1. Key points of the endocrine system.
    • -ductless glands
    • -specific target cells
  2. Overall functions of the endocrine system.
    • -regulate organic metabolism
    • -regulate eater and electrolyte balance
    • -induces heat to help body cope with stresses
    • -promote growth and development
    • -control reproduction
    • -regulate RBC production
    • -CV & GI control
  3. Complexity of endorcine system.
    • -1 gland makes & secretes multiple homones
    •     ex: pituitary
    • -1 homone from multiple glands
    •   -ex: somatostatin
    • -1 homone goes to multiple targets 
    •    ex: vasopressin
    • -cyclic secretion patterns
    • -multiple hormones go to the same target
    • -insulin vs. glucagon
  4. Complexity of endocrine system cont.
    • -same chemical messanger can be either nt or homone
    • ex= NE
    • -some organso of endocrine system perfrom non endocrine functions
    • ex= testes, pancreas
  5. What are the effects of the endocrine proportional to?
    the amount of free homrone in plasma

    ex: as secretion increases, amount of homone increases
  6. Metabolism of free hormone:
    • ex: thyroid hormone
    • -T3 more potent than T4
  7. Plasma protein binding of free hormones:
    • lipophilic hormones
    • -unbound H is monitored
  8. Free hormones:
    Metabolic inactivation=
    • liver, kidney,etc.
    • clearance
  9. In negative feedback of free hormones:
    -output conteacts a change in input
  10. In positive feedback of free hormone:
    • -amplifies intital effect of hormone
    • -a "vicous cycle"

    ex: blood clot, allergic reaction, childbirthing + breastfeeding
  11. What are Neuroendocrine reflexes?
    produce sudden increase in hormone secretion

    ex: adrenaline rush
  12. Dinural (cicardian) rhythms are?
    • -hormones that fluctaute over 24 hours
    • -happens on a daily activity

    • ex: melatonin
    • -melatonin is highest at the night time 
  13. Endocrine disorders:

    • 1*= decrease in secretion due to glandular abnormality
    • =genetic, dietary, chemical toxicity, immunologica, 2nd to disease process, Iatrogenic ( some other disease but physicans medicine causes gland not to function), idiopathic
    • 2*= decrease in secretion as a result in decrease in stimulus by trophic hormone
  14. Endocrine disorders: Hypersecretion
    • 1*=increase in secretion due to glandular abnormality
    • 2*=increase in secretion due to increase stimulation of gland
    • -tumors, immunological factors ( antiboitics that mimic TSH), substance abuse
  15. Defintion of trophic hormone:
    • 1. grow
    • 2. secrete its hormone
  16. Abnormal target cell responsiveness:
    • -lack of receptos
    • ex: testicular feminization syndrome=
    •           -external genitalia looks female
    •          - short blind puch vagina
    •          - no unterus, no ovaries, no fallopian tubes
    •          - testes located in abdomen (not descended)
    • -lack of cellular component in response pathway
    • ex: enxyme, 2nd messanger
  17. Problems with Down Regulation:
    • -so miuch homrone the cell stops responding to it
    • ex: insulin insensitivity, individuals eat carbs all the time & insulin is chronically high

    (-more internalization of receptor and u cannot replace empty receptors to membrane, so u lose response to insulin & you have chronic high glucose)
  18. Effect of Other Hormones:
    -one hormone must be present for full effect of another hormone
  19. Effects of other hormones:
    • several hormones are complimentary
    • -combines effect greater than that of one
  20. Effects of other hormones:
    ex= progesterone prevents estrogen from causing uterine contactions during pregancy
  21. Hypothalamus
    Intrgration center:
    • -body temperature
    • -thirst and appetite
    • -uterine contraction & milk ejection
    • -ANs coordination center
  22. 2 most imporant parts of Hypothalamus:

    -Anterior Pituitary Hormones
    -Posterior Pituitary Hormones
    • Bridge to endocrine:
    • -stimulates or inhibts AP hormones secretion via releasing or inhibting hormones
    • -synthesizes P.P. hormones
  23. what is a biological clock?
    • -has a 24 cycle for body functions
    • ex: temp, gene expression, behavior, hormone secretion
  24. what is the master clock?

    • Suprchiasmatic nucleus (SCN)
    • -cluster of neuron cell bodies above optic chiasm
    • -input from each eye (establishment of inherent daily rthyms)
  25. What are clock proteins?

