Recall...

Why is diffusion important? - Gas exchange b/w a living cell & the environment always takes place by diffusion across a moist surface. - The rate of diffusion depends on 3 major factors: 1) Surface area of the cell membrane. 2) Concentration gradient (difference in concentrations of O 2 & CO 2 gases on either side of cell membrane) 3) Diffusion distance

How is Oxygen Transported in Blood? Oxygen (O 2 ) Alveolar wall Capillary cells Blood plasma Red Blood Cells

Haemoglobin (Hb) - Greatly increases our oxygen carrying capacity - Most O 2 binds to Hb forming oxyhemoglobin O 2 + Hb Oxyhemoglobin - Oxyhemoglobin is transported to the body cells (i.e. muscle cell) where O 2 is released - CO 2 is picked up from the body cells for transport back to the lungs

How is Carbon Dioxide Transported in Blood? - CO 2 is produced in body cells as a waste product of aerobic cellular respiration & must be removed. - It is transported in the blood in 3 different ways: 1) 7% dissolves in blood plasma 2) 20% attaches to Hb to form carbaminohemoglobin 3) 73% reacts with water in plasma to form carbonic acid (H 2 CO 3 ) carbonic anhydrase I. CO 2 + H 2 O H 2 CO 3 (blood plasma) II. H 2 CO 3 H + + HCO 3 - (RBC’s) III. H + + HCO 3 - CO 2 + H 2 O (alveoli)

CO 2 Transport (chemical reactions)

Respiratory Disorders & Technologies Disorders: Asthma Chronic Obstructive Pulmonary Disease (COPD) Influenza Tubeculosis Pneumonia Cystic Fibrosis Technologies: FLAP Inhibitors Bronchial Thermoplasty Artificial Lungs Lung Transplants

Asthma CausesSymptomsTreatment(s) - Chronic, long-term inflammation of the lining of bronchi & bronchioles - Lining of airway swells reducing airflow to lungs - Overproduction of mucus contributes to reduced airflow - “Triggers”  cigarette smoke, dust, cold air, exercise, allergens (i.e. Pollen, animal dander) - Coughing - Wheezing - Tightness in chest - Shortness of breath - Not curable - Avoiding triggers - Inhalers (“puffers”) provide medications that dilate (open up) bronchi & bronchioles

COPD = bronchitis + emphysema CausesSymptomsTreatment(s) - Mostly caused by cigarette smoke - Other causes include long-term exposure to pollution, dust, or fumes - Genetic disorders can cause emphysema - Similar to asthma - Not curable - medications, lifestyle changes - oxygen therapy - lung transplants in extreme cases

Influenza (“the flu”) CausesSymptomsTreatment(s) - Flu virus- fever - dry cough - sore throat - runny nose - muscle & joint aches - Antiviral drugs if diagnosed within first hrs

Tuberculosis (TB) CausesSymptomsTreatment(s) - Bacterial infection - Infects lungs first, but if not treated can affect nervous system, bones, joints, & spine - Most cases occur in developing countries - coughing - chest pain - weight loss - night sweats - coughing up blood - sometimes no symptoms - Vaccination for prevention - 6 month course of antibiotics if you get infected Myobacterium tuberculosis

Pneumonia CausesSymptomsTreatment(s) - Lung infection caused by bacteria, viruses, or fungi -Inflammation of lining of bronchi, bronchioles, & alveoli - Pus & mucus accumulates in alveoli preventing gas exchange - Fever - Cough - Shortness of breath - yellow & green phlegm - Antibiotics treat bacterial pneumonia - Infants & elderly especially susceptible due to weakened immune systems

Cystic Fibrosis CausesSymptomsTreatment(s) - Genetic disorder - Gene that controls mucus production is defective - Thick & sticky mucus clogs airways reducing airflow - Also affects digestion (pancreatic function) - Persistent cough - Excess mucus - More susceptible to lung infections (i.e. Pneumonia) - Not curable - Antibiotics treat other infections - Ongoing physiotherapy - Lung transplants

FLAP Inhibitors What is it?What does it treat? - A group of drugs that interfere with the production of chemicals that cause inflammation - Asthma - COPD Bronchial Thermoplasty What is it?What does it treat? -A procedure that decreases the amount of constriction of the airways during an asthma attack - Asthma - COPD

Artificial Lungs What is it?What does it treat? - A temporary system (iLA Membrane Ventilator) that connects to the body via two femoral blood vessels in the leg. - Removes CO 2 from the blood while a small amount of O 2 back into the blood. - Patients waiting for lung transplants

Lung Transplants What is it?What does it treat? - Surgical procedure where a disease lung is replaced with part of or a whole healthy lung from a donor. - Blood & tissue type must be a close match to the recipient to prevent organ rejection. - COPD - Cystic Fibrosis