Endocrine System

• Pineal Gland:

  • Located on the roof of the 3rd ventricle of the brain
  • Produces melatonin, regulating the body's biological clock
• Pituitary Gland:

  • Divided into 2 lobes: Anterior Pituitary Gland (Adenohypophysis) and Posterior Pituitary Gland (Neurohypophysis)
  • Anterior Pituitary Gland's origin is the Pharyngeal Episternum and is controlled by Hypothalamic releasing inhibitory Hormones
  • Produces 7 hormones including Prolactin, Growth Hormone, TSH, MSH, ACTH, FSH, and Luteinizing Hormones
• Anterior Pituitary Gland Hormones:

  • Prolactin: production of milk, increased levels lead to amenorrhea in females and erectile dysfunction in males
  • Growth Hormone: stimulates growth of soft tissue and long bones, abnormalities in levels lead to Acromegaly, Gigantism, or Dwarfism
  • TSH: stimulates the release of thyroid hormones
  • MSH: stimulates skin pigmentation release
  • ACTH: stimulates cortisol release
  • FSH: in females stimulates estrogen and progesterone, in males stimulates sperm production
  • Luteinizing Hormones: in females triggers ovulation, in males stimulates testosterone production
• Posterior Pituitary Gland:

  • Controlled by the Hypothalamus
  • Stores and releases hormones like Oxytocin for milk ejection and uterine wall contractions, and ADH (Vasopressin) for water reabsorption in the kidneys
• Thyroid Gland:

  • Located inferior to the larynx
  • Produces Thyroid Hormones (T3 and T4) for CNS development, with abnormalities leading to Cretinism or Myxedema
  • Also produces Calcitonin to decrease blood calcium levels
• Parathyroid Gland:

  • Located on the posterior surface of the lateral lobe of the thyroid gland
  • Produces Parathormone (Parathyrine) to increase calcium levels in the blood
• Thymus Gland:

  • Located behind the sternum between the 2 lungs
  • Produces Thymosin for the maturation of T-cells, aiding in virus destruction
• Adrenal Gland:

  • Located superior to each kidney
  • Adrenal Cortex has 3 zones: Zona Glomerulosa (produces Aldosterone), Zona Fasciculata (produces Cortisol), and Zona Reticulata (produces Androgen)
  • Adrenal Medulla produces Epinephrine and Norepinephrine for the fight or flight response
• Pancreas:

  • Contains Islet of Langerhans
  • Produces hormones like Glucagon, Insulin, and Somatostatin to regulate blood sugar levels