Endocrine System

• Endocrine system


  A complex network of glands and organs that produces hormones, regulating physiological processes
• Types of glands


  • Exocrine glands
  • Endocrine glands
• Exocrine glands


  Releases substances through a duct or opening to a body
• Endocrine glands


  Produces hormones and releases it directly into the bloodstream
• Hormones


  Chemical messengers that travel to organs and tissues to carry out functions
• Hormones target organs


  Carry out functions
• Pituitary gland


  Controls the functions of other endocrine glands, also known as Master Gland
• Hypothalamus


  Signals the anterior and posterior pituitary gland when to release hormones
• Pituitary gland regions


  • Anterior
  • Posterior
• Anterior pituitary


  • Releases its own hormones
• Posterior pituitary

  • Stores and releases hormones made by hypothalamus
• Growth hormone

  Increase tissue growth, increase metabolism
• Thyroid-stimulating hormone

  Increase production of thyroid hormones
• Adrenocorticotropic hormone


  Produces the stress hormone (cortisol)
• Prolactin


  Breast milk production
• Oxytocin


  Childbirth, breast feeding, increase uterine contraction
• Antidioretic hormone


  Increases water reabsorption
• Thyroid gland


  Produces thyroxine (T4), converted to triiodothyronine (T3) which regulates metabolism
• Calcitonin


  Decrease blood calcium levels
• Adrenal medulla


  Produces adrenaline, rapid source of energy
• Adrenal cortex


  Produces cortisol, release of glucose
• Sex hormones


  Develop primary and secondary sexual characteristics
• Ovary


  Produces androgen and estrogen
• Testes


  Produce testosterone
• Pineal gland


  Produces melatonin, the sleep hormone
• Pancreas


  Produces glucagon (raises blood sugar) and insulin (lowers blood sugar)
• Diabetes mellitus


  Occurs when the pancreas produces too little or no insulin, or the body is resistant to insulin
• Types of diabetes


  • Type 1 (pancreas produces little or no insulin)
  • Type 2 (body is resistant to insulin)
• Prevalence of diabetes in adults is 7.5%
• Treatments for diabetes


  • Insulin injection
  • Pancreas transplant (type 1)
  • Oral diabetes medication or insulin (type 2)
• Negative feedback


  Inhibits or stimulates hormone production to maintain optimal levels, e.g. regulating blood sugar
• Positive feedback


  Triggers excessive increase or decrease in hormone production, e.g. regulating body temperature
• Anterior

  • Growth Hormone
  • Thyroid-Stimulating Hormone
  • Adreno-Corticotrophic Hormone
  • Prolactin