1. Endocrine system
Chapter 45

3. Endocrine system Regulation & communication Blood system
Glands (ductless)
Hormones (chemicals)
Target tissues

4. (a) Endocrine signaling
Blood
vessel
Response

5. Nervous system Regulation & communication Nerves Axon
Neurotransmitters
Synapse

6. Both systems (overlap)
Neurohormone
Released by the nervous system
Into blood stream (ADH)
Norepinephrine
Chemical involved in both
Nervous system (cleft)
Endocrine system (adrenal gland)

7. Both systems Neural control of endocrine system Hypothalamus
Regulates hormonal secretion of the anterior pituitary
Glands derived from nervous tissue
Adrenal medulla, posterior pituitary & pineal gland

8. Local regulators Paracrine Messages between neighboring cells
1. Cytokines
Regulate immune system
2. Growth factors
Regulate cell growth
3. NO
Vasodilation (local blood vessels)

9. Local regulators 4. Prostaglandins 20-carbon fatty acid
Derived from lipids in plasma membrane
Found in many organs
Released into interstitial fluid

10. Local regulators 4. Prostaglandins A. Immune system
inflammation
B. Reproductive system
Labor
Semen
C. Digestive system
Inhibit gastric secretions
Increase gut motility

11. Local regulators D. Respiratory system E. Circulatory system
Some cause dilation
Some cause constriction
E. Circulatory system
Platelets
F. Urinary system
Renal vasodilation
Increased excretion

12. Hormone types 1. Polypeptide 2. Glycoprotein 3. Amines
Short, <100 aa, insulin, ADH
2. Glycoprotein
>100 aa, carbohydrate attached, FSH, LH
3. Amines
Tyrosine & tryptophan
Adrenal medulla (NE, Epinephrine)
Thyroid (T3 & T4
Pineal (Melatonin)

13. Hormone types 4. Steroids Lipids from cholesterol Testosterone
Estradiol, progesterone
Aldosterone, cortisol

14. Mechanism of regulation
1. Enter the cell
Lipophilic
Lipid soluble
2. Do not enter the cell
Lipophobic
Water soluble

15. Mechanism of regulation
1. Lipophilic (Steroids, thyroxine)
Not water soluble
Plasma attached to protein carriers
Target cell-release carrier
Cross plasma membrane
Bind receptor protein (+/- nucleus)
Hormone receptor binds DNA
Protein synthesis

16. Mechanism of regulation
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17. Mechanism of regulation
2. Lipophobic or too large
Bind receptors on target cell membrane
A. Triggers second-messenger system
cAMP
IP3/Ca+2
B. Causes change in an ion channel

18. Mechanism of regulation
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19. Mechanism of regulation

20. Mechanism of regulation

21. Mechanism of regulation

23. Thyroid Neck 2 lobes/isthmus T4 (tetraiodothyronine) thyroxine
T3 (triiodothyronine)
Regulates metabolism in the body
Calcitonin
Stimulates Ca2+ uptake into bones
Decreases serum Ca+2

24. Thyroid

25. Parathyroid glands Neck 4 small glands on top of thyroid
PTH (parathyroid hormone)
Increase in blood calcium levels
Stimulates osteoclasts
Break down calcium phosphate crystals
Stimulates kidneys to reabsorb Ca2+
Activates Vitamin D

26. Parathyroid glands

27. Pancreas Abdomen behind stomach Islets of Langerhans Insulin ( cells)
Decreases blood glucose levels
Stores in glycogen (liver/muscle) & fat (adipose cells)
Glucagon ( cells)
Increases glucose blood levels

28. Pancreas

30. Ovaries Abdomen Estrogen Secondary female characteristics Menstruation
Progesterone
Prepares/maintains pregnancy

31. Testes
Inguinal region
Testosterone
Maintain male characteristics

32. Ovaries and Testes

33. Steroids

34. Adrenal glands Small glands on top of kidneys 1. Adrenal cortex
Outer layer
2. Adrenal medulla
Inner layer

35. Adrenal glands Adrenal cortex A. Corticosteriods
Cortisol (glucocorticoid)
Increases serum levels of glucose
Gluconeogenesis
Converts aa to glucose
Exercise or fasting

36. Adrenal glands B. Mineralcorticoids Aldosterone
Stimulates kidneys to reabsorb Na+1
Stimulates kidneys to eliminate K+1
C. Gonadocorticoids
Androgens
Sex characteristics

37. Adrenal glands Adrenal medulla Catacholamines
Epinephrine/norepinephrine
Increased heart rate, BP, glucose blood levels,
Dilation of bronchioles
Decreased blood flow to skin and gut

