Pablo_Pareja.Thymus and Pineal Gland (1)

Introduction to Endocrine System

• Endocrine Glands: Secrete hormones that act on target cells.

• Homeostasis: Eight glands maintain chemical balance through:

  • Hormone Production

  • Negative Feedback Mechanisms

  • Hormones are produced in response to chemical shifts in the body.

Thymus Gland

• Location: Anterior mediastinum. Greek origin "Thymos" means soul/spirit.

• Function: Small organ producing T lymphocytes for immune response.

• Hormones:

  • Thymosin: Crucial for T cell production.

  • Thymopoietin: Involved in T cell regulation and maturation.

• Importance: Critical for early life; regresses with age.

T Lymphocytes

• Role in the adaptive immune response.

• Essential for fighting germs and disease.

Pineal Gland

• Shape and Location: Resembles a pine cone; located at the roof of the third ventricle.

• Hormone: Secretes melatonin, influencing sleep patterns and circadian rhythms.

• Function: Active during childhood; reacts to light through optic nerve.

Circadian Rhythms

• Definition: Predictable physiological cycles based on a 24-hour day.

• Melatonin Secretion: High in childhood, decreases at puberty; aids in deeper sleep.

• Commercial Use: Over-the-counter melatonin marketed as a sleep aid.

References

• Ilahi, S., Beriwal, N., & Ilahi, T. B. (2023). Physiology, Pineal Gland. StatPearls.

• Kathleen Anne Ireland. (2018). Visualizing Human Biology, Fifth Edition.

• Kooshesh, K. A. et al. (2023). Health Consequences of Thymus Removal. New England Journal of Medicine.

• Professional, C. C. M. (2024). T Cells. Cleveland Clinic.

• Remien, K., & Jan, A. (2023). Anatomy, Head and Neck, Thymus. StatPearls.