recall.... why is diffusion important? - gas exchange b/w a living cell & the environment always...
TRANSCRIPT
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