Final answer:
Decreased blood flow to the liver during stress can cause ischemia, leading to hypoxia and potentially resulting in liver impairment. This impairment affects the liver's ability to detoxify blood, causing toxic substances to accumulate. Chronic ischemia or hypoxia can lead to liver diseases such as fibrosis or cirrhosis.
Step-by-step explanation:
A decreased blood flow to the liver during stress affects the liver's ability to function properly. During stress, the body may activate various mechanisms that lead to vasoconstriction and reduced blood flow to the liver. For instance, the limbic system anticipates physical exercise or strong emotions, which can result in the superficial arteries becoming constricted, reducing heat loss and decreasing blood flow to the digestive system, including the liver.
This decrease in blood flow can lead to ischemia (reduced blood flow to a tissue), which if it occurs in the liver can lead to hypoxia (decreased oxygen supply). Over time, chronic ischemia or hypoxia of the liver can cause damage such as fibrosis or cirrhosis. With severe liver impairment, blood may bypass the liver through portal systemic shunts, leading to high levels of toxic substances that impair brain function due to lack of detoxification.
In conditions such as cirrhosis, hepatic encephalopathy can occur even in the absence of portal hypertension. Other diseases such as haemochromatosis, cancer, and conditions that cause an increase in T3 and T4 hormones can also affect liver function during times of decreased blood flow.