Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hormones and stress

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The adrenal glands mobilize responses to stress Hormones from the adrenal glands help maintain homeostasis when the body is stressed Adrenal medulla –Nervous signals from the hypothalamus stimulate secretion of epinephrine and norepinephrine –These quickly trigger the fight or flight response

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Adrenal cortex –Chemical signals (ACTH) stimulate secretion of corticosteroids, including glucocorticoids and mineralocorticoids –Corticosteroids boost blood pressure and energy in response to long-term stress –High blood pressure for extended periods of time can lead to heart and circulation problems (heart attack and stroke).

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings How the adrenal glands control our responses to stress (page 441) Figure Adrenal gland Mineralocorticoids Adrenal medulla SHORT-TERM STRESS RESPONSE 1. Glycogen broken down to glucose; increased blood glucose 2.Increased blood pressure 3.Increased breathing rate 4.Increased metabolic rate 5.Change in blood-flow patterns, leading to increased alertness and decreased digestive and kidney activity STRESS Glucocorticoids ACTH Adrenal medulla Adrenal cortex Kidney Nerve signals Spinal cord (cross section) Nerve cell Epinephrine and norepinephrine LONG-TERM STRESS RESPONSE 1. Retention of sodium ions and water by kidneys 2.Increased blood volume and blood pressure 1. Proteins and fats broken down and converted to glucose, leading to increased blood glucose 2.Immune system may be suppressed Hypothalamus Releasing hormone Anterior pituitary Blood vessel Adrenal cortex

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Anaphylaxis is a severe allergic reaction that occurs rapidly and causes a life-threatening response involving the whole body. Because the reaction is really an overreaction, this is sometimes called a hypersensitivity response. Adrenaline is used to counter act the histamine release that can kill (by reducing blood flow to tissues of the body). The Epipen (page 445) is used to deliver epinepherine Alergies that can kill - Anaphylaxis Figure 26.11

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings