SBI 4U: Metablic Processes Regulation of Stress Nervous Response Endocrine Response Quick, sudden Slow, prolonged Increase Heart Rate Increase release of glucose, breakdown of glycogen Diversion of blood and oxygen to needed tissue More glucose available Lots of O2 and glucose = more energy Section 1.3

SBI 4U: Metablic Processes ADRENAL GLANDS located above each kidney made up of a cortex surrounding a medulla the cortex is regulated by hormones the medulla is regulated by nerves both are triggered to release their hormones to deal with stress on the body (physical/emotional) Section 1.3

Short and Long Term Stress Response SBI 4U: Metablic Processes Short and Long Term Stress Response Section 1.3

CORTEX (Long Term Stress) SBI 4U: Metablic Processes CORTEX (Long Term Stress) produces hormones known as Glucocorticoids and Mineralocorticoids and small amounts of sex hormones Section 1.3

SBI 4U: Metablic Processes Glucocorticoids Ex. Cortisol Increases Glucose availability by: increases amino acids (used by liver to convert into glucose) Suppresses insulin – therefore inhibiting glucose uptake into tissues Section 1.3

SBI 4U: Metablic Processes Mineralocorticoids Ex. Aldosterone increase Na+ and H2O reabsorption in kidneys Helps to maintain blood volume and blood pressure Both GC and MC are released in response to Adrenocorticotropic hormone (ACTH) from the anterior pituitary Section 1.3

SBI 4U: Metablic Processes LONG TERM STRESS Hypothalamus Pituitary Adrenal cortex Glucocorticoids Mineralocorticoids Cortisol Aldosterone (Negative feedback) Releasing Hormone ACTH hypothalamus sends a releasing hormone to the pituitary pituitary releases ACTH into the blood ACTH stimulates adrenal cortex to release GCs and MCs Cortisol and aldosterone act to counter the effects of stress on body (increase glucose availability, increase water reabsorption). Section 1.3

MEDULLA (Short Term Stress) SBI 4U: Metablic Processes MEDULLA (Short Term Stress) produces the “Fight or Flight” hormones: Epinephrine and Norepinephrine released in response to nerve signals from hypothalamus to Increase blood glucose levels by stimulating the breakdown of glycogen increase heart rate, breathing rate, metabolism dilate blood vessels and iris of eye Section 1.3

Problems with Prolonged Stress SBI 4U: Metablic Processes Problems with Prolonged Stress Overtime, high blood sugar associated with long term stress leads to: high blood pressure and *increased* water loss These can lead to: Rupture of vessels / clotting Increased Heart Rate and heart attack Hmwk p 383 #1,6-9; p 392 #1-4, 6*, 8* Section 1.3