1. 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

2. 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

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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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