31 terms

Coronary Circulation

Coronary Circulation
A system of blood vessels that serve the wall of the heart, considered the most variable aspect in Cardiac Anatomy.
80 yr old Heart
will beat more than 3 billion x's & pump more than 200 liters of blood because it requires abundant supply of oxygen and nutrients.
has it's own supply of arteries and capillaries that deliver blood to every muscle cell.
Circulation at Rest
the coronary blood vessels supply the myocardium w/ about 250mL of bpm which constitutes 5% of circulating blood to the metabolic needs of the heart.
R&L Coronary Artery
orifices of these 2 areteries lie deep in the pockets formed by the aortic valve cusps.
Left Coronary Arterty (LCA)
travels through the coronary sulcus under the left auricle and divides into 2 branches.
*Anterior Interventricular Branch
*Circumflex Branch
Anterior Interventricular Branch
travels DOWN the anterior interventricular sulcus to apex, rounds the bend, travels short distance UP the posterior side of the heart which then joins posterior interventricular branch. This artery supplies blood to both ventricles and anterior 2/3 of the interventricular septum.
Circumflex Branch
continues around the L-side of the heart in the coronary sulcus.
Left Marginal Branch
that passes down the left ventricle.
Right Coronary Artery (RCA)
supplies the right atrium and sinoatrial node (pacemaker) continues along the coronary sulcus under R-auricle and gives off 2 branches.
Right Marginal Branch
runs down toward the apex of the heart and supplies the lateral aspect of the R-atrium and Ventricle.
Posterior Interventricular Branch
branch travels down the corresponding sulcus and supplies the posterior walls of both ventricles and the posterior portion interventricular septum and ends by joining the Anterior Interventricular branch of the LCA.
Cardiac Muscle
energy demand is critical in this muscle, if interruption of blood supply in myocardium can cause necrosis.
pathological tissue death due to such causes as infection, trauma, or hypoxia.
Myocardial Infarction
a fatty deposit or blood clot in a coronary artery, can cause heart attack.
Collateral Circulation
can supply the heart tissue with blood if primary route becomes obstructed.
Organ Blood flow
blood flow peaks when ventricles contract and eject blood into the arteries and diminish when ventricles relax and refill
Why Heart Relaxes
*Contraction of the myocardium compresses the arteries and obstructs blood flow.
*When ventricles contract, aortic valve is forced open and cusps cover the opening to coronary arteries blocking blood.
*When relax, blood in aorta briefly surges back to heart.
Ventricular relaxation
coronary blood vessels blood flow increases
Venous Drainage
refers to the route by which blood leaves an organ.
Thebesian Veins
smallest cardiac veins, where 5-10% of coronary blood empties from these multiple small veins.
Great Cardiac Vein
collects blood from the anterior aspect of the heart and travels alongside the anterior interventricular artery, carries blood from apex toward coronary sulcus.
Posterior Interventricular Vein (middle cardiac)
found in posterior interventricular sulcus, collects blood from posterior aspect of the heart, also carries blood from apex UPward and drains into same sinus.
Left Marginal Vein
travels from point near the apex UP the L-margin and also epties into coronary sinus.
Coronary Sinus
large transverse vein in the coronary sulcus on posterior side of the heart, collects blood from 3-aforementioned,empties blood into R-atrium.
most obvious physiological fact about the heart
Rhythmicity beat
regular intervals typically about 75 bpm in resting adult.
Heartbeat trigger
by a pacemaker in the nervous system
Vertebrate heartbeat
said to be myogenic because signals originate within the heart itself.
continues it's own rhythmic pulsations, cardiocytes said to be inherently
Heart dependency
does NOT depend on nervous system for its rhythm, has its own pacemaker and electrical system.