Respiration
Introduction
• Exchange of respiratory gases is vital for survival
• Animals die:
- Minutes without oxygen
- Days without nutrients
- This shows the importance of oxygen and respiration.
• Oxygen is important in terms of production of ATP.
• Removal of carbon dioxide is vital as its accumulation can lead to respiratory acidosis.
• Ventilation is influenced and regulated by chemoreceptors (a sensory cell or organ responsive [responds quickly] to
chemical stimuli) for: Pa (partial pressure) CO2, O2 and Ph located in the brain stem, aortic and carotid bodies as well
as by neural impulses from lung stretch receptors and impulses from cerebral cortex.
• Headaches, confusion, feeling tired, tremors (involuntary movement), sleepiness, flapping tremor and dysfunctional
of the cerebrum of the brain which may progress to coma if there is no intervention.
• Acidosis affects respiration
- respiratory system
Hyperventilation
shift of oxyheamoglobin to left
- cardiovascular system
sympathetic over activity
tachycardia (excessive HR)
vasoconstriction
- CNS
poisoned and then decompressed
Introduction to oxygen and carbon dioxide
• Animals use different strategies to take in oxygen from the environment
• Oxygen is vital in metabolic processes
• Oxygen is the final electron acceptor
• No oxygen= no ATP= no energy requiring process will take place in a cell
• Production of ATP is dependent on electron transport through electron transport chain.
- This process produces large amount of ATP, which is a major carrier around the body
• Fan worm strategy for obtaining oxygen:
- Once the tentacles are unfolded and released back out into the medium of the sea it produces a large SA of a gas
exchange membrane over which there is a continuous flow of medium (seawater) containing oxygen, which can
then be taken up by the exchange membrane by the process of diffusion.
- At times of danger, oxygen is limited inside the tube into which the tentacles withdraw as once the oxygen in the
surrounding medium (sea water) within the tube has been taken up by diffusion into the animal it cannot be
replenished.
Why is gas transport vital?
• Lack of oxygen
- Effects on ATP production
- Insufficient ATP damages processes that require energy, such as disrupting the membrane where ion pass
through
• Build-up of carbon dioxide
- Acidosis (acidic blood supply), which can affect the following :
1. Respiratory system
chemoreceptors pCO2, pO2 and pH
Hyperventilation to obtain more oxygen
, 2. Cardiovascular system
-sympathetic over activity leads to tachycardia (excessive HR)
vasoconstriction
3. CNS
cerebral vasodilation
depression (reduce level of strength or activity) of CNS
Movement (mechanism) of respiratory gases
1. Simple diffusion
2. Convection (bulk flow)
NO ACTIVE TRANSPORT OF OXYGEN
Simple diffusion
• Chemical potential
- is the ability to change (change chemically or physically) in this context it is the change in concentration of
molecules
• Diffusion
- is from an area of high to low concentration or chemical potential till equilibrate
• Rate of diffusion is proportional α difference in concentration
- The higher the concentration differences the faster the rate of diffusion
- simple when considering diffusion between mixtures of liquids or gases more complicated when considering
movement between gases and liquids
• Diffusion between gas mixtures and aqueous solution.
-not concentration
-partial pressure (amount of gas)
Partial pressure (pp): gas phase (john dalton)
• The law of partial pressures
- Hypothetical total pressure exerted by a mixture of gases is the sum of individual pressure of each component
gas in the mixture
• fundamental law in pp:
- PP of any gas is independent of any other gas in the mixture
• Each component of gas behaves in terms of its pp as if it alone occupied the entire volume
• Thus pp of each gas can be calculated
Universal gas law
PV=nRT
Or
P = (n/V)RT
• P=pressure
• V=volume
• N=number of moles of gas
• R=universal
• T=absolute temperature
• In a gas mixture, pp=number of molecule=concentration
• n/V=concentration (i.e. no of moles in a volume)
,Law of partial pressure: chemical potential of gases
• total pressure = sum of individual pressures
• proportional of gases in a mixture
-mole fractional concentration or volume fractional concentration for each gas in mixture.
