CHP 18 - GAS EXCHANGE

define hypoxia

too little oxygen (stimuli for new RBC)

define hypercapnia

increased concentrations of CO2

what is partial pressure pf O2

how much oxygen is present in a certain area

what is partial pressure of CO2

how much CO2 is present in a certain area

what is daltons law

the total pressure of a mixture of gases is the sum of pressures of individual gases

formula for partial pressure

Pgas in humid air = (Patm - PH2O0 x % of gas

VO2 equation/ ficks equation

VO2 = Q x A - V O2difference

what is VO2

ability to intake, transport and utilize oxygen

2 ways oxygen is transported in blood

1. bound to hemoglobins

2. dissolved in plasma

how much O2 can a fully saturated hemoglobin carry at rest

20 mL O2/L blood

4 factors that affect O2- Hb binding

1. pH

2. temperature

3. CO2

4. 2,3 - diphosphoglycerate

what is the primary driver of increased ventilation

• increased partial pressure of CO2

• (hypercapnia)

how is CO2 transported in blood

1. bound to hemoglobin

2. dissolved in plasma

3. combines with bicarbonate ions

what regulates ventilation

1. respiratory neurons in medulla control inspiratory and expiratory muscles

2. rhythmic pattern of breathing arises from a neural network of spontaneously discharging neurons

3. ventilation is subject to continuous modulation by chemoreceptor and mechanoreceptor- linked reflexes