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 O2 & CO2 gases on either side of cell membrane)

3) Diffusion distance

How is Oxygen Transported in Blood?Oxygen (O2)

Alveolar wall

Capillary cells

Blood plasma

Red Blood Cells

Haemoglobin (Hb)- Greatly increases our oxygen carrying capacity

- Most O2 binds to Hb forming oxyhemoglobin O2 + Hb Oxyhemoglobin - Oxyhemoglobin is transported to the body cells (i.e. muscle cell) where O2 is released

- CO2 is picked up from the body cells for transport back to the lungs

How is Carbon Dioxide Transported in Blood?- CO2 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 (H2CO3)

carbonic anhydraseI. CO2 + H2O H2CO3 (blood plasma)

II. H2CO3 H+ + HCO3- (RBC’s)

III. H+ + HCO3- CO2 + H2O (alveoli)

CO2 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

AsthmaCauses Symptoms Treatment(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 + emphysemaCauses Symptoms Treatment(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”)Causes Symptoms Treatment(s)- Flu virus - fever

- dry cough- sore throat- runny nose- muscle & joint aches

- Antiviral drugs if diagnosed within first 24-48 hrs

Tuberculosis (TB)Causes Symptoms Treatment(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

PneumoniaCauses Symptoms Treatment(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 FibrosisCauses Symptoms Treatment(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 InhibitorsWhat is it? What does it treat?- A group of drugs that interfere with the production of chemicals that cause inflammation

- Asthma- COPD

Bronchial ThermoplastyWhat is it? What does it treat?-A procedure that decreases the amount of constriction of the airways during an asthma attack

- Asthma- COPD

Artificial LungsWhat 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 CO2 from the blood while a small amount of O2 back into the blood.

- Patients waiting for lung transplants

Lung TransplantsWhat 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