1. The endocrine system

2. What is an endocrine gland?
Endocrine: secretes substance into blood
Exocrine: secretes substance into a duct (ex: sweat)

3. ENDOCRINE GLANDS
PITUITARY GLAND

4. a. Growth Hormone (GH)
Hypersecretion = gigantism (children) or acromegaly (adults)

5. Stimulates milk production after childbirth
b. Prolactin (PRL)
Stimulates milk production after childbirth
c. Adrenocorticotropic hormone (ACTH)
Tropic hormone
Stimulates cortex of
adrenal gland

6. Hormones of adrenal cortex (corticosteroids)
1. Mineral corticoids – regulate mineral content of blood, like sodium and potassium
Glucocorticoids – regulate metabolism and resistance to stress
Ex: cortisone
Androgens (sex hormone)
In puberty: stimulate axillary/pubic hair growth/growth spurt
Insignificant effect in males after puberty
In females: libido and converted into estrogens 6

7. d. Thyroid-stimulating hormone (TSH)
Tropic hormone
Growth & activity of thyroid gland:
1. Calcitonin (not influenced by TSH)
Decreases blood calcium levels by causing calcium to be deposited in the bones.
Stimulus?
Target?
2. Thyroid hormone
Controls rate at which glucose is “burned” (oxidized)
Targets every cell

8. What is a tropic hormone?
A synthetic (“man-made”) hormone
Hormones that affect the gonads
Hormones of the thyroid gland
A hormone that triggers another endocrine gland to secrete its hormones

9. e. Gonadotropic hormones - tropic hormones
a. function: regulate activity of gonads
b. types:
1. Follicle-stimulating hormone (FSH): egg/sperm development
2. Luteinizing hormone (LH): sex hormone synthesis; ovulation

10. f. Oxytocin- causes contractions for birth
g. Antidiuretic hormone (ADH)
Diuresis = urine production
causes kidneys to reabsorb water from the forming urine
stimulus?
caffeine inhibits ADH secretion

11. Which of the following is NOT a hormone secreted by the pituitary gland?
Prolactin
Adrenocorticotropic hormone
Growth hormone
Calcitonin

12. What does sterility mean?
What effect would LH and FSH have on this?

13. summary Pituitary gland – considered the “master” gland
We covered 7 hormones it produces
Extra credit assignment: write a story about a character that does not have a pituitary gland. Due: by the 11th (Monday)

14. 2. PARATHYROID GLAND
POSTERIOR OF THYROID

15. 2. PARATHYROID GLAND Found posterior side of thyroid
Parathyroid hormone (PTH)
Regulator of calcium homeostasis in blood.
Responds to LOW levels of Ca2+
targets the skeleton
Hyposecretion: muscles uncontrollably spasm  fatal
Hypersecretion: massive bone destruction

16. ADRENAL GLANDS: SUPERIOR TO KIDNEYS

17. Hormones of adrenal cortex (corticosteroids)
SKIP
Hormones of adrenal cortex (corticosteroids)
1. Mineral corticoids – regulate mineral content of blood, like sodium and potassium
Ex: aldosterones
Glucocorticoids – regulate metabolism and resistance to stress
Ex: cortisone
Androgens (sex hormone)
In puberty: stimulate axillary/pubic hair growth/growth spurt
Insignificant effect in males after puberty
In females: libido and converted into estrogens

18. Problems with adrenal cortex
Hyposecretion  Addison’s disease, fatal without treatment
Weight loss
Muscle weakness
Fatigue that gets worse over time
Low blood pressure
Patchy or dark skin
Hypersecretion of glucocorticoids  Cushing’s syndrome, fatal without treatment
Weight gain, particularly around your midsection and upper back
Fatigue
Rounding of your face (moon face)
Fatty pad or hump between your shoulders (buffalo hump)
Pink or purple stretch marks (striae) on the skin
High blood pressure, diabetes, bone loss
SKIP

19. Adrenal cortex – see pituitary notes

20. adrenal medulla a. Epinephrine b. Norepinephrine
Augments fight-or-flight

21. 4. PANCREAS

22. a. Insulin – Responds to rising blood glucose levels
Hyposecretion high blood glucose levels …. Diabetes mellitus (classic symptoms: polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger)
Type I – failure to make insulin
Type 2 – insulin resistance
Gestational – during pregnancy

23. b. Glucagon
responds to low blood glucose levels.
target: liver

25. 5. PINEAL GLAND

26. a. Melatonin- regulates day-night cycles

27. Copyright 1997 Smithsonian Magazine All rights reserved.
                                                                                       
                                                   
Taken on a strict schedule, melatonin can help reduce jet lag. (But was that West Coast or London time?)
Copyright 1997 Smithsonian Magazine All rights reserved.

28. 6. THYMUS
Produces thymosin – regulates maturation of some white blood cells; important for immune system

29. 7. GONADS 7A) OVARIES 1. Estrogens –
stimulate secondary sex characteristics in females
brings about menstrual cycle

30. Hyposecretion of either: infertility
Progesterone-
brings about menstrual cycle.
quiets muscles of uterus during pregnancy
Hyposecretion of either: infertility

31. 7b) Testes 1. Testosterone testes
cause growth and maturation of reproductive system
secondary sex characteristics; sperm production in adult
Hyposecretion = infertility

33. 8. PLACENTA (Temporary organ)
human chorionic gonadotropin (hCG) – stimulates ovary to continue producing estrogen and progesterone
Estrogen & progesterone (3rd month)
Relaxin – relaxes pelvis

34. Aging and the endocrine glands
Late middle age: efficiency of ovaries begins to decline  menopause
GH declines = muscles atrophy
Mildly hypothyroid
Less able to resist stress/infection (due to thymus, glucocorticoids of adrenal and melatonin from pineal)
Some decline in insulin production  diabetes
(not responsible for this slide)

35. How hormones work 2 categories of hormones Soluble in lipids
Most attached to transport protein in blood
Ex: Thyroid hormone, sex hormones
Soluble in water
Travel by themselves in blood
Ex: epinephrine/norepinephrine, ADH, oxytocin, GH, insulin

36. Lipid-soluble hormones: stimulate synthesis of new proteins
Diffuse through lipid bilayer (cell membrane)
Binds to receptors in cytoplasm or nucleus
Triggers gene on/off  synthesis of new protein that alters the cell’s activity

37. MECHANISM OF ACTION OF LIPID-SOLUBLE HORMONES
VIDEO CLIP

38. Water-soluble hormones: modify existing proteins
Binds to receptor on cell membrane
Activates G protein (membrane protein) that eventually causes ATP to convert to cyclic AMP (the second messenger).
Cyclic AMP activates one/more protein kinases (enzyme that adds a phosphate group – phosphorylates – to other cellular proteins).
Phosphorylated proteins cause physiological response
Enzyme phosphodiesterase inactivates AMP

39. Water-soluble hormone action

40. Water-soluble hormone action