Endocrine System

Endocrine System: Structure and Function

Introduction

The endocrine system is a network of glands that produce hormones, which regulate various bodily functions such as metabolism, growth, reproduction, and mood. It works alongside the nervous system to maintain homeostasis.

Major Endocrine Glands and Their Functions

1. Hypothalamus

• Located in the brain, it links the endocrine and nervous systems.
• Controls hormone release from the pituitary gland.

2. Pituitary Gland (Master Gland)

• Divided into the anterior and posterior lobes.
• Regulates growth, metabolism, and reproductive hormones.
• Key hormones: Growth hormone (GH), Adrenocorticotropic hormone (ACTH), Thyroid-stimulating hormone (TSH), Prolactin, Oxytocin, Antidiuretic hormone (ADH).

3. Thyroid Gland

• Located in the neck, regulates metabolism.
• Produces Thyroxine (T4) and Triiodothyronine (T3).
• Releases Calcitonin, which lowers blood calcium levels.

4. Parathyroid Glands

• Small glands behind the thyroid.
• Secrete Parathyroid Hormone (PTH) to regulate calcium levels.

5. Adrenal Glands

• Located above the kidneys, involved in stress response.
• Adrenal Cortex produces Cortisol (stress response) and Aldosterone (fluid balance).
• Adrenal Medulla releases Epinephrine (adrenaline) and Norepinephrine.

6. Pancreas

• Functions as both an endocrine and exocrine gland.
• Regulates blood sugar through Insulin (lowers glucose) and Glucagon (raises glucose).

7. Gonads (Ovaries and Testes)

• Ovaries (female) produce Estrogen and Progesterone for reproductive health.
• Testes (male) produce Testosterone for male characteristics and sperm production.

8. Pineal Gland

• Located in the brain, controls sleep-wake cycles.
• Produces Melatonin, which regulates circadian rhythm.

Functions of the Endocrine System

• Regulates metabolism and energy balance.
• Controls growth and development.
• Maintains electrolyte and water balance.
• Manages stress response and immune functions.
• Regulates reproductive processes.

Common Endocrine Disorders

• Diabetes Mellitus: Insufficient insulin production or usage.
• Hypothyroidism/Hyperthyroidism: Imbalance in thyroid hormone production.
• Cushing’s Syndrome: Excess cortisol levels.
• Addison’s Disease: Deficiency of adrenal hormones.

Maintaining a balanced diet, regular exercise, and stress management are crucial for endocrine health.