Final: Respiration 1 Flashcards
physiology
- study of how living animals function
comparative physiology
- comparisons between species to discover physiological and evolutional patterns
environmental physiology
- evolutionary adaptations to the environmental that the animals are found in
evolutionary physiology
- methods of evolutionary biology and systematics using physiology rather than anatomical/molecular markers to understand evolutionary patterns
physiology: link between structure and function (2)
- links between structure and function exist at every level, including protein level
- specific amino acid residues alter protein tertiary and quaternary structure affecting protein or enzyme structure
acclimatization
- adjustment that occurs when an animal moves to another natural environment
acclimation (2)
- adjustment in response to a change in only one environmental variable
- adjustments are short term and reversible
adaptation (3)
- refers to physiological trait that has been selected for over generations and is generally non-reversible
- based upon variability, heritability
- must confer differential survivorship to offspring to be selected for
homeostasis (2)
- the tight regulation of the composition of cellular and intracellular space in most animals, relative to the external environment
- the tendency toward internal stability
negative feedback system (2)
- pathway triggered by deviation in output
- produces changes in output in the opposite direction of the initial deviation
positive feedback system (2)
- pathway triggered by deviation in output
- produces changes in output in the same direction of the initial deviation
what topics does physiology connect/integrate (3)
- genes
- environment
- population
conforming
- system behaviour depends on changes in external environment
how do unicellular and small multicellular organisms participate in gas exchange
- rely on diffusion
why do unicellular and small multicellular organisms rely on diffusion for gas exchange (2)
- these organisms are very small, so there is sufficient surface area to volume ratio
- diffusion oxygen is sufficient to support metabolism
how do larger organisms participate in gas exchange
- rely on combination of bulk flow and diffusion
bulk flow systems (2)
- ventilation
- circulation
bulk flow: ventilation
- moving medium (air or water) over respiratory surface (lung or gill)
bulk flow: circulation
- transport of gases in circulatory system
Fick equation
dQ/dt = D x A x (dC/dx)
Fick equation: dQ/dt
rate of diffusion
Fick equation: D
diffusion coefficient
Fick equation: A
area of membrane
Fick equation: dC/dx
- gradient
dC/dx: gases
- for gases, it is the partial pressure gradient (not concentration) per unit distance
what does the Fick equation tell us about
- the rate of diffusion
Fick equation: O2 transfer
MO2 = K A (PO2a/w - PO2b) / t
Fick equation: MO2
- oxygen consumption/transfer rate
Fick equation: K (2)
- Krogh’s diffusion constant
- diffusion coefficient (D) x solubility
Fick equation; oxygen version: A
- surface area of the barrier that oxygen must cross
Fick equation: PO2a/w
- partial pressure of O2 in air or water
Fick equation: PO2b
- partial pressure of O2 in blood
Fick equation: PO2a/w - PO2b
- partial pressure gradient for O2 between blood and air/blood and water
Fick equation: t
- thickness of barrier
what characteristics of a barrier will maximize the rate of gas diffusion (3)
- high partial pressure gradient
- most possible barrier SA
- thinnest possible barrier thickness
Dalton’s Law of Partial Pressure (2)
- in a gas mixture, each gas exerts its own partial pressure
- the sum of all partial pressures is equal to the total pressure of the mixture
what determines the pressure exerted by a gas (2)
- the number of moles of the gas
- the volume of the chamber
what gases make up air (4)
- nitrogen
- oxygen
- argon
- carbon dioxide
what drives gas diffusion
- partial pressure
Henry’s Law in words
- concentration of gas in liquid is proportional to its partial pressure
Henry’s Law
[G] = Pgas x Sgas
Henry’s Law: [G]
- concentration of the gas (moles/l)
Henry’s Law: Pgas
- partial pressure of the gas (mmHg)
Henry’s Law: Sgas
- solubility of the gas (moles/l/mmHg)
how do gas molecules diffuse into cells
- gas molecules in air must first dissolve in liquid to diffuse into a cell
why will there be higher [O2] in air than water in the same PO2
- solubility of O2 in water is lower than in air
what is the ratio (water:air) of O2 solubility (2)
- 1:30
- for every single oxygen molecule in water, there are 30 in the air
describe the relationship between oxygen partial pressure and concentration in air or water (2)
- concentration of O2 is proportional to partial pressure in air and water
- concentration is always lower in water than in air in the same PO2 due to differences in solubility
what is the ratio (water:air) of CO2 solubility (2)
- ~1
- for every single CO2 molecule in water, there is a single CO2 molecule in the air
compare the CO2 and O2 solubility in water (2)
- CO2 is 30 times more soluble than O2 in water
- large implications for gas exchange
diffusion of gases
- movement of molecules from high partial pressure to a low partial pressure
diffusion rates (2)
- slow over long distances
- fast over short distances
Boyle’s Law (2)
- P1V1 = P2V2
- only applies to gases
Boyle’s Law: P1V1
- initial pressure and volume of gas
Boyle’s Law: P2V2
- final pressure and volume of gas
what is the compressibility of air and water (2)
- air is very compressible
- water is virtually incompressible
why doesn’t Boyle’s Law apply to liquids
- liquids are virtually incompressible
rate of flow equation
Q =△P/R
rate of flow equation: Q
- rate of flow
rate of flow equation: △P
- difference in pressure
rate of flow equation: R
- resistance to flow
how do you increase the rate of flow (2)
- increase the difference in pressure
- decrease the resistance to the flow
how do volume and SA change as radius increases
- as radius increases, volume increases faster than surface area
how do volume and SA change as organisms grow larger
- the ratio of SA to volume decreases
why can’t larger animals rely on diffusion (2)
- limited SA available for diffusion
- increase in the diffusion distance
respiratory strategies: what happens to beating rate of cilia in snail embryos during hypoxia (2)
- cilia on eggs begin to increase beating rate
- increase flow of “new” water to embryos to access more O2, reducing boundary layer limitations
why do boundary layer limitations exist at cell surfaces
- flow rate is reduced due to resistance and friction
Finahow can boundary layer limitations be broken
- increasing flow rate
regulating
- control internal environment irrespective to external environment to an extent
