coronary circulation and conduction system Flashcards
is cardiac muscle striated?
yes
what is the name of the joining region between individual muscle cells?
intercalated discs
what is chronotropy?
the ability to generate electrical signall
what is dromotopy?
conduction
what is bathmotropy?
excitability/ability to respond
what is Isotropy?
contractility (the actual response)
what is lusitropy?
relaxation
which cusp of the valve of the aorta is the NON-CORONARY cusp?
the posterior cusp
during systole or diastole do the coronary arteries receive blood?
diastole
where does the right coronary artery pass between once it emerges from the right coronary cusp?
between the right auricle and pulmonary trunk
what is the first branch the RIGHT coronary artery gives off?
the SA nodal branch
what branches does the right coronary artery give off to supply the right atrium?
atrial branches
what branch does the right coronary artery die off before it turns onto the posterior surface?
right marginal branch
what branch of the right coronary artery anastomoses with branches of the left coronary artery in the coronary sulcus and at the apex?
the posterior inter ventricular branch
is the left coronary artery or the right coronary artery usually dominant?
RCA
what is obstruction of the right coronary artery usually refereed to as?
inferior infarct
what is obstruction of the right coronary artery likely to cause?
arrhythmias
which coronary artery is shorter but thicker?
the left coronary artery
what does the left coronary artery divide into after it has travelled in the coronary sulcus?
the circumflex and anterior inter ventricular
what groove does the anterior iterventruclar branch of the LAD travel in?
the anterior inter ventricular groove
what does the anterior inter ventricular branch of the LAD anastomose with at the apex?
the posterior inter ventricular branch of the RCA
which branch of the LAD is most commonly affected by atherosclerosis?
the anterior inter ventricular branch
what branch does the circumflex branch of the LCA give off?
the left marginal branch
what does the circumflex branch anastomose with in the coronary sulcus posteriorly?
branches of the RCA
what does obstruction of the left anterior descending artery cause?
anterior infarct
what does obstruction of the circumflex coronary artery cause?
lateral infarct
what does left anterior infarct cause?
loss of LV function, which causes ventricular fibrillation
what supplies the part of the interventriclar septum containing the bundle of His?
the right coronary artery
how is dominance controlled in terms of coronary arteries?
whichever coronary artery supplies the AV node is dominant
which artery is the most commonly affected by atherosclerosis?
anterior interventriclar branch
what vessels are commonly used for coronary artery bypass grafting (CABG)?
left internal thoracic
great saphenous vein (must be inserted upside down because of valves)
what are the three main veins on the anterior surface of the heart?
the great cardiac vein (accompanies LAD)
the small cardiac vein (accompanies right marginal branch)
the anterior cardiac vein
where do the anterior cardiac veins drain into?
they drain INDEPENDENTLY into the right atrium
what is the main vein on the posterior surface of the heart?
the middle cardiac vein
where does the coronary sinus lie?
lies between the LA and LV
what are the FOUR components of the conduction system of the heart?
the SA node
AV node
bundle of his
purkinje fibres
what is another name for the Keith-flack and pacemaker node?
the SA node
where is the SA node located?
anterior to the opening of the SVC, at the upper end of the cristae terminalis
what is the depolarisation rate of the SA node?
70-80 beats per minute
what is another name for the Aschoff-Tamara node?
the AV node
where is the AV node located?
at the poster-inferior part of the IA septum close to the opening if the coronary sinus
what is the depolarisation rate of the AV node?
40-55 bpms
where does the bundle of His begin?
at the AV node
what is the course of the bundle of his?
starts at AV node
descends in the membranous part of IV septum, into the muscular part, then splits into the purkinje fibres which spread out into the ventricular walls
what is the depolarisation rate of the bundle of his?
25-40bpm
what is the effect of the sympathetic innervation on the coronary arteries?
they are dilated
what spinal nerves do the sympathetic fibres travel in?
T1-5/6
what is the effect of the parasympathetic innervation on the coronary arteries?
constrict coronary arteries
how is it defined whether the cardiac plexus is superficial or deep?
if it is anterior or posterior to the pulmonary trunk
what is the location of the cardiac plexus?
inferior to the aortic arch, adjacent to the bifurcation of both the pulmonary trunk and the trachea
