Respiration IV Flashcards
Describe the inter pleural pressure compared to the base
inter pleural pressure is more negative at apex compared to base
Where is the apex of the lung
top of the lung
Why are pressures in the lung different
posture, gravity
Where is ventilation greater in the lung?
base
TRUE or FALSE - sub-atmospheric pressure is the same throughout the inter pleural space
FALSE
Where is the starting volume of alveoli bigger
top of lungs
What is the pressure of pulmonary circulation
low
Where is lung perfusion greater
base
What is daltons law
total pressure of a mixture of gases - sum of their individual partial pressures
What is the ventilation/perfusion ration
rate of alveolar ventilation and pulmonary blood flow
What does the ventilation ratio give an idea about
efficiency of gas exchange in particular regions of the lung
What do ventilation/perfusion mismatches show
problem with gas ventilation or blood perfusion
Describe the structure of adult haemoglobin
tetrameric - 2 alpha chains, 2 beta chains
Describe the haem unit
porphyrin ring containing a single iron atom
What enzyme converts Fe3+ into Fe2+
methaemoglobin reductase
What is the state of iron for haemoglobin to bind
Fe2+
What are the two states of haemoglobin
tensed, relaxed
What state has a low affinity for oxygen
tensed
What state has a high affinity for oxygen
relaxed
what is the state of haemoglobin at low oxygen concentrations
tense
Which way does the oxygen haemoglobin curve shift in acidic conditions
to the right
Which way does the oxygen haemoglobin curve shift when CO2 increases
to the right
Which way does the oxygen haemoglobin curve shift in decrease of pH
to the right
What way does the oxygen haemoglobin curve shift during active respiration
right
What is the effect of temperature increase on the oxygen haemoglobin curve
shifts right
What is the effect of CO2 decrease on oxygen haemoglobin curve
shifts left
What is the effect of 2,3 DPG production increase on oxygen haemoglobin curve
shifts right
What is the effect of shifting the oxygen haemoglobin curve to the RIGHT
decreased affinity for O2 on haemoglobin, more O2 released to tissue
When is the oxygen haemoglobin curve required to shift to the right
active respiration
Describe the structure of fetal haemoglobin
2 alpha, 2 gamma chains
Describe oxygen- haemoglobin curve of fetal haemoglobin
shifts left
What is the effect of shifting the oxygen-haemoglobin curve to the left
higher affinity for oxygen
How does blood carry CO2
bicarbonate, carbonate, carbonic acid, carboamino compounds
How is the majority of CO2 carried
bicarbonate dissolved in the plasma
What is the plasma pH
7.4
