Gas Exchange and Transport

phys

3 regulated variables for breathing

oxygen, carbon dioxide, and pH

hypoxia

too little oxygen

hypercapnia

too much carbon dioxide

diffusion rate is proportionate to ___

surface area, concentration gradient, and barrier permeability

diffusion rate is inversely proportional to ___

distance travelled

surface area and barrier permeability issues

emphysema and fibrotic lung disease

diffusion distance issues

pulmonary edema and asthma

oxyhemoglobin saturation curves

show relationship between saturation and oxygen partial pressure

Bohr Effect

shifts to right due to decrease in pH

2, 3-BPG

shifts to right due to more oxygen being released to tissue

carbonic anhydrase

enzyme in red blood cells that converts carbon dioxide to bicarbonate ions

respiratory acidosis

too much carbon dioxide, build-up of hydrogen ions, increased pH, more acidic

central pattern generators

neuronal circuits that produce rhythmic motor patterns, located in brain stem

respiratory groups

dorsal, pontine, and ventral

dorsal respiratory group

located in nucleus tractus solitaries, controls muscles of inspiration

pontine respiratory group

located in pons, programmed to provide tonic medullary input for smooth respiratory rhythm

ventral respiratory group

controls active respiration and increased inspiration, keeps upper airways open

Pre-Botzinger Complex

pacemaker for respiration

most sensitive variables

pH and carbon dioxide

peripheral chemoreceptors location

carotid and aortic arteries (monitor pH and carbon dioxide)

central chemoreceptors location

medulla (monitor carbon dioxide)

Hering-Breuer Reflex

terminates inspiration to prevent lung over-inflation (more active in infants, but also during intense exercise)

alcohol consumption effect on protective reflexes

decreased alveolar ventilation

toddler tantrums effect on protective reflexes

carbon dioxide sensors will force them to breather

fetal hemoglobin

shift to left, 2 Alpha and 2 Gamma chains, increased affinity for oxygen, placenta is low oxygen environment

jaundice

build-up of bilirubin after mass destruction of fetal hemoglobin

altitude effects on respiration

adapts by creating more erythropoietin

cure for high altitude pulmonary edema

go back down in altitude