Chapter 16: The Endocrine System

  1. Endocrinology
    study of hormones and endocrine organs
  2. Endocrine System
    • Controls and integrates:
    • Reproduction
    • Growth and Development
    • Balance of Blood
    • Regulation of cellular metabolism
    • Mobilization of body defenses
  3. Exocrine glands
    • nonhormonal substances - sweat, saliva
    • have ducts
  4. Endocrine glands
    • Produce hormones
    • Lack ducts
  5. Hormones
    • long-distance chemical signals
    • through blood or lymph
  6. Autocrines
    • chemicals that exert effects on same cells that secrete them
    • local chemical messenger: not endocrine system
  7. Paracrines
    • locally acting chemicals that affect cells other than those that secrete them
    • local chemical messenger: not endocrine system
  8. Amino acid-based hormones
    amino acid derivatives, peptides, and proteins
  9. Steroids
    • Synthesized from cholesterol
    • Gonadal and adrenocortical hormones
  10. Target Cells
    cells with receptors for that hormone
  11. Water-soluble hormones
    • all amino acid-based hormones except thyroid hormone
    • Cannot enter cell
    • Act on plasma membrane receptors
  12. Lipid-soluble hormones
    • Steroid and thyroid hormones
    • Can enter cell
    • Act on intracellular receptors that directly activate genes
  13. Hormone Release
    • Controlled by negative feedback systems
    • In response to humoral, neural, and hormonal stimuli
  14. Nervous System Modulation
    Nervous system can override normal endocrine controls
  15. Thyroid
    • located in the throat
    • bilobed gland connected by an isthmus
  16. Adrenal Gland
    found close to the kidney
  17. Pancreas
    a mixed gland, located close to the stomach and small intestine
  18. Testes
    paired glands suspended in the scrotum
  19. Parathyroid
    ride "horseback" on the thyroid gland
  20. Ovary
    • found in pelvic cavity of the female
    • concerned with ova and female hormone production
  21. Thymus
    • found in the upper thorax overlying the heart
    • large during youth
  22. Pineal Gland
    found in roof of the third ventricle
  23. Growth Hormone
    • Pituitary Gland (anterior)
    • Throughout the Body
    • Stimulates growth and development
    • excessive amounts lead to large features
    • inadequate amounts lead to small stature
  24. Follicle-stimulating hormone
    • Pituitary Gland (anterior)
    • Sex Glands
    • Stimulates female egg maturation and male sperm production
  25. Luteinizing hormone
    • Pituitary gland (anterior)
    • Sex glands
    • Stimulates female ovulation and male secretion of testosterone
  26. Thyroid-Stimulating hormone
    • Pituitary gland (anterior)
    • Thyroid Gland
    • Triggers secretion of thyroid hormones
  27. Antidiuretic Hormone
    • Pituitary Gland (posterior)
    • Kidney
    • Regulates water retention and blood pressure
  28. Oxytocin
    • Pituitary gland (posterior)
    • Uterus / Mammary glands
    • Triggers contraction of the uterus during labor / Stimulates milk letdown for breast-feeding after childbirth
  29. Melatonin
    • Pineal gland
    • Unclear, althought possible target sites are pigment cells and sex cells
    • May affect skin pigmentation; may regulate biorhythms (awake/sleep patterns) and prevent jet lag
  30. Calcitonin
    • Thyroid gland
    • Bones
    • Controls the level of calcium in the blood by depositing it in the bones
  31. Thyroid hormone (T3/T4)
    • Thyroid gland
    • Throughout body
    • Increases the body's metabolic rate; promotes normal growth and development
  32. Parathyroid hormone
    • Parathyroid glands
    • Bones, intestines, and kidneys
    • Regulates calcium in blood
  33. Epinephrine
    • Adrenal gland
    • Muscles and blood vessels
    • Increases blood pressure, heart and metabolic rate, and blood sugar levels,; dilates blood vessels - also released during exercise
  34. Norepinephrine
    • Adrenal gland
    • Muscles and blood vessels
    • Increases blood pressure and heart rate - constricts blood vessels
  35. Glucagon
    • Pancreas
    • Liver
    • Stimulates the breakdown of glycogen (stored carbohydrate) into glucose (blood sugar) - regulates glucose blood level
  36. Insulin
    • Pancreas
    • Throughout body
    • Regulates blood glucose levels - increase storage of glycogen - facilitates glucose intake by body cells
  37. Estrogen
    • Ovaries
    • Female reproductive system
    • Causes sexual development and growth - maintains proper functioning of female reproductive system
  38. Testosterone
    • Testes
    • Throughout body
    • Causes sexual development and growth spurt - maintains proper functioning of male reproductive system
  39. Erythropoietin
    • Kidney
    • Bone marrow
    • Produces red blood cells
Card Set
Chapter 16: The Endocrine System
endocrine system