<prompt> Answer this question truthfullyWhat is acute tubular necrosis ATN, and how does ischemic injury affect blood flow to the glomerulus in this condition?  <response>: <reason> Acute tubular necrosis ATN is a type of kidney injury that can occur due to a variety of causes, including ischemia lack of blood flow to the kidneys. In ATN, ischemic injury results in vasoconstriction of the afferent arteriole, which impedes blood flow to the glomerulus. This can lead to a decrease in glomerular filtration rate GFR and impaired kidney function. ATN is a common cause of acute kidney injury AKI and can be seen in critically ill patients, those who have undergone major surgery, or those who have experienced severe trauma. Treatment of ATN typically involves supportive care and addressing the underlying cause of the injury. 