RS Flashcards
ventilation
exchange between atmosphere and alveoli
gas process
-1st gas exchnage: alveoli and pulmonary capillaries, external respiratoin
-gas transport: pulmonary and systemic circulations between gas exchange locations
-2nd gas exchange: tissue capillaries and IF/tissue cells, internal respiration
how does air pressure gradient work
high to low (ex. breath in is inspiration and goes high atmospheric pressure to low alveolar pressure, opposite for expiration)
Boyle’s law
pressure and volume inverseley related, press
process
-change volume
-change pressure
-create pressure gradient
-produce ventilation
3 pressures
atmospheric, alveolar, intrapleural
atmoshepric pressure
surrounding environemnt
alveolar pressure
in alveoli
intrapleural pressure
between visceral and parietal pleura,
intrapleural pressure mechanigcs
between alveolar and intraplueral: outward pressure to oppose lung elastic recoil (0->-4), lung collapse without
between atmospheric and intrapleural: inward pressure to oppose chest wall elastic recoil (-4 <-0) chest wall spring out without
combininig pressures =lung and cherst wall linked and moving as unit
eupnea
quite unlaboured breathing
mroe forceful breathing
greater increase in lung volume, alveolar pressure higher gradient with amostpheric pressure, recruiting accessory muscles
msucle contractions in breathing (inspiration, opposite for expiration)
-diaphragm: downward flatten
-external intercostals: cheset wall up and outward
-accessory muscles: only duirng more forceful, help intercostals
all opposite for relaxation during expiration
eupnea process (pretty much same for more forceful except additonal muscles and increased pressures)
diaphram/external intercostals - thoracic cavity volume - lung vaolume - alveolar pressure and atmospheric pressure (one bigger than other) - air flow (in or out)
medullary respiratory centre
-pre botzinger complex
-dorsal respiratory group
-ventral respiratory group
in medulla oblongata
prebotzinger complex
possible pacemaker sending signals to dorsal respiratory group
dorsal respiratory group
inspiraotyr neurons
ventral respiratory group
inspiratoyr and expiratory neurons
control centre during eupnea
DRG inspiratory neurons cycle between active and inactive
-durgs like morphine, fent, barbiturates, heroin can surpress DRG neurons
-basci breathing
control centre during more forceful breathing
DRG still working then VRG helps
-VRg neurons activate accessory muscles
pontine respiratory group
in pons, signal DRG for switching between active and inactive for breathing cycle
-strong signal duirng exercse and speaking (and especially swimming)
proprioceptors influence
joints and muscles respond to changes in exercise and one of those changes is signals to the DRG to help match ventilation to movement needs
chemoreceptors influence
peripheral: carotid sinus and aortic arch, arterial blood chnages
central: medulla oblongata to respond to IF changes around brain
need higher altitude change or other changes for these to occur
chemoreceptors: decrease artial O2
increase firing of periopheral chemoreceptors - increase DRG cycling - increase ventilation
chemoreceptors: increased non CO2 (ex. lactate)
increased artial H+ - increasing firing of periopheral chemoreceptors - increase DRG cycling - increase ventilation
chemoreceptors: increased arterial CO2
two ways
1. increased artial H+ - increasing firing of periopheral chemoreceptors - increase DRG cycling - increase ventilation (same as incrased non CO2)
- incrased brain IF CO2 - increase brain IF H+ - increased firing central chemoreceptors - increase DRG cycling - increase ventilation
higher brain centre influences
anything above brainstem taking over breathing, apnea,
risks
1. decrease arterial O2 enough to pass out then involuntary breathing resume
- incrase arterial CO2 and involuntarty breathing start (ex. natural breathing not enough air so you have to get more, like shortness of breath kinda)
