Endocrine System: Glands and Hormones

• The body produces 50 different hormones that regulate everything in the body
• Hormones regulate functions such as sleep, hunger, mood, reproduction, and metabolism
• Hormones work to keep the body balanced, also known as homeostasis
• Major endocrine glands in the body:

  • Hypothalamus
  • Pituitary gland
  • Pineal gland
  • Thyroid and parathyroid glands
  • Adrenal glands
  • Pancreas
  • Gonads: testes in males and ovaries in females
• The hypothalamus, pituitary gland, and pineal gland are located in the brain
• The thyroid and parathyroid glands are near the neck
• The adrenal glands are on top of the kidneys
• The pancreas is nestled behind the stomach
• The gonads are testes in males and ovaries in females
• Anterior pituitary hormones:

  • Growth hormone (GH)
  • Prolactin
  • Thyroid-stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Follicle Stimulating Hormone (FSH)
  • Luteinizing hormone (LH)
• Growth hormone affects the growth of organs, especially bones and cartilage
• Prolactin is responsible for lactation and breast development in females
• TSH stimulates the thyroid gland to produce thyroid hormone
• ACTH stimulates the adrenal glands to produce critical hormones
• FSH and LH are involved in sexual development and reproduction in both males and females
• Posterior pituitary hormones:

  • Antidiuretic hormone or vasopressin
  • Oxytocin
• Vasopressin helps control blood pressure by balancing salt and water levels
• Oxytocin is involved in childbirth and is known as the love hormone
• Thyroid gland:

  • Produces Thyroxine (T4) and Triiodothyronine (T3)
  • Regulates basal metabolism
  • Requires iodine from the diet for hormone production
• Thyroxine increases overall basal metabolism
• Calcitonin regulates calcium levels by decreasing blood calcium levels
• Parathyroid glands:

  • Produce parathyroid hormone
  • Regulate calcium levels by increasing blood calcium levels
• Calcium is important for bone health, muscle contraction, and blood clotting
• Pancreas:

  • Regulates blood glucose levels
  • Produces insulin and glucagon
• Insulin decreases blood glucose levels by allowing cells to take in glucose
• Glucagon increases blood glucose levels by releasing stored glucose from the liver
• Adrenal glands:

  • Adrenal cortex secretes glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone)
  • Adrenal medulla secretes adrenaline/epinephrine and noradrenaline/norepinephrine
• Cortisol regulates metabolism, cell division, inflammation, and immune function
• Aldosterone regulates mineral levels affecting blood pressure and metabolic reactions
• Adrenaline and noradrenaline initiate the fight-or-flight response
• Gonads:

  • Testes in males and ovaries in females
  • Produce estrogen, progesterone, and testosterone
• Sex hormones control menstrual cycle in females and sperm production in males
• FSH and LH regulate sex hormone production from the gonads
• Hormones affect growth and development during puberty in both males and females
• Estrogen, progesterone, and testosterone are present in all individuals, with varying levels
• Hormones interact with each other and with other body systems to maintain balance