by allowing glucose to enter
the muscle and adipose tissue cells and by enabling
the storage of glucose in the form of glycogen in the
liver (Guyton and Hall 1996). Brain tissue, however,
does not rely on insulin to absorb glucose, as it is
already fully permeable to it and cannot use other
sources of energy. This explains why low serum blood
glucose is so dangerous. Having a half-life of approximately
six minutes, insulin can be totally cleared from
the body within 10-15 minutes and its production is
controlled via a negative feedback system. If serum
glucose levels drop, so does the insulin secretion,
while glucagon manufacture intensifies. In an
absence of insulin, large quantities of fatty acids are
released into the circulation following the breakdown
of stored triglycerides. This raises the volume of fatty
acids in the liver cells, which are then converted into
aceto-acetic acid. This cannot be metabolised by
peripheral tissues and culminates in a state of
acidosis (Bowen 1999), frequently seen in severe
hyperglycaemia. This can result in hyperventilation as
carbon dioxide is blown off. If bicarbonate production
is reduced, as in pancreatitis, then blood pH can drop to below 7.0, causing death (Steinberg and
Tenner 1994).
by allowing glucose to enterthe muscle and adipose tissue cells and by enablingthe storage of glucose in the form of glycogen in theliver (Guyton and Hall 1996). Brain tissue, however,does not rely on insulin to absorb glucose, as it isalready fully permeable to it and cannot use othersources of energy. This explains why low serum bloodglucose is so dangerous. Having a half-life of approximatelysix minutes, insulin can be totally cleared fromthe body within 10-15 minutes and its production iscontrolled via a negative feedback system. If serumglucose levels drop, so does the insulin secretion,while glucagon manufacture intensifies. In anabsence of insulin, large quantities of fatty acids arereleased into the circulation following the breakdownof stored triglycerides. This raises the volume of fattyacids in the liver cells, which are then converted intoaceto-acetic acid. This cannot be metabolised byperipheral tissues and culminates in a state ofacidosis (Bowen 1999), frequently seen in severehyperglycaemia. This can result in hyperventilation ascarbon dioxide is blown off. If bicarbonate productionis reduced, as in pancreatitis, then blood pH can drop to below 7.0, causing death (Steinberg andTenner 1994).
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