Anatomy: Vasculature and Innervation of the Heart

AV node

AV node is located in the interatrial septum superior to the opening of the coronary sinus

left coronary artery

arises from the aorta above the left cusp of the aortic valve and feeds blood to the left side of the heart divides into anterior interventricular branch and circumflex coronary arteries

posterior descending artery

One of the primary branches of the right coronary artery providing blood to the posterior wall of the heart once it turns down the posterior interventricular sulcus

Right dominant heart

Posterior descending artery arises from RCA (85%)

left dominant heart

Posterior descending artery arises from the left circumflex artery (8%)

right coronary artery

RV, RA, posterior 1/3 of septum, AV and SA nodes goes through the right atrioventricular sulcus gives off a marginal branch to the right ventricle gives off branch to sino atrial node and passes inferiorly in the sulcus gives off branch to av node on posterior side gives off posterior interventricular artery

thrombus

epitheial linings being damaged causing vascular lesions. One such lesion is a thrombus clot that forms inside a vessel it can become an embolus if it dislodges and goes to other parts of the body

AV bundle (bundle of His)

fibers in the heart that relay a nerve impulse from the AV node to the ventricles

left coronary artery supplies

left atrium left ventricle portion of right ventricle interventricular septum (anterior 2/3) AV node (can supply SA node in 40% of population from circumflex branch)

left dominant, no RCA heart

left coronary artery supplies the entire heart

cardiac plexus

network of parasympathetic and sympathetic nerves superificial part: located below arch of aorta and between the arch and pulmonary trunk deep part: lies between arch of aorta and bifurication of trachea small branches supply conduction system of the heart coronary vasculature the myocardium of the atria and ventricle

SA node

pacemaker of the heart located in the wall of the right atrium near the opening of the superior vena cava and superior end of crista terminalis

sympathetic cardiac innervation

preganglionic sympathetic nerves from lateral horn T1-T5 postganglionic cells located in cervical and superior thoracic paravertebral ganglia postsynaptic fibers are carried in thoracic (cardiopulmonary) splanchnic nerves contributing to the cardiac plexus and ending in the SA nodes increase heart rate and force of beat

bacteremia

presence of bacteria in the blood can be acquired from trauma to the skin, dental treatments, surgical procedures, and/or infections sepsis- life threatening bacteremia

referred pain from heart attack

squeezing , fullness or pain in the center of your chest pain/discomfort in one or both arms, back, neck, jaw, or stomach cold sweat, nausea, lightheadedness

right marginal artery

supplies the right border (specifically the right ventricle) of the heart does NOT reach the apex

myocardial infarction

the occlusion of one or more coronary arteries caused by plaque buildup (heart attack)

right dominant, no circumflex heart

the right coronary artery loops above/around the aorta and and goes posteriorly on the left side

oblique vein of left atrium

when this vein opens into the great cardiac vein it changes from smooth muscle cells to cardiac muscle this is then called the coronary sinus

sinoatrial nodal artery

a division of the right coronary artery that gives off blood supply to the SA node

parasympathetic cardiac innervation

achieved by the vagus nerve; outflow originates from the vagal nucleus of the medulla which travels to the cardiac branches of the heart; effect of vagal stimulation on the heart is related to HR; increased vagal stimulation = slows conduction of action potentials through the heart and reduces the strength of contraction via acetylcholine postganglionic cells are located in the cardiac tissue (atrial wall and interatrial septum near the SA and AV nodes along coronary arteries) post sympathetic fibers end in the SA and AV nodes and directly on the coronary arteries

circumflex coronary artery

branch of the left coronary artery supplies the left atrium, anterolateral wall of the left ventricle and posterior wall of the left ventricle as the circumflex approaches where the AV sulcus intersects the posterior interventricular sulcus it usually decreases in size but does anastomose with a small branch of the right coronary artery

coronary anastomoses

collateral channels providing alternate blood routes during episodes of blockage between Left Anterior descending and posterior descending arteries within the interventricular sulcus between circumflex coronary and right coronary arteries in atrioventricular sulcus intracoronary anastomosis

Atherosclerosis

condition in which fatty deposits called plaque build up on the inner walls (tunica intima) of the arteries genetics high cholesterol sex (male) age smoking hypertension treatments: lifestyle changes, medication, angioplasty, surgery

Anomalous right coronary artery from the pulmonary artery

coronary artery anomalies arising from the pulmonary artery are rare, result in reversed flow in affected coronary artery blood bypasses the capillary bed of the myocardium leading to a risk of myocardial infarction

Veins of the heart muscle

coronary sinus (main drainage for heart muscle; drains into right atrium) great cardiac vein: runs with anterior intraventricular artery middle cardiac vein: runs with posterior interventricular artery small cardiac vein: runs along right marginal artery/inferior surface of heart small anterior cardiac veins (drain directly into right atrium)

visceral afferent cardiac innervation

follow the path of sympathetics backward visceral sensory pathways participate in reflex action that lower blood pressure and slow heart rate are carried in the vagus nerve VAGUS NERVE does NOT transmit any visceral pain fibers originating in the heart

coronary artery dominance

refers to which coronary A gives rise to the posterior interventricular A right coronary artery is typically dominant (67%) while blood supply from right coronary artery and left coronary artery is about equal

Right coronary artery supplies

right atrium right ventricle posterior 1/3 interventricular septum SA & AV nodes