    • -"Self starting" generes of SCN neurons = synthesis of proteins
    • **see synoposis made in notes
  26. How do you synchronize biological clock with environment?
    • -SCN is reset dauly by external cues (light intensity)
    • **pineal gland secretes melatonin to synchronize

    -if not adjusted, individuals circardian rhyms falls out of sync with day and night
  27. Pineal Gland:

    Light pathway=
    • -different than for vision
    • -specialized retinal ganglion cells
    • -Pineal gland responds with cycle of melatonin (24 hr cycle)
  28. Pineal Gland:

    • -idolamine
    • -secreted during periods of darkness
    • -proposed roles=
    • -can induce natural sleep, inhibits sex hormones, (puberty initated by melatonin levels), (in other species: hibernation, seasonal breeding), birth control (high levels shut down ovulation), antioxidant, slows againg process, enhances immunity (also slows regression of thymus)
  29. Pituitary Gland: Hypophysis

    Has two distinct tissues!
    -Anterior Lobe: true glandular tissues "Adenohypophysis"

    • -Posterior Lobe: extension of hypothalamus "Neurohyphophysis"
  30. Neurohyphophsis:

    -Has 2 populations of neurosecretary neurons?
    • -Suproptic Nucleus SON
    • -Paraventricular Nucleus PVN
  31. Neurohypohsis?
    • -terminals in posterior lobe
    • -SON & PVN contain neurons that produce peptide hormones (but only one hormone produced per cell!)
    • -Hormones:
    •     - Vasopressin & Oxyctocin
  32. Vasopressin Hormone:

    aka Antidiuretic Hormone

    -release triggered by?
    • Release Triggered By:
    • -hypothalamic osmoreceptors
    • -left atrial volume receptors
    • -acute infection, pain, trauma (inappropriate H20 retention)

    • Targets:
    • -kidney
    • -arteriolar smooth muscle (**Crucial during hemorrhage)
  33. Oxytocin:

    -Release triggered by?
    -Also influence?
    • Released by:
    • -stimulation of cervical mechanoreceptors
    • -stimulations of mechanoreceptors in nipple
    • Actions:
    • -at uterus, decrease threashold potentioal
    • -at breast, increases myoethithial tone
    • Also influences: maternal bleeding
  34. Anterior Pituitary : Adenohypohysis:

    -AP hormone secretion regulation
    • -hypophsiotropic hormones
    • -secreted in pulses
  35. Define Hypothalamic relasing hormons.

    Define hypothalamic inhibiting hormones.
    hypothalamic releasing hormones= stimulates release of hormones from anterior piuitray cells

    hypothalamic inhibiting hormones= inhibits release of hormone from anterior pitiuitary
  36. Define Hypothalamic- Hypophyseal Portal System.
    • -capillary to capillary link
    • -direct route from hypothalamus to pituitary 

    (neurosecretory neurons terminate on the capillares of portal system)
  37. Adenohypophysis:

    -Multiple inputs regulate hypophysiotropic hormones
    • -can be either stimulatory or inhibitory
    • -neural connections with other portions of the brain
    • -environment factors
    • -chemical signals: hypothalamic regions unprotected by blood brain barrier
  38. Adenohypophysis:

    Typically target glands hormones suppress:
    • suppress secretion of trophic hormones that is driving it
    • -negative feedback control: once its hormonal signal is activated, its secretion does not continue unabated
  39. Adenohyphosis:

    5 major cell populations produce 6 six major hormones!
    • -Lactotropes: Prolactin (protein similar to GH)
    • -Somatropes: Growth Hormone 
    • -Thyrotropes: TSH
    • -Corticotropes: ACTH
    • -Gonadotropes: FSH & LH 
  40. AdenohypphosisL

    Which are trophic hormones?
    • -FSH & LH
    • -ACTH
    • -GH
    • -TSH
  41. Growth:

    Under influence of:
    • -under influence of growth hormone
    • -net synthesis of proteins
    • -increase in growth of long bones
    • -increase in # of soft tissues
  42. Other factors that affect growth:
    • -genetics
    • -diet
    • -freedom from disease & stressful environment
    • -normal levels of growth influencing hormones:
    •    **thyroid hormone, insulin, sex hormones
  43. Growth:
    -Not coninous
    -Fetal growth?
    • Fetal growth:
    • -placental hormones
    • -GH not involved!!!
    • -genetic/environmental factors
    • Children:
    • -postnatal growth spurt (1st 2 yrs)
    • -pubertal growth spurt ( 11 yrs female, 13 yrs male)
    • **Both T and E2= halt bone growth @ end of puberty 
  44. Metabolic effects on growth hormone"
    • -GH is most abundant AP hormone secreted
    • ---binds directly to target tissues: adipose, skeletal muscles, liver

    **also stimulates protein synthesis
Card Set
physiology endocrine exam 5