VI. O 2 and CO 2 transport A. O 2 i s c a r r i e d 2 w a y s 1. O n h e m o g l o b i n o f t h e R B C s 2. d i s s o l v e d i n b l o o d p l a s m a ( 1. 5 % ) B. C O 2 i s c a r r i e d 3 w a y s 1. D i s s o l v e d i n p l a s m a ( 7 - 8 % ) 2. O n h e m o g l o b i n o f t h e R B C s ( 2 0 % )
Carbon dioxide transport (cont.) 3. As the Bicarbonate Ion in the plasma (70%) HCO 3 - Combines with H 2 O to form carbonic acid.(H 3 CO 3 ) Used to buffer acid base
Hyperventilation: Too Little CO 2 - blow off too much CO 2 causes respiratory alkalosis. (dec Carbonic Acid – raises blood pH) Hypoventilation: too much CO 2 - don’t blow off enough CO 2 causes respiratory acidosis. (inc Carbonic Acid – lowers pH)
VII. Control of Respiration A. Medulla Oblongata- respiratory center B. Pons- provide smooth transition b/w inspiration and expiration. Cough: response to pulmonary irritant reflexes
D. Factors that Affect Breathing Chemoreceptor areas that detect CO 2 levels – carotid and aortic bodies Decrease in blood O 2 Increase in blood CO 2 Inflation reflex – prevents overfilling of lungs – controls depth of breathing Emotions, Fear, Pain
IX. Other Homeostatic Imbalances Cystic Fibrosis: Cystic fibrosis (CF) is a genetic disorder. The body produces abnormally thick and sticky mucus which builds up in the bronchi and in the pancreas. Lung infections and serious digestive problems are a result of this life-threatening disorder. Treatment – varies depending on symptoms. May include antibiotics when needed, preventative therapies such as vaccines, inhaled meds, oxygen therapy, enzyme therapy to thin mucus, chest percussion and postural drainage to help keep the airways clear.
Asthma Tightening and swelling of the airways. Akin to breathing through a straw with a pipe cleaner inside it. Triggers are many – allergens, common cold virus, exercise, cold air, etc…..
Apnea: not breathing (sleep apnea) Hypoxia: O2 deprivation at the tissue level. (CO) Tachypnea: fast breathing Eupnea: normal breathing Dyspnea: difficult or painful breathing
E m p h y s e m a : c a u s e – s m o k i n g ; d e s t r u c t i o n o f f i b e r s i n a i r p a s s a g e s t h a t h e l p k e e p p a s s a g e s o p e n, d e s t r u c t i o n o f a l v e o l i.
Oxygen Toxicity D i d y o u k n o w y o u t o o m u c h O 2 c a n b e t o x i c ? L e t ’ s t a k e a l o o k ….
What would happen if you breathed 100% Oxygen at normal pressure? Fluid accumulates in the lungs. Chest pains occur during deep breathing. The total volume of exchangeable air in the lung decreases by 17 percent. Mucus plugs local areas of collapsed alveoli -- The oxygen trapped in the plugged alveoli gets absorbed into the blood, no gas is left to keep the plugged alveoli inflated, and they collapse. Mucus plugs are normal, but they are cleared by coughing. If alveoli become plugged while breathing air, the nitrogen trapped in the alveoli keeps them inflated.
The astronauts in the Gemini and Apollo programs breathed 100 percent oxygen at reduced pressure for up to two weeks with no problems. In contrast, when 100 percent oxygen is breathed under high pressure (more than four times that of atmospheric pressure), acute oxygen poisoning can occur with these symptoms: Nausea Dizziness Muscle twitches Blurred vision Seizures/convulsions Such high oxygen pressures can be experienced by SCUBA divers using re-breathing devices, divers being treated for the bends in hyperbaric chambers or patients being treated for acute carbon monoxide poisoning. These patients must be carefully monitored during treatment.
COPD: Combination of Chronic Bronchitis and Emphysema Cause – in the US – most common cause is smoking. Other causes – long term exposure to lung irritants, whether environmental or workplace related Symptoms: persistant cough with a lot of mucus Shortness of breath (especially with physical activity) Wheezing Chest tightness Enlarged fibrous alveoli, followed by destruction. Airways and Lungs become floppy and useless. No cure. Worsens over time. Treatment = medications, rehab, and infection prevention.