Lecture 4: Control of HR Flashcards
Sympathetic Neurons
short pre gang neuron axons
release ACh along post gang
long postgang axons relaease NE
Parasymp Neurons
long pregang neurons
axons relases Ach
short postgang axons release Ach
Cardiac cycle
events that happen in 1 heartbeat
systole
ejection
diastole
filling
cardiac cycle time
0.8 seconds at rest
heart rate monitored by
changes in ANS
ANS activity can be modified by circulating hormones, higher brain structure
Chronotropic Effects
effects of ANS on heart rate
Cardivascular Center
caudal protions of medulla oblongata
symp neurons that send nerve fibers to heart are here
HR control by Symp Brach of ANS
neourosn of CV center synapse on pregang neurons i
pregang synapse on postgang neurons
post gang send axons to SA and AV and cardiac muscle fibers
Control of HR by Symp Branch of ANS (whats released)
pregang release ACh onto post
post gang NE onto target cells
NE
postgang neurotransmitter for symp NS
Acivates beta1 receptors (widespread effects on cardiac nervous stuff
HR Control mechs
inc rate of depol in SA and AV nodes due to inc in Na contnent
Mech: neurons brought to threshold more frequently
inc in number of APs made per time
CV Center symp and parsymp centers
Fibers from cardiacceleatory: symp
“ “ cardioinhibitory center: parasymp
parasymp from CV center
send axons to heart via vagus nerves
VAGAL MOTORNEURONS