38. Adrenal glands

39. Pituitary gland (hypophysis)
In the brain
Hangs by a stalk from hypothalamus
1.Anterior
Adenohypophysis
Developed from epithelial tissue
2. Posterior
Neurohypophysis
Developed from the neural tissue
Nerve axons from hypothalamus end here

40. Pituitary gland

41. Anterior pituitary gland
All hormones stimulate growth in target organs
Tropins
A. GH (growth hormone)
Somatotropin
Stimulates muscle growth (bone)

42. Anterior pituitary gland
B. ACTH
Adrenocorticotropic hormone
Corticotropin
Stimulates adrenal cortex (cortisol)
C. TSH
Thyroid-stimulating hormone
Thyrotropin
Stimulates thryroid to produce thyroxine

43. Anterior pituitary gland
D. LH
Luteinizing hormone
Stimulates ovulation & lining of uterus
Stimulates testes to produce testosterone

44. Anterior pituitary gland
E. FSH
Follicle stimulating hormone
Stimulates the egg development
Development of sperm
F. Prolactin
Stimulates mammary glands to produce milk

45. LH, FSH

46. Anterior pituitary gland
G. MSH
Melanocyte-stimulating hormone
Causes darkening of skin in some fish, amphibians & reptiles

47. Posterior pituitary gland
A. ADH
Antidiuretic hormone (vasopressin)
Stimulates water retention in the kidneys
B. Oxytocin
Milk ejection from mammary glands
Stimulates uterine contractions in labor

48. Pituitary gland

50. Pineal gland Small mass of tissue located near center of brain
Synthesizes & secretes melatonin (modified aa)
Regulates functions related to day and night
Seasons

51. Cerebrum Thalamus Pineal gland Hypothalamus Cerebellum Pituitary gland
Spinal cord
Hypothalamus
Posterior
pituitary
Anterior
pituitary

52. Hypothalamus control Posterior pituitary (direct)
Stimulation in hypothalamus
Causes release of hormone from axon in pp
ADH released increased blood osmolality
Oxytocin released due to baby suckling

53. Mammary glands, uterine muscles
Hypothalamus
Hypothalamus
Neurosecretory cells of the hypothalamus
Axon
Posterior
pituitary
Anterior
pituitary
HORMONE
ADH
Oxytocin
TARGET
Kidney tubules
Mammary glands, uterine muscles

54. Hypothalamus control Controls release of AP hormones
Neurons in Hypothalamus secrete releasing or inhibiting hormones
Anterior Pituitary (negative feedback)

55. Hypothalamus

56. thyroid Pathway Example + Stimulus Cold Sensory neuron
Hypothalamus secretes thyrotropin-releasing hormone (TRH )
Neurosecretory cell
Blood vessel
Anterior pituitary secretes
thyroid-stimulating
hormone (TSH
or thyrotropin )

57. thyroid Pathway Example Stimulus Cold Sensory neuron –
Hypothalamus secretes thyrotropin-releasing hormone (TRH )
Neurosecretory cell
Blood vessel –
Anterior pituitary secretes thyroid-stimulating hormone (TSH or thyrotropin )
Negative feedback
Thyroid gland secretes thyroid hormone (T3 and T4 )
Target cells
Body tissues
Increased cellular metabolism
Response

58. Liver, bones, other tissues
Anterior pituitary
Tropic effects only: FSH LH TSH ACTH
Neurosecretory cells of the hypothalamus
Nontropic effects only: Prolactin MSH
Nontropic and tropic effects: GH
Hypothalamic releasing and inhibiting hormones
Portal vessels
Endocrine cells of the anterior pituitary
Posterior pituitary
Pituitary hormones
HORMONE
FSH and LH
TSH
ACTH
Prolactin
MSH GH
TARGET
Testes or ovaries
Thyroid
Adrenal cortex
Mammary glands
Melanocytes
Liver, bones, other tissues

59. Problems Thyroid Graves disease Over production of thyroxine Cretinism
To little thyroxine in children
Leads to delayed skeletal and mental growth

60. Hyperthyroidism

61. Negative feedback

62. Problems Diabetes mellitus Decreased insulin
Decreased response to insulin
Increased blood sugar

63. Diabetes

64. Problems Growth hormone (anterior pituitary)
Gigantism too much hormone
Pituitary dwarfism to little hormone
Acromegaly to much hormone after growth plates are fused

66. Acromegaly

67. Problems Addison’s disease Insufficiency in ACTH
Increased pigmentation of skin
Imbalance of electrolytes