1. Which system?
    Hormones released into the bloodstream travel throughout the body
    The Endocrine System
  2. Releases neurotransmitters excite or inhibit nerve, muscle & gland cells
    Nervous System
  3. Which system?
    Results in milliseconds, brief duration of effects
    Nervous System?
  4. Which system?
    Results may take hours but last longer
    Endocrine System
  5. Only affect target cells with specific membrane proteins called receptors
  6. Constantly being synthesized & broken down
    A range of 2000-100,000 receptors / target cell
    Hormone Receptors
  7. Excess hormone, produces a decrease in number of receptors
    -receptors undergo endocytosis and are degraded– Decreases sensitivity of target cell to hormone
  8. Deficiency of hormone, produces an increase in thenumber of receptors
    Target tissue more sensitive to the hormone
  9. Both are master endocrine glands since their hormones control other endocrine glands
    Hypothalamus and Pituitary Gland
  10. Receives input from cortex, thalamus, limbic system & internal organs
  11. Connected to the pituitary gland by a stalk called the infundibulum
  12. Pea-shaped gland found in sella turcica of sphenoid
    Pituitary Gland
  13. Infundibulum attaches it to brain
    Pituitary Gland
  14. Anatomy of Pituitary Gland:
    Connected to hypothalamus by portal veins
    Anterior lobe
  15. Anatomy of Pituitary Gland:
    Ends of axons of neurons found in hypothalamus
    Stores and releases neurotransmitter/hormones intoblood strea
    Posterior lobe
  16. What are the 3 steps of flow of blood to anterior pituitary?
    • 1. Controlling hormones enter blood
    • 2. Travel through portal veins
    • 3. Enter anterior pituitary at capillaries
    What are the 7 major hormones secreted by 5 cell types?
    • 1. Human Growth Hormone (HGH)
    • 2. Thyroid Stimulating Hormone (TSH)
    • 3. Follicle Stimulating Hormone (FSH)
  18. Produced by somatotrophs
    Human Growth Hormone
  19. Common target cells are liver, skeletal muscle, cartilage and bon
    Human Growth Hormone
  20. Increases cell growth & cell division by increasing their uptake of amino acids & synthesis of proteins
    Human Growth Hormone
  21. Produces Thyroid Stimulating Hormone (TSH)
  22. Stimulates the synthesis & secretion of T3 and T4 from thyroid gland
    Metabolic rate stimulated
    Thyroid Stimulating Hormone (TSH)
  23. What releases Follicle Stimulating Hormone?
  24. 1. initiates the formation of follicles within the ovary
    2. stimulates follicle cells to secrete estrogen
    3. stimulates sperm production in testes
    FSH functions
  25. Produces Luteinizing Hormone (LH)
  26. What hormone stimulates this in females:
    -Secretion of estrogen
    -Ovulation of 2nd oocyte
    -Formation of corpus luteum
    -Secretion of progesterone
    Luteinizing Hormone (LH)
  27. In males, stimulates interstitial cells to secrete testosterone
    Luteinizing Hormone (LH)
  28. Produce prolactin
  29. Causes milk production
    Function in males not known
    Prolactin (PRL)
  30. Secrete adrenocorticotrophichormone (ACTH)
  31. Stimulates cells of the adrenal cortex that produce glucocorticoids
    ACTH (Adrenocorticotrophic Hormone)
  32. Secreted by corticotrophs
    Melanocyte-Stimulating Hormones
  33. Function not certain in humans (increase skin pigmentation in frogs)
    Melanocyte-Stimulating Hormones
  34. Does not synthesize hormones
    Posterior Pituitary Gland (Neurohypophysis)
  35. Consists of axon terminals of hypothalamic neurons
    Posterior Pituitary Gland (Neurohypophysis)
  36. Neurons release two neurotransmitters that enter capillaries
    – antidiuretic hormone
    – oxytocin
    Posterior Pituitary Gland (Neurohypophysis)
  37. Also known as vasopressin
    Antidiuretic Hormone (ADH)
  38. Functions (response to low BP)
    – decrease urine production
    – decrease sweating
    – increase BP
    – increased thirst
    Antidiuretic Hormone (ADH)
  39. Two target tissues both involved in neuroendocrine reflexes
  40. Which hormone?
    During delivery– baby’s head stretches cervix– hormone release enhances uterine muscle contraction– baby & placenta are delivered
