Blood Supply & Nerve Supply Of Heart

BLOOD SUPPLY OF HEART
  • Anterior 2\3 of interventricular septum is supplied by ascending br. Of LAD artery. While posterior part of IVS is supplied by RCA.
  • Terminal branch of the right coronary artery, the posterior interventricular artery, is termed the posterior descending artery (PDA)
  • Short left coronary A- main stem vessel.
  • Rt coronary artery (RCA)Diameter less than LCA
  • LAD -Left anterior descending artery (widow's artery/ anterior interventricular artery) is a branch of left coronary artery a is mostly affected by atherosclerosis.
  • Kugel's artery, diagonal artery and obtuse marginal artery are branches of LCA
  • Branches of right coronary artery are: Right conus artery, marginal artery, anterior ventricular branches, posterior ventricular branches, posterior interventricular artery and atrial branches.Branches of the right coronary supply the right atrium and ventricle and, variably, parts of the left chambers and atrioventricular septum.
  • The first branch (arising separately from the anterior aortic sinus in 36% of individuals) is the arteria coni arteriosi or conus artery.
  • This is sometimes termed a 'third coronary' artery, but as a similar vessel comes from the left coronary, it is more correctly named the right conus artery.
  • It ramifies anteriorly on the lowest part of the pulmonary conus and upper part of the right ventricle.
  • It may anastomose with a similar left coronary branch from the left anterior descending artery to form the 'anulus of Vieussens', which is a tenuous anastomotic 'circle' around the rightventricular outflow tract.
  • RIGHT DOMINANT HEART:
  •  In 90% cases, right coronary artery gives posterior interventricular artery.
  • LEFT DOMINANT:
  •  in 10% cases, posterior interventricular artery is a branch of circumflex artery.
BLOOD SUPPLY OF CONDUCTING SYSTEM OF THE HEART:
  • SA NODE: right coronary artery(nodal branch) (65%), left coronary artery (35%).
  • AV NODE, AV BUNDLE & BUNDLE OF HIS: right coronary artery.
  • RIGHT BUNDLE BRANCH: left coronary artery
  • LEFT BUNDLE BRANCH: mostly by left coronary artery, few parts by right coronary artery.
VEINS OF THE HEART
  • Coronary Sinus:
  1. Largest vein of the heart situated in the left Posterior coronary sulcus
  2. Ends by opening into the posterior wall of the right atrium b/w IVC opening & AV orifice.
  3. Orifice of coronary sinus is guarded by thebesian valve while IVC orifice is guarded by rudimentary Eustachian valve (SVC orifice has no valve).
  • The tributaries are:
  1. Great cardiac.V (anterior interventricular vein) → Enters the left end of coronary sinus at its origin,
  2. Middle cardiac V (posterior interventricular vein) → Joins the middle part of coronary sinus
  3. Small cardiac vein → Joins the right end of coronary sinus
  4. Posterior vein of left Ventricle → Ends in middle of coronary sinus
  5. Oblique.V of left atrium of Marshalls → Terminates in left end of coronary sinus (Develops from left common cardinal Vein (duct of curier)
  • Right marginal.V
2. Anterior Cardiac Veins:
  1. These veins are 3 or 4 small veins which run parallel to each other on the anterior wall of right ventricle Opens directly into the right atrium through its anterior wall.
  2. 3. The besian Veins (Venae Cordis minimi)
  3. They are the numerous small veins present in all the four chambers.
  4. Open directly into the cavity of heart.
  5. The venae Cordis minimi are more numerous on right side (left side infarcts are more common.
NERVE SUPPLY OF HEART:
  • Sympathetic innervation to heart is by T1-T5.
  • Sympathetic fibres intermingle with vagus to form cardiac plexus.
  • SA node is supplied by right vagus/parasympathetic (inhibitory) and right Sympathetic (excitatory) system

Superficial cardiac plexus Deep cardiac plexus
Location Below the arch of aorta in front of right pulmonary artery In front tracheal bifurcation and behind the arch of aorta
Components Superior cervical cardiac branch of left sympathetic chain & Inferior cervical cardiac branch of left vagus All the cardiac branches derived from all the cervical & upper thoracic ganglia of the sympathetic chain.
Cardiac branches of vagus a RLN except those forming superficial plexus.
LYMPHATIC DRAINAGE OF HEART:
  • Lymphatics drain into tracheobronchial +Mediastinal LN.
Exam Question
  • The right coronary artery supplies SA node, AV node and AV bundle of Right atria & ventricles & parts of left chambers & AV Septum
  • Right coronary artery supplies SA node
  • Cardiac dominance is determined by coronary artery Supplying circulation to the inferior portion of the interventricular septum
  • S A node is supplied by nodal branch of RCA
  • SA node is supplied by right vagus/parasympathetic (inhibitory) and right Sympathetic (excitatory) system
  • Rt coronary artery (RCA)Diameter less than LCA
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