Respiratory System (gas Exchange) Flashcards
WHat is the pH level of arterial blood?
7.4 (7.38-7.42)
What is the pH level of venous blood
7.37
What happens during Emphysema?
-destruction of alveoli = less surface area for gas exchange
What happens during fibrotic lung disease?
- thickened alveolar membrane slows gas exchange
- loss of lung compliance may decrease alveolar ventilation
What happens during pulmonary edema?
- fluid in interstitial space increases diffusion distance.
- Arterial PCO2 may be normal to higher CO2 solubility in water
What happens during asthma?
-increase airway resistance decreases alveolar ventilation
What happens to a body undergoing hypoxia?
Types?
Body/ region deprived of O2
1) hypoxia hypoxia: low arterial PO2
- high altitude, alveolar hypoventilation
2) anemic hypoxia: decreased total amount of O2 bound to hemoglobin
- blood loss, anemia, carbon monoxide poisoning
3) ischemic hypoxia: reduced blood flow
- heart failure, shock
4) histotoxic hypoxia: failure of cells to use O2 because cells have been poisoned
- cyanide
How is HbO2 (oxyhemoglobin) measured?
Total blood O2 content = dissolved O2 + O2 bound to Hb
What is the total O2 carrying capacity during Oxygen transport in blood without hemoglobin?
3 ml O2/L blood
What is the total O2 carrying capacity during Oxygen transport at normal PO2 in blood with hemoglobin?
200 ml O2/L blood
What is the amount of oxygen bound to hemoglobin depend on?
1) plasma O2
- % saturation of HB
2) amount of hemoglobin
- total number of Hb binding sites
How is % saturation of HbO2 calculated?
(Amount of O2 bound/ maximum that could be bound) x 100
Important:resting cell; 40 (3 O2 bound) and alveoli;100(4 O2 bound)
How many binding sites does hemoglobin have?
4
How much oxygen in blood is bound to hemoglobin in RBC compared to plasma?
98%: bound to hemoglobin
2%: dissolved in plasma
How many oxygens are delivered by 1 hemoglobin?
1
