Coronary Circulation & innervation of the heart Flashcards
what groove encircles the heart and separates the atria and ventricles?
atrioventricular groove
what are the components that form the interventricular groove?
anterior and posterior
where do arteries of the heart lie? what does it enable to do?
• Arteries lie on the external surface of the heart along the grooves which also enables to separate the chambers
what are the main arteries of the heart?
right/left coronary a
Where does the R coronary A travel?
Travels within the atrioventricular valve on the right side of the heart
what branches generally arise from the RCA?
marginal A
posterior interventricular A
sinoatrial nodal A
What A. travels along the margin of the right ventricle
marginal A
how does the posterior interventricular A travel?
curls around the back and dives 90 degrees into the interventricular groove (posterior)
Where does the L coronary A travel?
Travels within the atrioventricular groove on the left side of the heart
what branches does the LCA give rise to?
anterior ventricular A
circumflex A
where does the anterior ventricular A travel?
travels within the interventricular groove
relative to the heart, how is the circumflex A positioned?
it wraps around the back and does down to travel in the atrioventricular groove to the posterior surface of the heart
where do the main A. of the heart originate from?
ascending aorta
where do the main A. of the heart branch off of?
• They branch directly on the openings of the aortic valves found within the aortic sinuses
what acts as a valve to open and close the orifice of the coronary A?
cusps of the aortic valve
what happens when the aortic valve is open?
the coronary opening is closed
what are the different types of vascular variations of the heart?
- right dominant equal
- right dominant unequal
- left dominant unequal
- single coronary supply
which dominancy is seen is the majority of the population
right dominance
equal
how is vascular dominancy defined?
defined by which main coronary A gives rise to the posterior interventricular A
during right dominant unequal vascularity, which side supplies the majority of the blood?
right side
what is a coronary bypass used for?
Treatment for blockage of coronary A.
what procedure can be used during coronary bypass?
venous or arterial grafts
what does a venous graft involve?
o Venous grafts involve taking a vein and bypassing blocked A by grafting it directly to the aorta
what vein is generally taken for bypass surgery?
greater saphenous vein from ankle
what are some disadvantages of venous grafts?
grafted above the valves causes for the vein to be under constant hight pressures thus more prone to damage
what A. are generally used for Arterial grafts?
internal thoracic A
radial A from anatomical snuff box
why can the internal thoracic A be used for grafts?
because the thoracic wall is completed anastomosed by the anterior and posterior vessels hence its removal will not block circulation
which method of grafting is preferred? why?
Arterial
more rigid than veins
what are the 3 main veins responsible of the venous drainage of the heart?
- greater
- middle
- small cardiac veins
where does the Great cardiac vein travel? with what A?
travels in the anterior interventricular groove along with the anterior interventricular A.
where does the middle cardiac vein travel? with what A?
travels in the posterior interventricular groove with the posterior interventricular A
where does the small cardiac vein travel? with what A?
travels along the margin of the right ventricle with the marginal A.
what do the cardiac veins drain into?
coronary sinus
where is the coronary sinus found?
on the posterior surface of the heart in the atrioventricular groove
into what is the blood from the coronary sinus emptied into?
in the RA
what are the components of the aorta?
ascending
descending
arch
what does the aorta loop around?
the left pulmonary A, V & the left primary bronchus
what does the descending aorta travel along?
posterior to the the left pulmonary A, V & the left primary bronchus
what branches arise from the branch of the aorta?
Brachiocephalic trunk A
Left common carotid A.
Left subclavian A
what are the branches of the brachiocephalic trunk?
Right Subclavian A
Right common carotid A
what forms the SVC
formed by the convergence both brachiocephalic veins which are formed on either side by the convergence of the
Subclavian V
Internal jugular V
what vein drains blood from the UL?
subclavian
what vein drains blood from the head and neck?
Internal jugular V
where is the SA node located
in the atria, generally in RA
what is the SA more prone to when located in the LA?
pinching due to its location behind the aorta
what happens when the SA is stimulated?
atrial contraction
what allows the SA node to travel and stimulate the AV node?
internodal branch
what does the AV node pass its stimulus to via what?
muscles of the ventricles via the bundle of HIS
where is the bundle of HIS located?
interventricular septum
what does the bundle of his split into?
right/left bundle branches
where do the right/left bundle branches go to?
they descend through the interventricular spetum and give branches to the walls and the papillary muscles of the ventricles
what is the name of the branches that the right/left bundle branches give out to?
purkinje fibers
what type of innervation does the heart receive?
ANS
what type of innervation causes for increased heart rate?
sympathetic
what spinal segments are involved if the heart receive sympathetic innervation?
T2-T4
what forms the thoracic cardiacnerves
Information that exits the paravertebral ganglia of the sympathetic chain
what gives rise to the cervical cardiac nerves
Some information ascends through the sympathetic chain to the cervical ganglia (superior, middle, inferior)
what NS causes for a decreased HR?
parasympathetic NS
what nerve innervate the parasympathetic NS?
vagus nerves
how is the cardiac plexus formed?
Combination of parasympathetic/sympathetic NS together
what happens for pain to be referred?
Visceral and somatic afferents travel along the same pathway as the CNS.
Along the way, info from the viscera is misinterpreted as if it came from a somatic area
where is pain referred to during heart attacks?
neck and left UL
what is the function of a pacemaker?
regulates HR
where can the leads of the pacemaker be inserted?
inserted through subclavian or brachiocephalic veins
how are the leads of pace makers generally placed?
it will vary between
- Single atrial/ventricular
- Atrial & ventricular leads
- Biventricular leads
