1. Conductive Arteries – The conducting arteries constitute the most proximal compartment of the coronary arterial system. Their diameter generally varies from 500 μm up to 2 to 5 mm. These are large epicardial coronary arteries that function as a capacitive function for blood flow. They have very low resistance to blood flow and therefore the pressure drop along the conducting arteries is negligible. Conductive arteries have the intrinsic characteristic of maintaining shear stress by modifying epicardial dilation. This characteristic is called flow-dependent expansion responsiveness. They do not respond very well to intravascular pressure or metabolites. [1]Prearterioles – Prearterioles are the intermediate compartment of the conducting arteries. Their diameter varies from approximately 100 to 500 μm. The pressure drop at the level of the prearterioles is significant. They have thick walls and an extra-myocardial position due to which they do not encounter metabolites and therefore do not respond to them. Prearterioles respond better to flow-dependent dilation than conductive arteries. [1]Arterioles - Arterioles constitute the most distal compartment of the coronary arterial system with a diameter less than 100 μm. The pressure drop along the arterioles is considerable and greatest in all three compartments of the coronary arterial system. They are also most sensitive to flow-dependent dilation during epicardial changes due to variation in blood flow. They are responsible for the metabolic regulation of coronary blood flow. Indeed, they react very well to changes in the concentration of intramyocardial metabolites. They are also much more sensitive to changes in intravascular pressure than other compounds...... middle of article ......onian_fluid12. [Online]. FTP available: http://ocw.usu.edu/Civil_and_Environmental_Engineering/Fluid_Mechanics/CEE3500_L3_Properties2.pdf13. [Online]. FTP available: http://en.wikipedia.org/wiki/Coronary_flow_reserve14. [Online]. FTP available: http://en.wikipedia.org/wiki/Hemostasis15. [Online]. FTP available: https://www.lef.org/protocols/heart_circulatory/blood_clot_01.htm16. [Online]. FTP available: http://en.wikipedia.org/wiki/Turbulence17. [Online]. FTP available: http://www.britannica.com/EBchecked/topic/609625/turbulent-flow18. [Online]. FTP available: http://www.cvphysiology.com/Hemodynamics/H007.htm19. [Online]. FTP available: http://link.springer.com/chapter/10.1007/978-1-4419-0730-1_10#page-120. [Online]. FTP available: http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Microvascular-Angina_UCM_450313_Article.jsp