Lecture on the Respiratory System

Introduction to Respiration

• Respiration: The process of breathing in oxygen and out carbon dioxide.
• Breathing: Happens automatically about 20,000 times a day.
• Lifespan Breaths: Approximately 600 million breaths by age 70.

Respiratory System Components

• Nose: Begins the process by filtering, warming, and moistening air.
  • Cilia: Tiny hairs that filter out dust and particles.
• Mouth: An alternative pathway for air intake.
• Pharynx (Throat): Connects nose and mouth paths; involved in digestion and respiration.
  • Esophagus: Pathway for food to the stomach.
  • Trachea (Windpipe): Pathway for air.
• Epiglottis: Flap that covers the air passage during swallowing to prevent food/liquid from entering the lungs.
• Larynx (Voice Box): Contains the vocal cords, located at the top of the trachea.
• Trachea: 2-3 cm tube extending 12 cm downwards from the larynx.
  • Reinforced by rings of cartilage to keep it open.
  • Lined with hairs to sweep out foreign particles.

The Pathway to the Lungs

• Bronchi: The trachea divides into two branches, each entering a lung.
  • Resemble tree limbs with finer branches called bronchioles.
• Bronchioles: End in tiny air sacs called alveoli.
• Alveoli: Structures that allow oxygen to enter blood and carbon dioxide to be expelled.
• Capillaries: Tiny blood vessels surrounding alveoli for gas exchange.

Impact of Exercise on the Respiratory System

• Increased Demand: Exercise increases the need for oxygen and the expulsion of carbon dioxide.
  • Body responds by increasing breathing rate and depth.
• Adaptation:
  • Over time, exercise enlarges the chest cavity.
  • Increases capillary formation around alveoli, improving gas exchange efficiency.

Conclusion

• The respiratory system is crucial for movement and is positively influenced by regular physical activity.