1. HormoneSourceEffect on Body Maintain Homeostasis Type of Hormone MelatoninPineal GlandSleep patterns Regulate Circadian Rhythm Amino Acid Derivative ThyroxineThyroidWeight gain/lossRegulate MetabolismAmino Acid Derivative AdrenalineAdrenal Gland Stimulates the ‘fight or flight’ response Regulate Heart RateAmino Acid Derivative Somatotrophin (GH)Pituitary GlandIncreases cell growth Regulate growth and development Polypeptide InsulinPancreas Lowers blood-glucose levels Regulate Blood- Glucose Levels Polypeptide GlucagonPancreasRaises blood-glucose levels Regulate Blood- Glucose Levels Polypeptide *Examples of lipid (steroid) hormones are cortisol, estrogen and testosterone

3.  Regulate physiological functions  Negative Feedback Loop  Oppose stimulus  Positive Feedback Loop  Increase stimulus

4.  Increases the stimulus  Good and Bad  Example of Beneficial (good): Childbirth  stretching of the uterus triggers the secretion of a hormone, oxytocin, which stimulates uterine contractions and speeds up labor  Example of Detriment (bad): Heart Attack  if the death of a small area of heart tissue triggers a heart attack the heart pumps an inadequate amount of blood. Thus, the heart muscle itself is deprived of blood flow, and continues to die  heart failure  mortality

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6.  More common in the human body  Keeps body ‘normal’  Blood-Glucose levels  glucose is absorbed in the intestine  level of glucose in blood rises  stimulates endocrine cells in the pancreas to release insulin  blood glucose levels fall.  level of blood glucose falls sufficiently  the stimulus for insulin release disappears and insulin is no longer secreted.