Combined input from all sources causes action potentials to stimulate respiratory muscles Combined input from all sources causes action potentials to stimulate respiratory muscles Increasing inspiration Increasing inspiration More and more neurons are activated More and more neurons are activated Stopping inspiration Stopping inspiration Neurons stimulating also responsible for stopping inspiration and receive input from pontine group and stretch receptors in lungs. Inhibitory neurons activated and relaxation of respiratory muscles results in expiration. Neurons stimulating also responsible for stopping inspiration and receive input from pontine group and stretch receptors in lungs. Inhibitory neurons activated and relaxation of respiratory muscles results in expiration.

50. Modification of Ventilation Cerebral and limbic system Cerebral and limbic system Respiration can be voluntarily controlled and modified by emotions Respiration can be voluntarily controlled and modified by emotions Chemical control Carbon dioxide is major regulator Increase or decrease in pH can stimulate chemo- sensitive area, causing a greater rate and depth of respiration Oxygen levels in blood affect respiration when a 50% or greater decrease from normal levels exists

51. Modifying Respiration

52. Regulation of Blood pH and Gases

53. Herring-Breuer Reflex Limits the degree of inspiration and prevents overinflation of the lungs Limits the degree of inspiration and prevents overinflation of the lungs Infants Infants Reflex plays a role in regulating basic rhythm of breathing and preventing overinflation of lungs Reflex plays a role in regulating basic rhythm of breathing and preventing overinflation of lungs Adults Adults Reflex important only when tidal volume large as in exercise Reflex important only when tidal volume large as in exercise

54. Ventilation in Exercise Ventilation increases abruptly Ventilation increases abruptly At onset of exercise At onset of exercise Movement of limbs has strong influence Movement of limbs has strong influence Learned component Learned component Ventilation increases gradually Ventilation increases gradually After immediate increase, gradual increase occurs (4-6 minutes) After immediate increase, gradual increase occurs (4-6 minutes) Anaerobic threshold is highest level of exercise without causing significant change in blood pH Anaerobic threshold is highest level of exercise without causing significant change in blood pH If exceeded, lactic acid produced by skeletal muscles If exceeded, lactic acid produced by skeletal muscles

55. Effects of Aging Vital capacity and maximum minute ventilation decrease Vital capacity and maximum minute ventilation decrease Residual volume and dead space increase Residual volume and dead space increase Ability to remove mucus from respiratory passageways decreases Ability to remove mucus from respiratory passageways decreases Gas exchange across respiratory membrane is reduced Gas exchange across respiratory membrane is reduced