Final answer:
Abnormal flow characteristics near a proximal anastomosis involve problems in blood circulation due to surgical connections or disease processes such as blockages, coarctation of the aorta, or varicose veins. Natural anastomoses like arteriovenous connections bypass capillary beds and are susceptible to different kinds of flow abnormalities, especially when affected by pathologies like tumor-induced microvasculature changes.
Step-by-step explanation:
The question pertains to the abnormal flow characteristics near a proximal anastomosis, which is a surgical connection made between blood vessels. Anastomosis is crucial because it allows blood to circulate even if there may be partial blockage in another branch of the circulatory system. An example of natural anastomosis is the arteriovenous anastomosis, which is a short vessel directly connecting an arteriole to a venule, bypassing capillary beds.
Abnormal flow characteristics can occur when there is a flaw in the vessel connections or a disease process affects the blood vessels, such as coarctation of the aorta, which is a congenital condition leading to a narrowed segment of the aorta. In heart anastomoses, the channels are quite small, making the heart susceptible to damage from coronary artery blockages, which can result in myocardial infarction.