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what are hormones, and what are they good for?

what are hormones, and what are they good for?. substances produced in one part of the body that are carried in the bloodstream and have effects on other parts of the body. a way for one part of the body to communicate with other parts of the body

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what are hormones, and what are they good for?

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  1. what are hormones, and what are they good for? substances produced in one part of the body that are carried in the bloodstream and have effects on other parts of the body a way for one part of the body to communicate with other parts of the body a way for the body to coordinate responses in multiple parts of the body at the same time a way to control a process that needs to vary over time

  2. endocrine system body function hormone(s) (examples) digestion, basal metabolism, etc. insulin, noradrenaline, thyroid hormone, corticosteroids water and salt regulation, excretion, etc. vasopressin, prolactin calcium metabolism calcitonin growth and development growth hormone, thyroid hormone reproductive organs & reproduction FSH, LH, estrogen, prolactin, testosterone progesterone

  3. types of hormones steroid hormones - derived from cholesterol peptide hormones - transcribed from genes (e.g. insulin, melatonin, adrenaline) modified amino acids(e.g. thyroid hormone)

  4. control of levels of hormones 1) via both positive and negative control (e.g. oxytocin) 2) negative feedback systems e.g. CSH - ACTH - corticosteroid thyroid stimulating hormone (TSH) - thyroid hormone follicle-stimulating hormone (FSH) - sex steroids

  5. some endocrine glands (and examples of hormones produced there) pituitary gland (in the brain) (thyroid stimulating hormone, growth hormone, prolactin) thyroid (in the throat) (thyroid hormones) adrenal (on top of the kidney) (aldosterone, corticosteroids) pancreas (accessory digestive organ) (insulin, glucagon) kidney (erythropoietin) reproductive (ovaries/testes) (LH, FSH, sex steroids) Kidney training.seer.cancer.gov

  6. an example: the stress response ("flight or fight") and corticosteroids a stressful situation causes release of these steroids from the adrenal gland (on the kidney) the hormone causes a rise in the levels of glucose in the blood. what for?? The Lapland longspur, Calcarius lapponicus, in Thule, Alaska short, dangerous breeding season in harsh conditions these birds reduce their stress response during breeding Dr. John Wingfield University of Washington

  7. release of corticosteroids under stress involves a few steps 1. corticotropin releasing hormone (CRH) is released from neurons in the brain 2. that causes the release of corticotropin (ACTH) in the pituitary gland of the brain; ACTH then enters the bloodstream 3. when ACTH reaches the adrenal gland on the kidney, corticosteroid is released, causing the stress reponse 4. corticosteroids then negatively feedback on the brain, shutting down CRH and ACTH production − neurons in the brain + CRH − pituitary gland + ACTH cortico- steroids adrenal gland stress response

  8. researchers at the Max Planck Institute of Psychiatry in Germany bred a mouse that was mutant for CRH to study the role of corticosteroids in the stress response they took these mutant mice and compared them to normal mice under a variety of lab tests they also wanted to test the relationship between stress and alcohol withdrawal they compared activity patterns in an "open field test", and also their reponse to a stressful situation (light/dark box test) Small Animal Behavior Core Laboratory Medical College of Georgia

  9. "open field test" Timplet al. Nature Genetics 1998

  10. light/dark box test Timplet al. Nature Genetics 1998

  11. light/dark box test Timplet al. Nature Genetics 1998

  12. light/dark box test Timplet al. Nature Genetics 1998

  13. Does stress impair memory? In these experiments normal mice were taught to find a submerged platform in a tank of cloudy water picture from: Paul Kenyon University of Plymouth, UK de Quervain et al. Nature 1998

  14. mice under different conditions of stress were then tested for their ability to remember where the platform was. This is how they judged the mice's response: picture from: Paul Kenyon University of Plymouth, UK de Quervain et al. Nature 1998

  15. exposure to stress 2 minutes and 4 hours before a test did not effect the mice's memory, but exposure to stress 30 minutes before an exam caused a temporary memory loss!! picture from: Paul Kenyon University of Plymouth, UK de Quervain et al. Nature 1998

  16. injection of hormone in humans has a similar effect! corticosteroid, 25 mg new words introduced .........24 hours before test... ...24 hours before test......24 hours before test injection of corticosteroid.....1 hour before test...........1 hour before new ........ just after new or placebo words introduced words introduced de Quervain et al. Nature Neuroscience 2000

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