1. The Endocrine System
Chapter 18

2. General Characteristics
includes cells, tissues, and organs that secrete hormones directly into the body fluids to help regulate metabolic processes such as chemical reactions, reproduction, growth, and development
The 9 Endocrine glands include the 1. pituitary (anterior and posterior), 2. thyroid, 3. parathyroid, 4. adrenal, 5. pineal, 6. thymus, 7. pancreas, 8. testes, and 9. ovaries

4. Hormones
biochemicals secreted by a cell that affect the function of another cell
3 types:
Steroid – derived from cholesterol (fat)
Peptide – an amino acid based hormone (protein)
Prostaglandins – hormone-like lipids (fat); act more locally than hormones; only affect organ where produced
Hormones are released based on the body’s need and are carried by the blood to the target cell; controlled by negative feedback

5. Hormones of Anterior Pituitary
Target tissue
Effects
Adreno - corticotropic hormone (ACTH)
Adrenal glands
Stimulates production of steroid hormones
Follicle- stimulating hormone (FSH)
Ovaries and testes
Regulates development of male/female gametes Regulates development of male/female gametes and production of testosterone in testes of males
Luteinizing hormone (LH)
Stimulates release of egg from ovary; stimulates production of testosterone

6. Hormones of Anterior Pituitary (cont).
Target tissue
Effects
Prolactin
Mammary glands
Stimulates milk production in breasts
Growth hormone or somatotropin (GH)
All tissues
stimulates cell growth and division, particularly bone and muscle

7. Hormones of Posterior Pituitary
Target tissue
Effects
Antidiuretic hormone (ADH)
Kidneys, blood vessels
Stimulates absorption of water (less urine production) and thereby regulates water balance
Oxytocin
Mammary glands, uterus
Stimulates uterine contractions, onset of labor, and the letting down of milk to the breasts.

10. Hormones of Adrenal Glands
Target tissue
Effects
Aldosterone
Kidneys
Maintains blood volume and pressure (stimulates kidneys to conserve sodium, and therefore retain water)
Cortisol
All tissues
Controls inflammation, increases blood glucose concentration, suppresses immune response
Epinephrine and norepinephrine
Skeletal and cardiac muscle, blood vessels
Initiates response to stress; increases metabolic rate, heart rate, blood pressure; dilates blood vessels; raises blood glucose levels

12. Hormones of Pancreas Hormone Target tissue Effects Insulin All tissues
Stimulates conversion of glucose to glycogen; lowers blood glucose levels
Glucagon
Liver, fatty tissues
Stimulates conversion of glycogen to glucose; raises blood glucose levels

14. Hormones of Pineal Gland
Target tissue
Effects
Melatonin
Uncertain, possibly testes and ovaries
May regulate biorhythms and moods; may control onset of puberty

16. Hormones of Thyroid Gland
Target tissue
Effects
Calcitonin
Bone tissue
Inhibits release of calcium from bone; lowers blood calcium levels (opposite of parathyroid hormone)
Thyroxine
All tissues
Raises metabolic rate; necessary for normal growth

18. Hormones of Ovaries Hormone Target tissue Effects Estrogen
All tissues, female reproductive structures
Controls dev. of secondary sex charac. and sex organs; initiates preparation of uterus for pregnancy
Progesterone
Uterus, breasts
Completes preparation of uterus for pregnancy; stimulates breast dev.

20. Hormones of Testes Hormone Target tissue Effects Testosterone
All tissues, male reproductive organs
Controls dev. of secondary sex charac. and sex organs; stimulates sperm formation

22. Hormones of Parathyroid Gland
Target tissue
Effects
Parathyroid hormone (PTH)
Bone tissue, kidneys
Stimulates breakdown of bone and release of calcium into bloodstream; raises blood calcium levels

24. Hormones of Thymus Gland
Target tissue
Effects
Thymosin
Bone Marrow
Altered in spleen
Regulates production of white blood cells (immunity)

26. Disorders - Pituitary Gland
Diabetes insipidus – deficiency of ADH; characterized by large volumes of dilute urine and constant thirst; usually caused by an injury to the head, complications with brain surgery, or a brain tumor; can be genetic

27. Disorders - Pituitary Gland (dwarfism)
Pituitary Dwarfism – any person who is under 4’ 10” tall is considered a dwarf. Is caused by a deficiency of HGH in adolescence; limbs proportional and normal mental development; but may not develop adult sex features. 10,000 to 15,000 in U.S.
Achondroplasia - is the most common type of dwarfism. It is characterized by abnormal body proportions. Affected individuals have arms and legs that are very short, while the torso is nearly normal size. Caused by mutation on chromosome 3 effects cartilage formation. 80% of dwarves

28. Achondroplasia

29. Disorders - Pituitary Gland (gigantism)
Gigantism – overproduction of HGH in adolescence; height may exceed 8 ft; rare, usually result of tumor (or small tumors); other hormones of pituitary gland usually affected so other hormone-related problems. Top 1% in height.
Acromegaly – overproduction of HGH after puberty and growth plates have fused can cause type 2 diabetes, high blood pressure, increased risk of cardiovascular disease, and arthritis.

30. 12 yr old boy with mother
8 ft 11 inches

31. Disorders - Pancreas
Diabetes mellitus – insulin deficiency; inhibits conversion of glucose to glycogen therefore blood sugar is too high; results in excess urine output; also, cells use protein for energy instead of sugar so body tissues waste away; results are weight loss, hunger, fatigue, dehydration
Type I – juvenile – autoimmune disease; immune system attacks cells that synthesize insulin; treatment – insulin injections
Type II – adult – usually appears after age 40; usually in overweight adults; body cells lose sensitivity to insulin; treatment – controlling diet, exercise, maintaining healthy body weight

32. Diabetes
Hypoglycemia – low blood sugar (can cause diabetic coma). No energy
Hyperglycemia – high blood sugar (can cause the rupture of blood vessels, blurred vision, thirst, hunger, and frequent urination.
Gestational Diabetes – Diabetes during pregnancy caused by high level of production of FSH and LH which blocks the effectiveness. Typically not a problem after pregnancy and does not usually cause birth defects like normal diabetes if managed correctly.

33. Disorders - Thyroid
Graves’ disease (hyperthyroidism) – elevated metabolic rate; restlessness; overeating; eyes protrude b/c of swelling in the tissues behind them; thyroid gland enlarges causes swelling in neck called a goiter
Hypothyroidism – in infants called Cretinism – stunted growth, abnormal bone formation; mental retardation; low body temp; sluggishness; in adults called Myxedema – lethargy; hair loss; low metabolic rate; obesity; more common in females

34. Goiter

35. Disorders – Adrenal gland
Cushing’s syndrome – hypersecretion of cortisol; alters carb and protein metabolism and electrolyte balances; upper body obesity; rounded face; increased fat around neck; thinning arms and legs
Addison’s disease – hyposecretion of cortisol and aldosterone; weight loss; dehydration; muscle weakness; fatigue; low blood pressure; darkening of skin; JFK had this disease

36. Cushings syndrome
Same patient 2 yrs later after treatment

37. Disorders – Parathyroid
Kidney stones – too much PTH; stimulates osteoclast activity; bones soften, deform; excess calcium in body fluids results in abnormal storage of calciumkidney stones