• air exerts a pressure of 1 atmosphere
• F=mole or volume fractional concentration
• Px=FxPtot
• PP =fractional concentration x total pressure of gas mixture
• If removed 1 gas pp the rest remain the same
Partial Pressure: aqueous phase
• Partial pressure of a gas dissolved in aqueous solution
- Pp of a gas in a gas phase with which the solution is at equilibrium
• Gases collide with surface and dissolve
• Equablibrium is reached whereby gas dissolving = gas escaping
• Increasing pressure increase gas molecules per unit volume
• More collisions with surface increase in dissolved gas-new equilibrium
• Pp in AQ phase=pp of gas in atmoshphere
Too simplistic-depends upon the nature of the liquid and the gas
1. Reach equilibrium; pp in solution and air will be equal
2. Increase pp of atmosphere it will re-equilibrate of gas
, Gases in aqueous solution
• Tension
- Term of pp of gases in Aq solution
- When discussing pp in gases might see it described as tension-same thing
• Henry’s Law
- In gas
Pp proportional concentration
- In Aq
More complex
Depends upon the nature of the solution
Gases dissolving in liquid by becoming distributed in water molecules like any solute i.e. glucose
Henrys law relates pp to conc in liquids
Important characteristic of gases dissolved in Aq solution
• Pp of a gas in an Aq solution depends upon:
- Solubility
Temperature
Salanity
• Gas solubility
- Gas solubility is defined by its absorption coefficient
- Dissolved concentration depends upon A
- A is the difference in different gases
- Concentration=pp but depends on coefficient
- The higher the solubility coefficient the more the gas is soluble in Aq solution.
- Absorption coefficient, henry’s law
- Dissolved concentration of gas when partial pressure of gas in solution is 1atm is dependent upon A
- Cx=APx
- Solubility of different gases is different
- Solubility coefficient, A of CO2>O2 & N
- Thus in 1L of water at 0⁰C at 1 atm
77 mmol/L CO2
2.2mmol/L O2
1.1mmol/L N
• Solubility is also dependent upon the nature of the liquid i.e. its temperature and salinity
• Need to take in account other factors, which include temp and salinity
• As temp increases, solubility decreases-comes out of solution and see bubbles form
- Leaving a glass of water overnight causes the water molecules to equilibrate to ambient temp and release gas
• Increasing salinity decreases solubility
- Salinity, if increase salt concentration in water will reduce solubility of gas in water
- Salinity is vital for marine animals. Less gas available for water animals than air breathing animals.
Introduction
• Exchange of respiratory gases is vital for survival
• Animals die:
- Minutes without oxygen
- Days without nutrients
- This shows the importance of oxygen and respiration.
• Oxygen is important in terms of production of ATP.
• Removal of carbon dioxide is vital as its accumulation can lead to respiratory acidosis.
• Ventilation is influenced and regulated by chemoreceptors (a sensory cell or organ responsive [responds quickly] to
chemical stimuli) for: Pa (partial pressure) CO2, O2 and Ph located in the brain stem, aortic and carotid bodies as well
as by neural impulses from lung stretch receptors and impulses from cerebral cortex.
• Headaches, confusion, feeling tired, tremors (involuntary movement), sleepiness, flapping tremor and dysfunctional
of the cerebrum of the brain which may progress to coma if there is no intervention.
• Acidosis affects respiration
- respiratory system
Hyperventilation
shift of oxyheamoglobin to left
- cardiovascular system
sympathetic over activity
tachycardia (excessive HR)
vasoconstriction
- CNS
poisoned and then decompressed
Introduction to oxygen and carbon dioxide
• Animals use different strategies to take in oxygen from the environment
• Oxygen is vital in metabolic processes
• Oxygen is the final electron acceptor
• No oxygen= no ATP= no energy requiring process will take place in a cell
• Production of ATP is dependent on electron transport through electron transport chain.
- This process produces large amount of ATP, which is a major carrier around the body
• Fan worm strategy for obtaining oxygen:
- Once the tentacles are unfolded and released back out into the medium of the sea it produces a large SA of a gas
exchange membrane over which there is a continuous flow of medium (seawater) containing oxygen, which can
then be taken up by the exchange membrane by the process of diffusion.
- At times of danger, oxygen is limited inside the tube into which the tentacles withdraw as once the oxygen in the
surrounding medium (sea water) within the tube has been taken up by diffusion into the animal it cannot be
replenished.
Why is gas transport vital?
