Respiratory System - ATITs Version 7

Introduction

• Focus on the respiratory system for AT&T's version 7 human anatomy and physiology exam.

Respiratory System Structure

• Nasal Cavity: Warms, humidifies, and filters air with mucus and nasal hairs.
• Pharynx: Crossroads for food (esophagus) and air (larynx).
• Larynx (Voice Box): Air pathway.
• Trachea: Supported by cartilage rings, prevents food entry via the epiglottis.
• Bronchi and Lungs:
  • Trachea splits into primary bronchi for each lung.
  • Right lung: 3 lobes; Left lung: 2 lobes (with cardiac notch).
  • Bronchi split into secondary, tertiary bronchi, bronchioles, and alveolar ducts.
  • Alveoli: Site of gas exchange.

Zones of the Lungs

• Conducting Zone: Trachea, bronchi, terminal bronchioles; warms, humidifies, and filters air.
• Respiratory Zone: Respiratory bronchioles, alveolar ducts, alveoli; site of gas exchange.

Gas Exchange

• Function: Oxygen enters blood, CO2 removed.
• Alveoli: High surface area and blood supply for effective exchange.

Interaction with Other Systems

• Circulatory System: Red blood cells transport O2 and CO2.
• Skeletal System: Ribs protect lungs.
• Muscular System:
  • Intercostal Muscles: Assist with thoracic expansion.
  • Diaphragm: Controls vertical expansion of the thoracic cavity.

Breathing Mechanism

• Inspiration (Inhalation):
  • Active process; diaphragm contracts, intercostal muscles pull rib cage up/out.
  • Increases thoracic volume, creating negative pressure for air inflow.
• Expiration (Exhalation):
  • Passive process; diaphragm relaxes, rib cage moves down/in.
  • Decreases thoracic volume, pressure increase pushes air out.
  • Forced Expiration: Active during exercise/coughing.

Perfusion and Ventilation

• Ventilation: Air movement in/out of lungs.
• Perfusion: Blood flow to alveolar capillaries for gas exchange.
• Balance Between Ventilation and Perfusion:
  • Ideal: Matched ventilation and perfusion.
  • Imbalance: Can lead to hypoventilation or hyperventilation.

Respiratory Conditions

• Hypoventilation:
  • Inadequate ventilation; high CO2 (hypercapnia), low O2 (hypoxia).
• Hyperventilation:
  • Excessive ventilation; low CO2 (hypocapnia), high O2 (hyperoxia).
  • Can lead to respiratory alkalosis (increased blood pH).

Conclusion

• Encouragement to use additional resources for exam preparation.
• Invitation to ask questions for further clarification.