Blood Flow Lecture Note | The University Of Western Ontario

University:
The University Of Western Ontario
Course:
ANAT 2200B | Systemic Anatomy of the Human Body
Academic year:

2022
Views:

177

Pages:

3
Author:

Kyuwon J.

Blood flow in Coronary Arteries ● Aortic pressure [A] ○ in Systolic ○ Aortic pressure increases dramatically ○ left ventricular ejection ■ reaching up to 120 mmHg ○ peak systolic, the pressure will fall slowly as blood flows back into the systemic circulation ○ Aortic pressure will give driving force on coronary artery ● Left coronary Artery flow [B] ○ blood flow decreases dramatically in systole ■ contracting left ventricle will compress on intramural coronary vessel ■ impeding perfusion even with high aortic pressure ■ Most left coronary artery occurs during diastole ● Right coronary Artery Flow [C] ○ Flow decreases slightly in systole but not as dramatic as A and B ■ Right ventricle generates lower systolic pressure ■ compresses on its coronary vessel with lesser force ○ diastolic is still greater Review ● Aorta ○ high pressure is systol ○ slower decline in diastole ● Left Coronary Artery ○ Small systolic flow ○ max diastolic flow ● Right Coronary Artery ○ flow across systole and diastole ○ balanced pressure Blood flow reduced ● Resting Blood flow ○ moderate lumen narrowing ■ resting blood flow tends to be constant ■ coronary autoregulations ● arterioles dilates = maintain adequate flow even with upstream narrow ■ when lumen narrows over 70% resting begins ● fall significantly ■ patients may be in asymptomatic in reest ● will notice when severe stenosis occurs ● Maximal blood flow (exercise) ○ reduced earlier than resting flow ○ 40%-50% narrowing ○ artery is not able to supply sufficient blood flow ○ angina symptoms typically will appear during exertion ● Resting flow a ○ maintaining until severe narrowing ○ ~70% ● Maximal flow b ○ Compromised ○ Early effect ○ 40-50%