Anatomy 1352: Unit 1, Chapter 15 - The Endocrine System

Introduction

• Importance of Chapter 15 in the textbook.
• Focus on medical terminology related to the endocrine system.

Key Medical Terminology

• Combining Forms:
  • Adeno: Gland
  • Adreno/Adrenal: Adrenal glands
  • Andro: Male (e.g., Androgens)
  • Calcio: Calcium (e.g., Hypercalcemia)
  • Crine: To secrete (e.g., Endocrine)
  • Astro: Female (e.g., Estrogens)
  • Gonad: Sex glands (ovaries/testes)
  • Homeo: The same (e.g., Homeostasis)
  • Iodo: Iodine
  • Cal: Potassium
  • Natro: Sodium
• Suffixes:
  • Crying: To secrete
  • Dipsia: Thirst (e.g., Polydipsia)
  • Pressin: To press down
  • Tropin: To stimulate (e.g., Tropic hormones)

Endocrine vs. Nervous System

• Nervous System: Uses neurotransmitters; regulates sensory input and motor output.
• Endocrine System: Uses hormones transported through the bloodstream to regulate body functions and maintain homeostasis.
• Endocrine Glands: Secrete hormones directly into the bloodstream; differ from exocrine glands (e.g., sweat glands).

Hormones

• Types of Hormones:
  • Lipid Soluble: Primarily steroids, derived from cholesterol (e.g., steroid hormones, thyroid hormones T3 and T4).
  • Water Soluble: Proteins or peptides; include prostaglandins, leukotrienes (involved in inflammation).
• Transport and Action:
  • Lipid Soluble Hormones: Require transport proteins; bind to receptors inside cells.
  • Water Soluble Hormones: Bind to cell surface receptors; involve second messengers like cyclic AMP.

Functions of Hormones

• Regulate fluid and electrolyte balance, metabolism, growth, stress response, and reproduction.
• Specific roles of prostaglandins and leukotrienes in pain, fever, and inflammation.

Hormone Regulation

• Negative Feedback: Hormone production decreases as a condition returns to normal.
• Positive Feedback: Hormone production increases in response to a condition (e.g., childbirth and oxytocin).

Major Endocrine Glands

• Glands with Hormone Production as Primary Function:
  • Pituitary, thyroid, parathyroid, adrenal, pineal glands.
• Glands with Additional Functions:
  • Hypothalamus, thymus, pancreas, ovaries, and testes.
• Other Hormone-Producing Organs:
  • Kidneys, stomach, liver, intestines, and heart.

Locations of Endocrine Glands

• Lower Body:
  • Testes (scrotum) and ovaries (pelvic cavity).
• Mid-Body:
  • Pancreas (behind stomach, near midline) and adrenal glands (on top of kidneys).
• Upper Body/Head:
  • Thymus (above heart), thyroid (neck), parathyroid (behind thyroid), hypothalamus, pituitary (base of the brain), and pineal (towards the back of the brain).

Summary

• The lecture covered the basics of the endocrine system, including terminology, functions, hormone types, regulation mechanisms, and gland locations. This sets the foundation for detailed study of endocrine gland interactions and hormone functions.