L18- CVRS reflexes Flashcards
what happens in terms of CVS when inspiration occur
increase in VR, right SV and left EDV and SV and HR
decrease in thoraz pressure so air flows in
what is knows when HR increase during inspiration
resp sinus arrthrymia
what nerve supplies diagphragm
phrenic neryve
activity increased during inspiration
2 main mechanims involved increasing HR during inspiration
- central nervous mechanism
- reflex
what happens in central nervous mechanims
during inspiration, central inspiratory drive is stimulated
- increased inhibition of nucleus ambigious > decreases PNS and increase in HR
- increased EPSP to inspiratory motor neurones > increased activit4y if phrenic nerves in diaphrgam
receptor involved in t reflex mechanims of inspiration
- pulm stretch receptors
- slow adapting receptors
mechanism of relfex during inspriation
wall of brochioles and trachea expand
- triggers pulm stretch receptors
- increases inhibition of NA so less vagal activity and increase of HR
inputts that can trigger in inspiration
voluntary hyperventilation ]
-systemic hypoxia and hypercapnia
exercise and mental sgtress
reflexes that can cuase expiration
-triggered by trigeminal receptors
-diving relfex
HR decreased
zones where there are trigeminal nerve endings
opthalamic, mandibular and maxillary
mechanism of diving reflex
decreased inhibtion of NA so vagal activity increase so HR decrease
- trigerminal afferents cause vasocon aand SNS via RVLM
receptors in the facial sinuses and laynx are timulated by what
sinus washing
irritants
intubation
lumps of flood caught
how does mouth to mouth help
expand thorax
- terminates apnoea by triggering pulm stretch Rs
- inhibits vagus nerve
