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Endocrine Notes. Biology. Function. Chemical “messages” (hormones) that affect body functions & development Slower message system compared to nervous system Hormones circulate through the circulatory system ( takes longer than nervous system). Body Functions Affected. Regulate….. Mood
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Endocrine Notes Biology
Function • Chemical “messages” (hormones) that affect body functions & development • Slower message system compared to nervous system • Hormones circulate through the circulatory system (takes longer than nervous system)
Body Functions Affected Regulate….. • Mood • Blood pressure • Growth & development (Testosterone, Estrogen)
Hormones – Chemical messenger • Hormones • Chemical messenger that targets glands or organs • Enter the bloodstream • Takes seconds to hours to respond to stimuli
Endocrine glands • Produce & secrete chemicals/hormones • Glands are dispersed throughout the body • Near target organs
Major Endocrine Glands • Pituitary • Thyroid • Pineal • Hypothalamus • Adrenal • Pancreas • Ovaries • Testes
Pituitary Gland- “Master Gland” Function Stimulates secretion of thyroid hormones Retains water Controls blood pressure Growth & Development Sperm and egg production Disorders Too much growth hormones = gigantism Too little growth hormone = dwarfism
Thyroid Gland Function Controls metabolism Disorders: Too much thyroxin = hyperthyroidism Too little thyroxin = hypothyroidism
Pineal Gland Functions: Regulates body clock (Circadian rhythm)
Hypothalamus Gland Function Stimulates/inhibits production of various hormones
Pancreas • Function: Hormones = insulin and glucagon Regulates blood glucose levels • Disorders: Pancreas fails to produce or properly use insulin = Diabetes
Adrenal Gland Functions: Release adrenalinein the body (deal with stress) Fight or flight response Anti-inflammatory
Ovaries • Functions: Secretes estrogen and progesterone (ovulation and menstruation) Secondary sex characteristics
Testes • Functions: Pair ofreproductive glands that produces sperm Secretetestosterone(masculine characteristics)
Response Pathway Nervous and Endocrine systems • You smell hot delicious food • Olfactory sensory neurons send message to thalamus • Thalamus sends message to area of brain that will identify odor & location of food • Brain tells motor neurons to fire muscle movement towards food • While you are moving toward food, your hypothalamus checks your hunger level • If hungry your brain sends a message to stimulate production of specific hormones involved in digestion • Gets your body ready to digest food
Feedback Loops • Encourage or inhibits (stops) something from happening • Feedback loops = the product from the initial signal encourages of inhibits an event • The level of one substance influences the level of another substance
Feedback loops • Two Types • Negative (inhibits) • Positive (encourages)
Negative Feedback • Product released turns off (inhibits) the process • Example = temperature control • Hypothalamus monitors body temperature • Senses abnormal temperature = stimulate sweat of shivering • Once the normal range is reached the hypothalamus stops the response
Positive Feedback • Product released encourages (continues) the process • Example = childbirth • Oxytocin (hormone) is released during labor • Oxytocin intensifies the contractions • Contractions stimulate more oxytocin to be released