Endocrine system and the 7 major glads in the body

• Endocrine System


  Composed of glands that secrete different types of hormones affecting almost every cell, organ, and function of the body. Regulates growth, development, metabolism, reproductive processes, and mood
• Types of Glands

  • Endocrine - releases substances directly into the bloodstream
  • Exocrine - releases substances into a duct or opening to the inside or outside of the body
• Major Glands in the Body

  • Pituitary
  • Thyroid
  • Parathyroid
  • Thymus
  • Adrenal
  • Pancreas
  • Reproductive (Testes - Males, Ovaries - Females)
• Hormones

  Chemical messengers secreted directly into the blood, carried to organs and tissues to exert their functions
• Thyroid Gland


  • Regulates Metabolism
  • Composed of two lobes connected by an isthmus
  • Secretes thyroxin regulating growth and development
  • Enlargement leads to Goiter
• Parathyroid Gland

  • Regulates Calcium Levels
  • Secretes parathormones (PTH) maintaining calcium and phosphorus ratio
  • Located on the dorsal surface of the thyroid
• Thyroxine


  Stimulates metabolic rate for growth, increases oxygen consumption and cell metabolism
• Calcitonin


  Regulates Ca+ levels in the blood, decreases concentration
• Adrenal Glands

  • Glucocorticoids raise glucose levels, stimulate glucose production
  • Epinephrine gives an energetic boost, increases metabolic rate, dilates bronchioles, increases heart rate
• Epinephrine


  Complements supply from the sympathetic system, functions to give the body an energetic boost, increase metabolic rate, dilate bronchioles, increase heart rate
• Hypothalamus


  A small gland about 1.0 cm in diameter located at the base of the brain that controls the pituitary gland
• Diabetes

  Type II - due to aging, lifestyle, heredity and other lifestyle (diet) factors decreased responsiveness by cells of target organs to insulin
• Thymus

  Secretes thymosin that controls metabolic rate and is involved in the formation of white blood cells
• Pancreas


  Glucagon increases blood sugar levels (secreted by alpha cells)
• Adrenal glands

  Two small masses located above the kidneys that secrete epinephrine and nor-epinephrine, promoting flight or fight reactions during emergency
• Diabetes

  Type I-autoimmune disorder (destroys ability to produce insulin)
• Hypothalamus


  Secretes releasing hormones that travel via a portal system and stimulate the anterior pituitary
• Pancreas


  Insulin lowers blood sugar levels (secreted by beta cells)
• Thymus


  Stimulates T cell development (Immune Response)
• Temporary organ

  Reaches greatest development at age 14 to 16
• Insulin


  Target organs - liver, skeletal, adipose (fat) tissues
• Adrenal medulla

  Secretes epinephrine and nor-epinephrine
• The pituitary gland makes, stores and releases hormones. The pituitary gland is located at the base of your brain, below your hypothalamus.