Respiratory - Gas Exchange, Oxygen Delivery, Exercise

Hypoxia

Low oxygen saturation of the body, not enough oxygen in the blood

Hypoxic hypoxia

low arterial PO2; caused by: high altitude, alveolar hypoventilation, decreased lung diffusion capacity, abnormal ventilation-perfusion ration

Anemic hypoxia

decreased amount of O2 bound to hemoglobin; caused by: anemia (low HB or altered HbO2 binding), CO poisoning

Ischemic hypoxia

reduced blood flow; cauased by: heart failure (whole body), shock (peripheral), thrombosis (single organ)

Histotoxic hypoxia

failure of cells to use O2 because of poisoned cells; caused by: cyanide and other metabolic poisons

Pressure of O2 in artery

95 mm Hg

Pressure of O2 in vein

40 mm Hg

Pressure of CO2 in artery

40 mm Hg

Pressure of CO2 in vein

46 mm Hg

pH in artery

7.4

pH in vein

7.37

surfactant

chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing

alveolar epithelium

simple squamous epithelium making up barrier of alveoli

fused basement membranes

between alveolar and endothelial cells

endothelial cells

cells lining the blood vessels

emphysema

The alveoli in the lungs are damaged and enlarged, so there is less surface area for gas exchange, causing breathlessness.

Fibrotic lung disease

Thickened alveolar membrane slows gas exchange. Loss of lung compliance may decrease alveolar ventilation

Pulmonary edema

fluid in the interstital space increases diffusion distance. arterial PO2 is low, but PCO2 might remain the same due to its solubility in water

Asthma

increased airway resistance decreases alveolar ventilations

Alveolar-arterial difference

the differnce between partial pressure of alveoli and partial pressure of artery

hypoxemia

deficient amount of oxygen in the blood

hypoventilation

decreased rate or depth of air movement into the lungs

pulmonary hypertension

elevated pulmonary pressure resulting from an increase in pulmonary vascular resistance to blood flow through small arteries and arterioles.

allosteric interaction

modification of enzyme config. resulting from the binding of an activator or inhibitor at a specific binding site on the enzyme

inspiration

breathing in; positive feeback loop; active movement

expiration

breathing out; lack of activity/relaxation