• Lack of oxygen
- Effects on ATP production
- Insufficient ATP damages processes that require energy, such as disrupting the membrane where ion pass
through
• Build-up of carbon dioxide
- Acidosis (acidic blood supply), which can affect the following :
1. Respiratory system
chemoreceptors pCO2, pO2 and pH
Hyperventilation to obtain more oxygen
, 2. Cardiovascular system
-sympathetic over activity leads to tachycardia (excessive HR)
vasoconstriction
3. CNS
cerebral vasodilation
depression (reduce level of strength or activity) of CNS
Movement (mechanism) of respiratory gases
1. Simple diffusion
2. Convection (bulk flow)
NO ACTIVE TRANSPORT OF OXYGEN
Simple diffusion
• Chemical potential
- is the ability to change (change chemically or physically) in this context it is the change in concentration of
molecules
• Diffusion
- is from an area of high to low concentration or chemical potential till equilibrate
• Rate of diffusion is proportional α difference in concentration
- The higher the concentration differences the faster the rate of diffusion
- simple when considering diffusion between mixtures of liquids or gases more complicated when considering
movement between gases and liquids
• Diffusion between gas mixtures and aqueous solution.
-not concentration
-partial pressure (amount of gas)
Partial pressure (pp): gas phase (john dalton)
• The law of partial pressures
- Hypothetical total pressure exerted by a mixture of gases is the sum of individual pressure of each component
gas in the mixture
• fundamental law in pp:
- PP of any gas is independent of any other gas in the mixture
• Each component of gas behaves in terms of its pp as if it alone occupied the entire volume
• Thus pp of each gas can be calculated
Universal gas law
PV=nRT
Or
P = (n/V)RT
• P=pressure
• V=volume
• N=number of moles of gas
• R=universal
• T=absolute temperature
• In a gas mixture, pp=number of molecule=concentration
• n/V=concentration (i.e. no of moles in a volume)
,Law of partial pressure: chemical potential of gases
• total pressure = sum of individual pressures
• proportional of gases in a mixture
-mole fractional concentration or volume fractional concentration for each gas in mixture.
• air exerts a pressure of 1 atmosphere
• F=mole or volume fractional concentration
• Px=FxPtot
• PP =fractional concentration x total pressure of gas mixture
• If removed 1 gas pp the rest remain the same
Partial Pressure: aqueous phase
• Partial pressure of a gas dissolved in aqueous solution
- Pp of a gas in a gas phase with which the solution is at equilibrium
• Gases collide with surface and dissolve
• Equablibrium is reached whereby gas dissolving = gas escaping
• Increasing pressure increase gas molecules per unit volume
• More collisions with surface increase in dissolved gas-new equilibrium
• Pp in AQ phase=pp of gas in atmoshphere
Too simplistic-depends upon the nature of the liquid and the gas
1. Reach equilibrium; pp in solution and air will be equal
2. Increase pp of atmosphere it will re-equilibrate of gas
, Gases in aqueous solution
• Tension
- Term of pp of gases in Aq solution
- When discussing pp in gases might see it described as tension-same thing
• Henry’s Law
- In gas
Pp proportional concentration
- In Aq
More complex
Depends upon the nature of the solution
Gases dissolving in liquid by becoming distributed in water molecules like any solute i.e. glucose
Henrys law relates pp to conc in liquids
Important characteristic of gases dissolved in Aq solution
• Pp of a gas in an Aq solution depends upon:
- Solubility
Temperature
Salanity
• Gas solubility
- Gas solubility is defined by its absorption coefficient
- Dissolved concentration depends upon A
- A is the difference in different gases
- Concentration=pp but depends on coefficient
- The higher the solubility coefficient the more the gas is soluble in Aq solution.
- Absorption coefficient, henry’s law
- Dissolved concentration of gas when partial pressure of gas in solution is 1atm is dependent upon A
- Cx=APx
- Solubility of different gases is different
- Solubility coefficient, A of CO2>O2 & N
- Thus in 1L of water at 0⁰C at 1 atm
77 mmol/L CO2
2.2mmol/L O2
1.1mmol/L N
• Solubility is also dependent upon the nature of the liquid i.e. its temperature and salinity
• Need to take in account other factors, which include temp and salinity
• As temp increases, solubility decreases-comes out of solution and see bubbles form
- Leaving a glass of water overnight causes the water molecules to equilibrate to ambient temp and release gas
• Increasing salinity decreases solubility
- Salinity, if increase salt concentration in water will reduce solubility of gas in water
- Salinity is vital for marine animals. Less gas available for water animals than air breathing animals.
