During surgical stress, which is not seen: March 2011
Ans. B: Increased insulinMost of the stressful stimuli that increase ACTH secretion also activate the sympathetic nervous systemAlpha adrenergic stimulators (epinephrine and norepinephrine) inhibits insulin secretionThe condition in which sympathetic nervous system, including the sympatho-adrenal medullary system is activated are: fear, trauma, haemorhhage, fluid loss etc.Stressful stimuli stimulates secretion of growth hormone in humansStress hormonesThey are coisol, GH and norepinephrineThey are released at periods of high stress.Stress hormones rise in the body during any neuroendocrine reaction such as surgery and they remain high as long as 72 hours, after which all these hormones return to their normal level, the last being coisol.Stress hormones act by mobilizing energy from storage to muscles, increasing hea rate, blood pressure and breathing rate and shutting down metabolic processes such as digestion, reproduction, growth and immunity.Stress response to surgeryIt is characterized by increased secretion of pituitary hormones and activation of the sympathetic nervous system.The changes in pituitary secretion have secondary effects on hormone secretion from target organs.For example, release of coicotrophin from the pituitary stimulates coisol secretion from the adrenal coex.Arginine vasopressin is secreted from the posterior pituitary and has effects on the kidney.In the pancreas, glucagon is released and insulin secretion may be diminished.The overall metabolic effect of the hormonal changes is increased catabolism which mobilizes substrates to provide energy sources, and a mechanism to retain salt and water and maintain fluid volume and cardiovascular homeostasis.
Increased ACTH
Increased insulin
Increased norepinephrine
Increased GH