Endocrine System Overview

Introduction

• Focus on the AIT's version 7 human anatomy and physiology exam.
• Highlight on the endocrine system.
• Endocrine system consists of structures releasing hormones, can occur at cell level or organ level.

Key Endocrine Glands and Their Locations

• Brain: Hypothalamus, pineal gland, pituitary gland.
• Neck: Thyroid gland, parathyroid gland.
• Chest: Thymus gland.
• Above Kidneys: Adrenal glands.
• Near Stomach: Pancreas.
• Reproductive Glands: Ovaries (females), Testes (males).

Endocrine vs. Exocrine Glands

• Endocrine: Secrete hormones into bloodstream, no ducts needed.
  • Mnemonic: "Endo" in "endocrine" and "enter".
• Exocrine: Use ducts to transport secretions to body surfaces/cavities.
  • Mnemonic: "Ex" in "exocrine" and "exit".
• Example of mixed function: Pancreas (endocrine: insulin, glucagon; exocrine: digestive enzymes).

Hormone Roles and Composition

• Derived from amino acids or lipids (steroids).
• Hormone structure affects function and receptor binding.
• Triggers cells to perform specific actions (e.g., mitosis, enzyme activation).

Major Hormones and Functions

Brain Region

• Hypothalamus and Pituitary Gland:
  • Oversees endocrine system.
  • Pituitary Gland:
    • Posterior Pituitary: Stores/releases oxytocin (uterine contractions), ADH (water reabsorption).
    • Anterior Pituitary: Produces hormones e.g., growth hormone (growth), prolactin (milk production).
    • Mnemonics for hormones:
      • Oxytocin: "Obstetrics" (childbirth help).
      • ADH: "Can't pee" (water retention).
      • GH: "Grow High" (body growth).
      • PRL: "Produce Real Lactation".

Pineal Gland

• Secretes melatonin (regulates circadian rhythm).

Thyroid and Parathyroid Glands

• Thyroid Gland: T4, T3 (metabolic rate regulation), calcitonin (reduces blood calcium).
• Parathyroid Gland: Parathyroid hormone (increases blood calcium).
• Mnemonics:
  • T4/T3: "Thyroid".
  • Calcitonin: "Caletone it down".
  • Parathyroid Hormone: "Pushes calcium up".

Thymus Gland

• Produces thymosin (immune function, T cells production).
• Mnemonic: "Thy must stimulate immunity".

Adrenal Glands

• Adrenal Medulla: Epinephrine, norepinephrine (fight or flight response).
• Adrenal Cortex: Cortisol (stress, inflammation), aldosterone (electrolyte balance).
• Mnemonics:
  • Epinephrine/Norepinephrine: "Epi No Rush" (energy burst).
  • Cortisol: "Controls stress".
  • Aldosterone: "Aldo stores Na" (sodium retention).

Pancreas

• Insulin (helps cells absorb glucose), glucagon (raises blood glucose).
• Mnemonics:
  • Insulin: "Insulin puts sugar in" (lower blood sugar).
  • Glucagon: "Glucagon raises glucose".

Gonads (Ovaries and Testes)

• Ovaries: Estrogen (uterine lining, female characteristics), progesterone (maintains uterine lining, fetal development).
• Testes: Androgens/testosterone (sperm production, male characteristics).

Conclusion

• Understanding the endocrine system is crucial for exams like the AIT.
• Hormones regulate various bodily processes and are essential for maintaining homeostasis.
• Further resources available at nursechunkstore.com.