Pulmonary Flashcards
Pressure volume relationship
Increase Volume = dec pressure to all more gas in
Gases in system
gases spread vs fluids don’t oocupy entire space
Both flow from HIGH TO LOW GRADIENTS
F-FLOW= DELTA (CHANGE) PRESSURE/R-Resistance
Pressures w/ resistance
INc. resistance= less flow
Respiration
breathing But truly EXCHANGE OF GASES Pulmonary ventilation External respiration (gas) Gas transport Internal respiration
Thorax volume
ideal cylinder all around
Dome shaped floor
Diaphragm contracts to flaten and inc space and volume
INc volume= low pressure, since gases flow HIGH TO LOW (gradients etc.)
Contracts-External (High pressure gas) enter to Low pressure areah.
Relaxes- Dome shaped, force air out d/t HIGH pressure
Movements on thorax V-P
Diaphram contracts floor flattens
A/P elevation of ribs-
Accessory muscles: Pec minor, serratus (lateral, A/P)
these DONT act directly on the lungs
Lung anatomy
R 3 lobe
L 2 lobes
floats/attached to mediastinum (central space in thorax Mediastimum
Middle chest
Heart sits inferior to hilum
Pleura surrounds
Pleura space- may conatain air or fluid, potenial space
Lungs push down in expansion, so two layers membrane formed
Transpulmonary pressure
alveolar pressure minus the pleural pressure,
recoil pressure-pressure tending to collapse the lungs.
grows when tthe 2 are too far apart,
As Ppl gets less, O2 pressure inc is enough, then we expire collapse lung.
Never negative
DEC IIN OBST DZ- d/t obstruction causing inc. airway resistance work, thus alveolar pressure dec.
Pleural Pressure
Negative all the time-Favors expansion for fluid in pleura space=Fluid hydrogen bonds the pleural membranes together, sticks. visceral and parietal stick together
As the lungs expand, bc of the stickyness, the parietal membrane takes the lungs with the thorax
Pressure drops w/ inspiration, More negative with expansion.
Alveolar Pressure
pressure within the alveoli of the lungs and it’s the balancer alveoli and atmosphere.
zero point- alveolar pressure equals atmospheric
subtraction of alveolar from atmospheric pressure determines airflow.
Compliance
measure the amount of expansion
for change in transpulmonary pressure.
EX- volume expands by 1 liter for 1 millimeter of change, that’s the compliance.
determined by its elasticity.
Change in volume for any give change in pressure
Obst dz= meausre lung rise and recoil
Lung elasticity
changes with age, fibrois, scar
compliance
Surface tension of alveoli cause elasticity- air water interface (droplet bc H-bonds pulling toward each other
surface tension pull the alveoli closed and could collapse the lung. caused by H- bonds
Alveoli cells produce this to stay open to reduce surface tension. Breaks surface tension, gets in btwn H-bonds to lessen pull towards each other, like a soap.
Surfactant
Compliance work
energy expended to expand lungs agaisnt it own elasticity
Large work, large input of energy, healthy (imagine sick, tht why tired, asthma, etc)
3-5% of energy expended quiet breath, expanding against own elasticity
Inc. in Restrictive DZ, fibrosis
Tissue resistance work
Energy expended to overcome viscosity/thick lungs
Lungs thick heavy- fluid filled, but spongy
Sick- require lot of energy to breath, thus skinny
Fibrosis
Inc in REstrictive DZ, fibrosis
