J. Hinson Human Anatomy and Physiology January 2007 Respiratory System J. Hinson Human Anatomy and Physiology January 2007

I. Introduction Passages; air Respiration a. Breathing b. Exchange of gases c. Transport of gases d. Exchange of gases Cellular Respiration http://www.biology.eku.edu/RITCHISO/breathingmechanics.gif http://www.youtube.com/watch?v=HiT621PrrO0

II. Anatomy Two Tracts Upper respiratory system: nose, nasal cavity, sinuses, pharynx, and larynx Lower respiratory system: trachea, bronchial tree, and lungs http://www.greenfacts.org/images/glossary/respiratory_tract.jpg

II. Anatomy B. Nose 1. Bones: nasal and vomer; cartilage http://www.catgofire.com/random/nose.jpg II. Anatomy B. Nose 1. Bones: nasal and vomer; cartilage 2. external nares or nostrils a. hairs

II. Anatomy C. Nasal Cavity 1. nasal septum divides 2. nasal conchae support mucous membrane a. epithelium contains goblet cells (i) moisturize and trap dust 3. blood vessels II. Anatomy C. Nasal Cavity

II. Anatomy D. Paranasal sinuses 1. maxillary, frontal, ethmoid, and sphenoid; reduce weight; voice 2. lining continuous with nasal cavity http://www.entconsent.co.uk/ENTcons/images/sinuses.jpg

II. Anatomy E. Pharynx 1. throat 2. Function: food, air, sound http://www.yksd.com/DistanceEdCourses/YKSDbiology/lessons/ThirdQuarterLessons/Chapter08/8-3/images/pharynx.jpg

II. Anatomy F. Larynx 1. airway enlargement 2. Functions: a. air http://www.throat-cancer-symptoms.com/assets/images/imgTCShome-larynx.jpg II. Anatomy F. Larynx 1. airway enlargement 2. Functions: a. air b. filter c. voice box 3. thyroid, cricoid, and epiglottic cartilages http://img.intelihealth.com/i/L/Larynx.gif

II. Anatomy G. Trachea (windpipe) 1. cylindrical tube splits into bronchi 2. C-shaped cartilages http://dtc.pima.edu/~biology/160alpha/lesson16/trachea.jpg

II. Anatomy H. Bronchial Tree 1. branched airways 2. Primary bronchi 3. Secondary bronchi: branches 4. Tertiary bronchi: to bronchioles 5. Alveolar ducts to alveoli for gas exchange http://d-mis-web.ana.bris.ac.uk/calnet/medthor3/image/lungs%20&%20bronchial%20tree-schematic%20diag2.jpg

II. Anatomy I. Lungs 1. cone-shaped a. R: 3 lobes b. L: 2 lobes 2. mediastinum separates 3. visceral pleura and parietal pleura a. pleural space between http://www.mylungtransplant.pwp.blueyonder.co.uk/lungs.jpg

III. Pulmonary Ventilation (BREATHING!) Movement of external air into and out of the bronchial tree and alveoli Inspiration (inhalation) Atmospheric Pressure is the force that causes movement Normal air pressure = 760 mmHg Occurs when pressure inside alveoli reduced As diaphragm moves down, thorax expands (volume ٨), thus pressure decreases. Lungs expand Surface tension of the pleural membrane also aids. Surfactant decreases the tendency for alveoli collapse. http://www.youtube.com/watch?v=RmMcqnXqrvA&feature=related

III. Pulmonary Ventilation (BREATHING!) Expiration (exhalation) Forces of expiration come from the elastic recoil of tissue and from surface tension within the alveoli. Aided by the contraction of the internal intercostals and abdominal wall muscles, but is typically a passive process. http://images.google.com/imgres?imgurl=http://kvhs.nbed.nb.ca/gallant/biology/negative_pressure_breathing.jpg&imgrefurl=http://kvhs.nbed.nb.ca/gallant/biology/negative_pressure_breathing.html&usg=__d9DzVi0HeSZS9axdzwINM0YYvos=&h=501&w=800&sz=104&hl=en&start=4&um=1&itbs=1&tbnid=FNea2SWymTszhM:&tbnh=90&tbnw=143&prev=/images%3Fq%3Dbreathing%26hl%3Den%26safe%3Dactive%26rlz%3D1T4GGLL_enUS343US343%26um%3D1 http://www.youtube.com/watch?v=SWJHSTAWTCk&feature=related

IV. Respiratory Air Volumes/Capacities Spirometry: measure of air volumes Respiratory Volumes: Tidal: normal breathing; ~ 500 cc Inspiratory Reserve: additional inhaled; ~ 3000 cc Expiratory Reserve: additional exhale; ~ 1100 cc Residual: remainder after forceful exhale: ~ 1200 cc Remains in lungs and mixed with new air http://www.youtube.com/watch?v=iWFEbjMPqxo

IV. Respiratory Air Volumes/Capacities Respiratory Capacities: Vital: max air exhaled after deepest breath; ~ 4600 cc Inspiratory: vol. of air inhaled after tidal vol. exhaled; ~ 3500 cc Functional Residual: vol. remaining after tidal vol. exhaled; ~ 2300 cc Total Lung Capacity: total air possible to hold; 5800 cc

V. Clinical Terms Apnea Asphyxia Dyspnea Hemothorax Hypoxia http://www.daviddarling.info/images/pneumothorax_radiograph.gif Apnea Asphyxia Dyspnea Hemothorax Hypoxia Pneumothorax http://easypediatrics.com/wp-content/uploads/2012/08/cyanosis.jpg http://www.nhlbi.nih.gov/health/health-topics/images/pleurisy.jpg

VI. Breathing Control Normal breathing is rhythmic & involuntary. Controlled via brain stem’s respiratory center http://www.elu.sgul.ac.uk/rehash/guest/scorm/309/package/content/images/brain_respiratory_center.jpg

VI. Breathing Control Rate and depth influenced by: Chemicals Chemosensitive areas (brain): respond to change in CO2 and H+…rate increases when stimulated Chemoreceptors (bvs): respond to change in O2…rate increases when O2 low Stretching Tissues Inflation reflex regulates depth Stretch receptors in pleura, bronchioles, and alveoli prevent overinflation Emotional State: fear and pain increase rate Hyperventilation: lowers CO2 (increases pH)

VII. Alveolar Gas Exchange http://www.youtube.com/watch?v=XTMYSGXhJ4E Occurs at alveoli (tiny, distal air sacs) Membrane consists of alveolar and capillary walls to allow gas exchange between alveolar air and blood via… Diffusion high to low partial pressure (determined by concentration of gas) O2 to blood…CO2 to alveoli Air: 78% N; 21% O2; .04% CO2 PO2 = 160 mmHg; PCO2 = 0.3 mmHg

VII. Gas Transport Blood transports between lungs and body. http://www.youtube.com/watch?v=eor6EK_JP40 Blood transports between lungs and body. Oxygen Transport 98% by hemoglobin Oxyhemoglobin: iron binds to O2 in hemoglobin More O2 released as CO2 increases, the blood becomes more acidic (H+ high) or blood temperature increases. Carbon Dioxide Transport Carried in solution, on hemoglobin, or as bicarbonate (in plasma) Carbonic anhydrase speeds reaction bw CO2 and H2O to form carbonic acid…dissociates to H+ and bicarb.