PHYS20008 Lecture Notes - Lecture 21: Pulmonary Edema, Extracellular Fluid, Pulmonary Vein
12 Jun 2018
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Department
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Professor
Lecture 21
PHYS20008 - HUMAN PHYSIOLOGY
LECTURE 21
GAS EXCHANGE AND TRANSPORT
ALVEOLAR
STRUCTURE
•Law of laPlace
says that
smaller ones
easier to inflate
than larger
ones.
•Alveoli are
surrounded by
elastic fibres &
capillaries.
•In pink is the
capillaries with
extremely tight
junctions.
These include
interstitial fluid
on the outside;
this is where
gas exchange
happens.
EXCHANGE SURFACE OF
ALVEOLI
•Entire distance between wall of
capillary is this layer of interstitial
fluid.
•Pulmonary oedema = interstitial
fluid gets thicker.
•It is important that the layer is thin
in
order for gas exchange. Thicker membrane = lower rate
of diffusion.
•Q. Well oxygenated blood is carried by which blood vessel?
•A. Aorta & pulmonary vein.
Document Summary
Structure: law of laplace says that smaller ones easier to inflate than larger ones, alveoli are surrounded by elastic fibres & capillaries, in pink is the capillaries with extremely tight junctions. These include interstitial fluid on the outside; this is where gas exchange happens. Alveoli: entire distance between wall of capillary is this layer of interstitial fluid, pulmonary oedema = interstitial fluid gets thicker, it is important that the layer is thin order for gas exchange. Thicker membrane = lower rate of diffusion. in: q. Well oxygenated blood is carried by which blood vessel: a. Doesn"t need to be high because the circuit is quite short so we don"t need much pressure in order to overcome the resistance of the system. Matching: local control mechanisms attempt to match ventilation and perfusion, alveoli in lungs aren"t always getting deeply ventilated; due to posture or structural changes etc.
