overview Flashcards
what does internal resp refer to
intracellular mechanisms which consumes 02 and produces co2
external resp
lead to the exchange of 02 and co2 between the external environment and cells of the body
four steps of external resperation
ventilation
gas exchange between alveoli and blood
gas transport in the blood
gas exchange at the tissue leve
ventilation
mechanical process of moving gas in and out of the lungs
gas exchange between alveoli and blood
The exchange of O2 and CO2 between the air in the alveoli and the blood in the pulmonary capillaries
gas transport in the blood
The binding and transport of of O2 and CO2 in the circulating blood
gas exchange at the tissue leve
The exchange of O2 and CO2 between the blood in the systemic capillaries and the body cells
what type of process is normal resting expiration
passive
what type of process is inspiration
active
how do the lungs ahdere to the chest wall and follow its movement
The intrapleural fluid cohesiveness
Transmural pressure gradient
Intrapleural fluid cohesiveness
water moleucles in intrapleural flluid are attracted to each other and resist being pulled apart hence pleural memrbanes tend to stick together
transmural pressure gardient
the difference between intrathoracic (or ‘intrapleural’) and alveolar pressure.
intra alveolar pressure- intrapulmonary
pressure within lung alveoli
intrapleural pressure – intrathoracic
pressure exerted outside the lungs within pleural cavity , usually less than atmospehric
pressures across lung wall
intraalveolar pushes outward
intrapleural pushes inward
stretching lungs to fill the larger thoracic cavity
transmural pressure gradient pushes out on lungs
pressures across thoracic wall
atmospheric inward
intrapleural outward
compresses thoracic wall
transmural pressure gradient pushes inward on the lungs
what abolishes the pressure gradient
pneumothorax
what pressure does a pnuemothoax raise
intrathoracic
boyles law
At any constant temperature the
pressure exerted by a gas varies
inversely with the volume of the gas
what happens to the pressure exrted by gas as volume of it increases
as the volume of a gas increases the pressure exerted by the gas decreases
intra alveolar pressure assoc with atmoshperic during inspiration
must become less for air to flow in as air flows to a region of high to low
what makes the intra alveolar pressure fall
expansion of the lungs
what happens to the diaphragm on inspiration
descends
which muscles are used upon inspiration
external intercostals
alveolar surface tension
atttraction between water moolecules at liquid air interface
what reduces alveolar surface tension
surfactant
surfactan
complex mixture of lipids and proteins
what is surfactant secreted by
type 2 alveoli
beenift of surfactant
preven thte smaller alveoli from collapsing and emptying their contents into larger alveoli
