Cardiology - lung function Flashcards
What is the d and what does it do?
D -dorsal respiratory group
inspiratory centre, sets the ‘rate’ for inspiration
what is the V?
expiratory centre
inactive during quiet breathing
inhbits the apenustic centre
What is the A?
A is apneustic centre
stimulated by acitivty in DRG,
inhibitted by pulmonary afferents
What is P?
P is pnemotaxic centre
the ‘inspiratory off switch’
regulates depth and frequency, decided when ‘enough’ of inspiration
Which 2 medualla obloganata inhibte stiumate each other?
How does Pneumotaxic regulate inspiratory?
When AP impluses reaches a thershold activated P centres and cessation of AP
How does Apneustic centre have it affects?
Apneustic helps programme rthym to dorsal centre
What 3 types of nerves innverate the respiratory muscles?
Parasymp
symp
motor
What is function of externalcostal muscles?
internal costal muscles?
external inspiration
internal expiration
What is a singificant feature of capillaries?
Have space between capillaries that are not endo cells -fernatations
How is blood brain barrier different to normal capillaries?
nervous cells that pack endo cells - no leakage
What is the main control of breathing molecules
and why
H+
as it is a product of metabolism
Which only moleucle out of H+, CO2 and HC03- can cross BBB to CSF?
What happens to H+ generated by acidation of C02 in CSF?
Crosses to Medulla and to dorsal respiratory group to determine type of rate and rhythm
Which pulmomary afferents affect ventilation?
irritant receptors
stretch receptors
J-receptors
What do irritant receptors do?
where do you find them?
afferente recepotrs within and benearth airway epithelium
leads to coughing, forceful expiration against a closed glottis
then with sudden glottal opening and high veloclity explusion of air
What do strech receptors do?
pulmonary activated when excessive inflation of lungs
stimulate VRG and pneumotaxic
inhibit DRG and apneustic centre
inspiration inhbited and expiration stimulated
What do J receptors do?
sensitive to oedma and pulmonary capillary engorgement
increases breathing freq
What happens to level of 02 and CO2
before holding breathe
during
and after?
What physiologically happens in medulla when you hold your breathe?
C02 increase + H+ accumlate in BBB
stimulate medulla to breathe in.
What does
alkalosis
acidosis
mean?
alkalosis - circumstances decrease H+
acidosis - circumstances incraese H+
What are the 2 types of distrubances to fix acid base homeostatis?
ventilatiory - fast
metabolic - slow
How does ventilation alter pH?
rapid compensatory reponse to change C02 removal
How does metabolic alter pH?
changes in HC03- and H+ secretions in kidney can slow/ DAYS
compenstoary response to pH
Where are peripheral chemoreceptors found?
near carotid barorecpetors
at bification of carotid arteries in structures called arotic bodies and carotic bodies
Why is chemorecepors positoned where they are?
monitoring the blood going to the brain
How is breathing innerates by exercise?
-efferent from PMC to skeletal muscles partly innvervate medulla
AND
-propiocetive afferents from muscle spindles and golgi tendon innervate medulla on way to brain
TO BREATHE AS INCREASE ENERGY REQUIRMENT
effects of skin on breathing?
temperature nerves
cold water- leads to ventilatory and inspiratory gasps