  41. Which hormone?
    After delivery– suckling & hearing baby’s cry stimulates milk ejection– hormone causes muscle contraction & milk ejection
  42. On each side of trachea is lobe of thyroid gland joined by isthmus
    Thyroid Gland
  43. Consists of follicular cells surrounding follicle filled with precursor substance (thyroglobulin), active form is called thyroid hormone, T3 or T4
    Thyroid Gland
  44. What are the 3 Thyroid hormone functions?
    • Regulate oxygen use and metabolic rate
    • Cellular metabolism
    • Growth and development
  45. Histology of Thyroid Gland:
    Sac of stored hormone (colloid) surrounded by follicular cells that produced it
  46. Histology of Thyroid Gland:
    In between cells
    Parafollicular cells
  47. Produce calcitonin
    Decreases blood calcium levels by decreasing activity of osteoclasts and excretion by kidneys
    Parafollicular cells
  48. Oxyphil cell function:
  49. What do Principal cells produce?
    Parathyroid hormone (PTH)
  50. Increase activity of osteoclasts
    Increases reabsorption of Ca+2 by kidney
    Promote formation of calcitriol (vitamin D) by kidney and liver which increases absorption of Ca+2 by intestinal tract
    Raise blood calcium levels (Parathyroid hormone)
  51. Opposite function of calcitonin
    Parathyroid Hormone
  52. One on top of each kidney
    Adrenal Glands
  53. Which cortex produces 3 different types of hormones from 3 zones of cortex?
    Adrenal Glands
  54. Which medulla produces epinephrine & norepinephrine?
    Adrenal Glands
  55. What are the 3 structural parts of the adrenal gland?
    • Capsule
    • Cortex
    • Medulla
  56. Secreted in response to low blood pressure, signals kidney to absorb more Na+ and water
    Mineralocorticoids (aldosterone)
  57. Secreted in response to stress, raises blood sugar levels also used as an anti-inflammatory agent (over use reduces immune response)
    Glucocorticoids (cortisol)
  58. Have masculinizing effects
  59. Adrenal Medulla:
    Receive direct innervation from sympathetic nervous system
    – develop from same tissue as postganglionic neurons
    Chromaffin cells
  60. Produce epinephrine & norepinephrine
    Adrenal Medulla
  61. Hormones are sympathomimetic
    – effects mimic those of sympathetic NS
    – cause fight-flight behavior
    Adrenal Medulla
  62. Organ consists of head, body & tail
  63. Which organ:
    Cells (99%) in acini produce digestive enzymes (exocrine part)
  64. Cells in pancreatic islets that produce hormones (islets of Langerhans)
    Endocrine cells
  65. Cells that surround a small duct in the pancreas
    Exocrine acinar cells
  66. Cell organization in pancreas:
    Cells that secrete near a capillary
    Endocrine cells
  67. Cell Types in the Pancreatic Islets:
    Produce glucagon (increases blood sugar levels)
    Alpha cells (20%)
  68. Cell Types in the Pancreatic Islets:
    Produce insulin (decreases blood sugar levels)
    Beta cells (70%)
  69. Cell Types in the Pancreatic Islets:
    Produce somatostatin (reduces secretions of alpha and beta cells)
    Delta cells (5%)
  70. Cell Types in the Pancreatic Islet:
    Produce pancreatic polypeptide (inhibits activity of exocrine part of pancreas)
    F cells
  71. Estrogen, progesterone, relaxin & inhibin
    Regulate reproductive cycle, maintain pregnancy & prepare mammary glands for lactation
  72. Interstitial cells produce testosterone
    Regulate sperm production & 2nd sexual characteristics
  73. Small gland attached to 3rd ventricle of brain
    Consists of pinealocytes & neuroglia
    Pineal Gland
  74. Pineal Gland:
    Responsible for setting of biological clock
  75. Pineal Gland:
    Treatment is bright light
    Jet lag & SAD
  76. Pineal Gland:
    Hyperactive person (high sympathetic activity)
  77. Effect of Light on Pineal Gland:
    _________secretion producing sleepiness occurs during darkness due to lack of stimulation from sympathetic ganglion
    • Melatonin
    • (darkness inhibits melatonin release)
  78. Depression that occurs during winter months when day length is short
    Due to overproduction of melatonin
    Seasonal Affective Disorder
  79. Due to overproduction of melatonin
    Jet Lag
  80. Therapy for SAD and Jet Lag
    exposure to several hours per day of artificial light as bright as sunlight
  81. Important role in maturation of T cells in infants and children
    Hormones produced by gland promote the proliferation & maturation of T cells
    Thymus Gland
  82. 4 hormones produced by thymus gland:
    • Thymosin
    • Thymic humoral factor
    • Thymic factor
    • Thymopoietin
Card Set
Endocrine System