The Respiratory System

I. The Functional Anatomy of the Respiratory System A.Nose 1.Nares 2.Nasal cavity 3.Respiratory mucosa 4.Nasal conchae 5.Hard palate 6.Soft palate 7.Paranasal sinuses

B. Pharynx-throat 1.Common passageway 2.Three portions 3.Auditory tube 4.Tonsils a. pharyngeal (ad) b. palatine c. lingual

C. Larynx (voicebox) 1.Epiglottis 2.Thyroid cartilage 3.Vocal folds 4.Glottis 5.utube ube.com/watch? v=ajbcJiYhFKY

D. Trachea and bronchi 1. trachea C shaped ring 2. windpipe 3. ventral to esophagus 4. bronchi branch at carina 5. right bronchus wider shorter and straighter 6. Heimlich maneuver- tch?v=tEIiEAn7b- U&feature=player_detailpage

Slides of respiratory mucosa

E. Lungs 1.Apex and base 2.Pleural membranes 3.Pleural fluid 4.Pleurisy 5.Right lung three lobes 6.Left lung two lobes 7.Respiratory tree

F. Respiratory zone 1. zone where gas exchange occurs 2. respiratory bronchioles 3. alveolar ducts 4. alveolar sacs

G. Alveoli 1.Simple squamous 2.Pulmonary caps 3.Thinner sheet tissue paper 4.Alveolar pores 5.Simple diffusion meters squared (40 X skin) 7.Alveolar macrophages 8.Type II cells- pulmonary surfactant

Alveolar Tissue

II. Respiratory physiology A. Volume vs. pressure 1. gases conform to the shape of their container 2. in a large volume, the molecules of the gas are spread out 3. few collisions between the molecules and walls 4. larger volume lower pressure 5. volume decreases 6. more frequent collisions 7. higher pressures 8. gases flow (like water) from areas of higher to lower pressures

B. Events of inspiration-active process 1.Surface tension between pleural membranes 2.Diaphragm contracts 3.External intercostals contract 4.Voume increases 5.Pressures drop 6.Air pressure higher than pulmonary pressures 7.Air flows into lung

C. Exhalation or expiration 1.Passive process 2.Elastic recoil 3.Ribs return 4.Diaphragm relaxes 5.Lung volume drops 6.Air compressed 7.Expiration should be effortless 8.Asthma or chronic bronchitis 9.Forced expiration

D. Intrapleural pressure 1.Healthy lung intrapleural pressure is always negative 2.Prevents lung collapse 3.Air enters pulmonay space 4.Pneumothorax 5.Atelectasis

E. Respiratory volumes 1.Tidal volume IRV-3000ml 3.ERV-1200ml 4.Residual volume ml 5.Vital capacity= TV + IRV + ERV 6.Dead space volume = 150 ml

III. Control of respiration A. Breathing control centers 1. brain stem-pons and medulla 2. VRG-self-exciting inspiratory center 3. phrenic and intercostal nerves 4. normal breathing eupnea

B. Modifiers of respiratory effort 1.Higher brain centers 2.Stretch receptors 3.Receptors in muscles 4.Peripheral chemoreceptors

C. Chemical factors 1.Chemoreceptors monitor blood chemistry 2.Main stimulus is carbon dioxide and pH 3.Carbon dioxide transport 4.Main stimulant for respiratory efforts 5.Also tied to pH 6.Oxygen concentrations are of secondary importance

D. Interesting case of emphysema 1.COPD 2.Inspiration easier than expiration 3.Lungs retain some of each breath 4.Residual volume increases 5.Diaphragm flattens 6.Carbon dioxide is retained 7.Oxygen levels become main stimulant for respiratory effort 8.Oxygen must be administered at low levels 9.If administered at high levels as might be indicated, patient would stop breathing because the respiratory stimulus would be gone (low oxygen levels).

E. Hyperventilation 1.Young nervous women 2.Increased depth of breathing-what happens to carbon dioxide levels 3.What happens to pH 4.Cerebral vessels constrict 5.May get dizzy and faint 6.Breathing into paper bag