O2 transport to Respiratory System as We Age Flashcards
What is the most important factor that determines how much O2 is bound to Hgb
partial pressure of O2
so higher pO2 = the more O2 binds w/ Hgb
How is O2 offloaded in the tissues
partial pressure of O2 decreases so it wants to dissociates from Hgb and go into the tissues
What are the 4 factors that affect the affinity of Hgb for O2 and what is there affect
- pH = decrease in pH causes affinity for O2 to decrease
- PCO2= increase in PCO2 causes affinity for O2 to decrease
- Temperature= increase in temp causes affinity for O2 to decrease
- 2,3 Biphoshoglycerate (BPG)= increased BPG causes affinity for O2 to decrease
What 3 forms are CO2 transported from highest amount to lowest amount
- Bicarbonate
- carboamino compounds
- Dissolved CO2
What is the most prevalent carboamino compound
carboaminohemoglobin
What enzyme is responsible for dissociating Bicarbonate into CO2 and H20
carbonic anhydrase
True or false the muscles of inspiration are involuntary
False the muscles are voluntary but they receive input from the involuntary nerve centers hat can make them contract if needed
Where in the brain are involuntary respiratory centers located
the medulla and the pons
What are the 3 groups of neurons that make of the respiratory center and what is their fxn
- Medullary rhythmicity center= sets the basic rhythm of breathing has an inspiratory and expiratory center
- Pneumotaxic center= inhibits inspiratory area of the medullary rhythmicity center so lungs do not become too full and helps transition between inhalation and exhalation
- Apneustic center= prolongs inspiration and helps coordinate the transition between inhalation and exhalation
What inhibit the apneustic center of the pons
pulmonary stretch receptors and the pnuemotaxic center
Why is voluntary control over breathing important
it prevents us from inhaling harmful substances (water, irritating gases..etc) if we perceive them
What happens when chemoreceptors sense increasing CO2 and H
The inspiratory center of the medullary is stimulated and overrides the cortical (voluntary) influences of breathing
What are the 2 locations of respiratory chemoreceptors
Central chemoreceptors= in or near the medulla oblongata
Peripheral chemoreceptors= in the aortic and caroid bodies
Central chemoreceptors respond to what compounds
H and CO2
Peripheral chemoreceptors respond to what compounds
H, O2, CO2
