Flashcards
Gas Exchange IV - Mechanism of Ventilation 3
Cards in this deck (43)
- 1Where do the pleural membranes of the lung meet?At the hilum of the lung
- 2What is the pressure within this closed pleural space w.r.t atmospheric pressure?Pressure is negative
- 3How does the Pulmonary Circulation run w.r.t the Systemic Circulation?Pulmonary Circulation runs in series with the Systemic Circulation
- 4Describe Pulmonary CirculationPulmonary circulation:
RV-> LUNGS -> LA
from right ventricle to lungs via pulmonary arteries
From lungs to left atrium of the heart via pulmonary vein - 5Describe Systemic CirculationLV->BODY->RA
Blood flows from left ventricle to cells of body via systemic arteries
Flows from body to right artery of the heart via systemic veins - 6What is the pressure like in Pulmonary Circulation? What does this facilitate?Pressure in Pulmonary Circulation are very low
Slow flow rate allows efficient Mx - 7How do the Pulmonary arteries assist in Mx?Pulmonary arterial walls are thin
Pulmonary vascular resistance is low
(R squeezes out material from blood, a sponge that's not being wrung will just soak) - 8Show an equation that allows us to formulate Vascular Resistance(InP - OutP)/Blood Flow
- 9How does gravity influence ventilation and perfusion in humans?At rest, bottom of lung is rich in blood and oxygen
Perfusion and ventilation decreases as you go towards top of the lung - 10How do alveoli differ depending on the region of the lung?Alveoli at bottom of lung expand less than those at top
- 11What is VA?Alveolar ventilation rate, volume of fresh air available for Gx per minute
- 12What is Q?Rate of blood flow/volume of blood available passing through Pulmonary Circulation
- 13Why does regional VA:Q vary across the lung?At bottom of lung BF/AF at top AF/BF
Top part of lung much higher AF/BF, not really participating in gas exchange - 14Why is regional mapping necessary?Blood flow 3x faster than ventilation, also changes in BF/lung ventilation depending on area
- 15How does regional VA:Q vary?Regional VA:Q can vary from 0 to infinty
- 16What occurs at 0?No ventilation, no gas exchange
Blood crosses lung without coming into contact with alveolar air (right to left shunt) - 17What happens at infinity?Anatomical dead space, or ventilated alveoli that are not perfused
- 18Why is local matching important?Local matching of ventilation and perfusion is important to optimise Gx in the lungs
The ratio is kept near 1:1 on the local scale - 19What is modulated for VA:Q matching?Blood flow
- 20What effect does low PO2 have on blood flow?Vasoconstriction occurs as a result of hypoxia
Blood is directed away from poorly-ventilated areas
The response is very non-linear - 21How does vasoconstriction halt blood flow?Resistance increases prevents blood from flowing to that part of the lung
- 22Why is blood flow restricted from accessing these areas of the lung?These areas aren't ventilated, so gas exchange can't occur well and the blood would just shunt through
- 23How do fish maximise Gx?Countercurrent flow
- 24How do bird lungs maximise Gx?Bird lungs have continous airflow over the respiratory interface
Air capillaries and blood capillaries are adjacent so fresh air continuously flows over the gas exchange surface - 25Show the efficacy of Gx of fish mammals and birdsmammals
- 26Diagram of alveolusbam
- 27Describe movement of air through an alveolusDissolve in liquid layer lining the alveolus
Alveolar wall -> IS Space -> BC -> Plasma - 28How is transfer of O2 further influenced?Influenced by diffusion across the RBC membrane
Combines with haemoglobin
(diagram) - 29How fast is this transfer of O2?Very fast
- 30What is Hb?Four polypeptide subunit
haem group at the centre - 31Describe Hb-O2 dissociation curveSigmoidal (S) curve
Initially pp O2 increases and O2 binds to first haem group
Once 1 O2 is bound to Hb co-operative binding occurs
Easier for next O2 to bind, increased O2 affinity - 32What is meant by deoxygenated blood?Not fully complexed with oxygen
- 33Describe the Bohr ShiftIncrease in PCO2 causes a shift to the right of the curve
Increase in PCO2 signifies an increase in respiration
increased metabolic demand
Lowers affinity of Hb towards O2
causes a dissociation - 34What other factors also cause an increase in O2 dissociation? (3)Increased H+
Increased temperature
Increased 2-3BPG - 35Name 3 respiratory pigments and their characteristicsHaemoglobin 4 Fe-containing haem groups
Myoglobin - similar to single Hb subunit
Haemocyanin - Cu containing molecule, packaged in cells "blue blood" - 36How does myoglobin function as an O2 reserve?Myoglobin has a very high affinity for O2, doesn't dissociate easily
- 37What is meant by P50 on an oxygen dissociation curve?'Environmental' PO2 at which Hb is 50% saturated
- 38How does foetal Hb differ from maternal Hb?Higher O2 affinity, so can collect O2 from maternal Hb
- 39Why is this important?Lungs of foetus not functional
Needs O2 supply - 40Draw a diagram showing O2 and CO2 exchange with the circulatory system and tissues of the bodyblahblah blah
- 41carbonic anhydraseblah
- 42How do CO2 levels alter pH of the cell?Can form carbamino compounds on Hb, this is prevalent in the venus side of circulation
- 43Haldone effectH+ +HbO2 -> H+ + Hb + O2
Information
- Description
- User has deleted their subject information Flashcards on Gas Exchange IV - Mechanism of Ventilation 3, created by Deleted user on 19/04/2018.
- Created by
- Deleted user · Apr 2018
- Updated
- Apr 19, 2018
- Views
- 8
- History
-
- Created by J yadonknow · Dec 27, 2017
- Copied by J yadonknow · Apr 19, 2018
- Rating