Energy Production and Energy Consumption Flashcards
what is the equation for partial pressure
fractional concentration x pressure
eg what is the partial pressure in a normal room
PO2 = FiO2 x PB
0.2094 x 101.325 = 21 kPa
how does the kPa of O2 change from dry air, to humid air, to alveolar gas
21kpa
- 9 kpa
- 9 kpa
what are the 6 steps in the oxygen cascade
humidification alveolar gas alveolar capillary diffusion ventilation-perfusion mismatch and shunt tissue diffusion diffusion with cell
what is the pulmonary capillary PO2 vs arterial O2
- 9 in capillary
13. 6 in artery
what is the difference in PO2 in mean tissue vs in the mitochondria
5 Kpa in tissue
greater than 0.15 kPa
what is the definition of oxygen delivery
amount of oxygen leaving the heart in one minute
how do you calculate oxygen delivery (DO2)
check home screen
what is the definition of oxygen consumption
amount of oxygen used by the body in one minute VO2
what is the basal metabolic rate equal to
VO2 at rest
how do you measure oxygen consumption
Direct calorimetry 2. Indirect calorimetry: measure VO2: Arterio-venous CO2 difference Inspired-expired O2 volume difference
what are the normal values for oxygen consumption
200 ml/min
relative to body size BMR = 45 W/m^2
VO2 = 4.8 ml/min/kg
what factors affect VO2
age - peak at 0-2 years then falls throughout life
temperature - metabolic rate doubles very 10 degrees
exercise
what are the physiological responses of aenemia
increased 23-DPG shift and O2-Hb curve to the right
rescued blood flow to non-essential organs such as skin or the bowel
instead oxygen extraction
increased in cardiac output
in aenemia what is the average DO2
1000 ml/min
as altitude increases what happens to partial pressure of arterial oxygen arterial oxygen saturation haemoglobin conc arterial oxygen content
partial pressure of arterial oxygen decreases
arterial oxygen saturation decreases
Hb concentration increases
arterial oxygen content increases and then decreases past 6400m
what is the definition of the respiratory exchange ratio
the ration of carbon dioxide production VCO2 to oxygen consumption VO2
what is a normal RER value and what affects it
1
acid base balance
hyperventilation
metabolic fuel
what is the RER value for
carbs
fatty acids
protein
1
- 7
- 8
what are the three stages of generation of energy
glycolysis
tricarboxylic acid cycle
oxidative phosphorylation
where does the process of glycolysis occur and what does it do
occurs in cytoplasm
glucose to pyruvate or lactate
no oxygen required
2 ATP molecules per glucose
where does the TCA cycle occur and what is produced
occurs mostly in mitochondria
acetyl CoA (from glycolysis) to CO2
38 ATP molecules per glucose
where does oxidative phosphorylation occur and what does it do
occurs in mitochondria
NADh provides H+
H+ combines with O2 to produce water and ATP
what are the three causes of cellular hypoxia
anoxic - lack of O2 in the blood
Stagnant - lack of blood supply
Anaemic - lack of Hb
what diseases happens when you are anoxic, stagnant or stagnant and anaemic
respiratory failure
angina
angina and low Hb
