Endocrine System II

• The nervous system coordinates and regulates all communications and processes within the body
• The nervous system helps us adapt to changes in the environment to survive
• The nervous system works with the endocrine system to coordinate and direct the activity of the body's cells
• The endocrine system provides slower but longer-lasting coordination compared to the nervous system
• The endocrine system acts through chemical messengers called hormones
• Hormones released by endocrine glands influence bodily functions such as respiration, metabolism, reproduction, movement, sensory perception, sexual development, and growth
• Endocrine glands are ductless glands that release hormones directly into the bloodstream
• The main hormone-producing glands of the endocrine system include:

  • Hypothalamus
  • Pituitary gland
  • Pineal gland
  • Thyroid gland
  • Parathyroid glands
  • Thymus
  • Pancreas
  • Adrenal glands
  • Ovaries (female gonads)
  • Testes (male gonads)
• Hypothalamus:

  • Responsible for body temperature, hunger, moods, and hormone release from other glands
  • Produces hormones such as corticotropin releasing hormone (CRH), thyrotropin releasing hormone (TRH), gonadotropin releasing hormone (GnRH), oxytocin, vasopressin, and somatostatin
• Pituitary gland:

  • Controls the activity of most other hormone-secreting glands
  • Produces hormones such as growth hormone, prolactin, thyrotropin, corticotropin, antidiuretic hormone (vasopressin), and oxytocin
• Pineal gland:

  • Located in the middle of the brain
  • Secretes the hormone melatonin, which helps regulate sleep-wake cycles
• Thyroid gland:

  • Located in the front part of the lower neck
  • Produces thyroid hormones (T3 and T4) that affect every cell and organ in the body
  • Regulates metabolism, heart rate, body temperature, digestion, muscle contraction, and cell replacement
  • Produces calcitonin to regulate calcium levels in the blood
• Parathyroid glands:

  • Four tiny glands attached to the thyroid gland
  • Release parathyroid hormone to control calcium levels in the blood
• Thymus:

  • Located below the breastbone
  • Produces hormones like thymopoietin and thymosin that assist in immune response and T cell differentiation
• Pancreas:

  • Plays a role in digestion and blood sugar regulation
  • Produces insulin to lower blood glucose levels and promote glucose storage
  • Produces glucagon to prevent blood glucose levels from dropping too low
• Adrenal glands:

  • Two triangular glands on top of each kidney
  • Adrenal cortex produces corticosteroids that control salt balance, stress response, metabolism, and immune function
  • Adrenal medulla produces adrenaline (epinephrine) to increase blood pressure and heart rate during stress
• Reproductive glands:

  • Testes (male gonads) produce testosterone for physical development and maintenance of male reproductive system
  • Ovaries (female gonads) produce estrogen and progesterone for puberty, menstrual cycle regulation, and pregnancy
• Hormones are produced by glands and sent into the bloodstream to signal tissues on what to do
• Imbalances in hormone production can lead to diseases like diabetes, acromegaly, dwarfism, gigantism, and hyperthyroidism
• Endocrinologists are specialized doctors who treat hormone-related problems