Perivascular spaces surround perforating arterioles
and venules as they course from the subarachnoid space through the brain parenchyma and serve as an important drainage system for interstitial fluids and solutes in the brain.
Intraluminal microthrombi are defined by the presence of thrombi with or without organization, occluding at least 1 capillary or small arteriole
in the LP and/or submucosa (Figure 6, A and B).
proposed in 1995 a pathway involving RBC release of ATP into the vessel lumen based on the knowledge that RBCs release ATP in response to hypoxic conditions and that ATP application results in significant increases in RBC supply rate to both arterioles
and venules at the end of a capillary network.
These lesions typically appear round or oval in shape and adjacent to a retinal arteriole
In the active stage, BRAO is best assessed by fundus fluorescein angiography (FFA), in which it typically appears as multifocal fluorescence in the arteriole
This is secondary to renal vasoconstriction of the afferent arteriole
As the pulmonary arterioles
continue branching, they extend into single vessels 13 pm in diameter.
GPA is classified as small vessel vasculitis preferentially involving capillaries, arterioles
It then plunges inward through smaller vessels called arterioles
before squeezing down into capillaries so thin that red blood cells must travel single file.
PAH begins when tiny arteries in the lungs, called pulmonary arterioles
, become narrowed, blocked or destroyed.
Diabetic nephropathy, one of the causes of end-stage renal disease (ESRD) and frequently found in subjects with diabetes, is a condition characterised pathologically by hyalinisation of arterioles
27) has measured renal arteriolar diameter using a vascular cast technique and have found that the afferent arterioles
were constricted while the efferent arterioles
were dilated in DOCA-salt hypertensive rats.
Small vessel disease occurs when the brain arterioles
become less flexible and interfere with blood flow, which can lead to stroke or cognitive impairment.
The hemorrhagic nature of the infection is a consequence of the invasion of venules by the bacteria resulting in secondary thrombosis of arterioles
regulate the amount of blood that enters these capillary networks.