The Endocrine System

Overview

• The endocrine system orchestrates bodily changes throughout our lives: growth, puberty, and reproduction.
• Regulates sleep, heart rhythm, and influences every cell in the body.
• Relies on glands, hormones, and cell receptors.

Components

Glands

• Hormone-producing glands:
  • 3 in the brain
  • 7 in the rest of the body
• Surrounded by blood vessels to extract ingredients for hormone production.

Hormones

• Manufactured by glands and released into the bloodstream in small amounts.
• Target specific cells to induce changes.

Receptors

• Special proteins on/in cells that recognize and bind to specific hormones.
• Hormone-receptor binding triggers effects that alter cell processes.

Functions of Hormones

• Thyroid hormones (triiodothyronine and thyroxine):

  • Influence energy use and cell activity
  • Regulate breathing, heartbeat, body temperature, and digestion.

• Puberty Hormones:

  • Testosterone: In men, leads to sexual organ development, facial hair growth, voice deepening, and height increase.
  • Estrogen: In women, leads to body development, hip widening, thickening of the womb lining (prepares for menstruation or pregnancy).

Misconceptions

• Both men and women have estrogen and testosterone in different amounts.
• Hormones influence but do not control behavior.

Mood and Hormonal Changes

• Hormones influence brain chemicals like serotonin, affecting mood.

Hormonal Disorders

• Diabetes: Pancreas secretes too little insulin, affecting blood sugar management.
• Hypothyroidism: Too little thyroid hormone; causes slow heart rate, fatigue, and depression.
• Hyperthyroidism: Too much thyroid hormone; causes weight loss, sleeplessness, and irritability.

Conclusion

• The endocrine system maintains body balance and drives essential changes for growth and development.