Conducting System Flashcards
(20 cards)
SA node location
Juction of SVC and RA
Function of SA node
electrical pulses generated + spread through atrial muscle = threshold potential
Pacemaker
Fastest intrinsic depolarisation rate
Blood supply = SA nodal branch of RCA
SA node histology
SA node artery in centre
paler cells
poorly striated cells scattered in fibrous connective tissue
rich autonomic innervation - sympathetic + parasympathetic
Bachmann’s bundle
connects LA and RA
Internodal tracts in RA
anterior/middle/posterior
Cardiac Plexus
between ascending aorta and trachea
Sympathetic innervation
from T1 - T6
cervical + superior thoracic sympathic ganglia
Parasympathetic innervation
carried by vagus
AV node
Interatrial septum - near opening of coronary sinus + septal leaflet of tricuspid valve
Blood supply of AV node
AV nodal artery - branch of RCA
Sympathetic effect on rate
Speed up conduction
Parasympathetic effect on rate
Slow down conduction
AV bundle of His
Across fibrous skeleton
Left bundle branch
Anterior and Posterior fasicles
= Trifascular system
AV bundle location
centre of the interventricular septum
Blood supply of AV artery
LAD - supplies most of interventricular septum + AV bundle
Purkinje fibres R
stimulate the muscle of interventricular septum + wall of RV
- including anterior papillary muscle + moderator band
Purkinje fibres L
stimulate IVS + wall of LV
- including papillary muscles
Location of artificial pacemaker
Pectoral region
- subcutaneous + submuscular
Implantation of artificial pacemaker
access to heart chambers via puncturing subclavian vein or cephalic vein
Under fluroscopy to heart chamber - attatched to endocardium
Left side
