The viability of the heart following severely restricted blood flow is dependent on the ability of the heart to provide this collateral circulation.
12.
Patients often survive on the collateral circulation from the back ( posterior ) of the circle of Willis, arising from the basilar artery.
13.
With time, collateral circulation is formed and the eggs disseminate into the lungs, where they cause more granulomas, pulmonary arteritis and, later, cor pulmonale.
14.
All these vessels anastamose or join to connect the first part of the subclavian with the third part of the axillary, providing a collateral circulation.
15.
The anastomotic network surrounding the scapula provides an alternate path for collateral circulation to the arm from arteries including the dorsal scapular artery and suprascapular artery.
16.
Larger PEs, which tend to lodge centrally, typically cause dyspnea, hypoxia, fainting, but are often painless because there is no lung infarction due to collateral circulation.
17.
A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are small, weak, and prone to bleeding, aneurysm and thrombosis.
18.
Even though the main vessels to the leg are blocked, enough blood can get to the tissues in the leg via the collateral circulation to keep them alive.
19.
Obstruction of pulmonary arteries due to emboli from dying worms is more likely to be fatal in cats than dogs because of less collateral circulation and fewer vessels.
20.
Here the smallest cardiac veins return blood into the heart chambers from the capillary bed in the muscular cardiac wall, enabling a form of collateral circulation unique to the heart.
