Respiration Flashcards
where does respiration occur
in the lungs
maintains PH, oxygen, and CO2
Animals must exchange the respiratory gases
O2 and CO2 via passive diffusion
Gas exchange systems are made up of:
Specialized surfaces where gas can move between the body and the environment • Mechanisms that ventilate the environmental side and perfuse the internal side
Faster diffusion–>faster exchange–> possibly better metabolism
Partial pressure
concentration of a gas in a mixture of gasses
Fick’s law of diffusion
applies to all gas exchange of systems
Q=DA(P1-P2)/L)
Q= rate of diffusion
D= diffusion coefficient
A=area across which gases diffuse
P1 and P2= partial pressures of gas at two locations
L=distance btw the locations
(P1-P2)/L: partial pressure gradient
surface area (A) x concentration difference (P1-P2) x membrane permeability (D)/ membrane thickness (L)
what plays a role in membrane permeability
lipid solubility and molecular size
increase in surface area (A)
faster rate of diffusion
increasing concentration difference (P1-P2)
faster rate of diffusion
increasing permeability (D)
faster rate of diffusion
increased membrane thickness
slower rate of diffusion
adaptations to maximize respiratory gas exchange
increase surface area (A)
maximize partial pressure gradients (p1-p2)
(decrease partial pressure in tissues)
minimize diffusion path length (L)
thinner tissues in gills and lungs
maximize diffusion that takes place into and in aqueous medium
circulating blood and active moving of air and water
insects have
spiracles where air diffuses into the body
fish have
gill slits that increase surface area with thin layers
ventilation
breathing
tidal volume
normal amount of air exchanged breathing at rest
expiratory reserve
volume of additional air that can be forcefully exhaled
inspiratory reserve
- additional capacity of the lungs enables deepest breath
residual volume
amount of air left in lungs after maximum exhalation
AIR CAN’T BE EXPELLED FROM LUNGS
will NEVER GO TO 0
Vital Capacity
(VC)= TV+ IRV+ERV
Functional residual volume (FRV)
ERV+RV
Residual volume contributes
to FRV and to dilution of O2 in inhaled air
thoracic cavity
where human lungs are suspended inside this
diaphragm
a sheet of muscle at the
bottom of the cavity.
pleural membrane
covers each lung and
lines the thoracic cavity.
The pleural space contains fluid to help the membranes
slide past each other during breathing.
negative pressure
created in the pleural
space when the
volume of the thoracic
cavity increases.
slight negative
pressure keeps
alveoli inflated, even
in between breaths.
surfactant
reduces the surface tension of a liquid.
gives the surface of a liquid
the properties of an elastic membrane; results from
attraction between water molecules
makes it easier to breathe
allows the inflation of the lungs
one of the last things to develop in newborns
fluid covering inside of the alveoli
has reduced
surface tension that makes the lungs elastic.
Lung surfactant is released by cells in the alveoli when
they are stretched.
It is critical for reducing the work needed to inflate the
lungs.
Premature babies may not have developed the ability to make lung
surfactant; without it, they have great difficulty breathing and may die
from exhaustion and lack of O2.
Treatments include respirators,
hormones to speed lung development, and aerosol surfactants.
2
purpose
All this gas exchange occur in the alveoli
o VERY VERY thin blood vessels and alveoli that allows gas exchange
o Oxygen goes from alveoli to the capillaries to oxygenate red blood cells (RBC)
transport of gases
requires hemoglobin
structure/function of hemoglobin
4 subunits and Heme group
§ 4 places for oxygen to bind
§ 2 places for CO2 to bind
§ When oxygen binds to Hb, CO2 doesn’t like to bind.
§ When CO2 binds to Hb, oxygen doesn’t like to bind.
§ Sigmoidal binding curve
