Pharm 111 Week 1 Study Guide

Respiratory System Study Guide - Introduction to the Lungs and Breathing Key Concepts

Respiratory System Components & Functions

• Main divisions: Conducting portion and Respiratory portion

• Primary components: Nose, Pharynx, Larynx, Trachea, Bronchi, Lungs, Bronchioles, Alveoli

• Functions: Air delivery, Filtering, Warming, Humidifying, Protection

Upper Respiratory System

• Respiratory mucosa lines conducting airways

• Features ciliated columnar epithelium and mucus-producing cells

• Vallecula: Important depression between tongue base and epiglottis

• Larynx contains important cartilages (thyroid, cricoid, epiglottis)

Lower Respiratory System

• Trachea branches into primary bronchi at carina

• Right primary bronchus: Larger, steeper angle (higher risk for aspiration)

• Bronchi branching pattern: Primary → Secondary (Lobar) → Tertiary (Segmental)

• Right lung: 3 lobes, 10 segments

• Left lung: 2 lobes, 8-10 segments

Alveoli & Gas Exchange

• Approximately 150 million alveoli per lung

• Surface area equivalent to half tennis court

• Key cells:

  • Type I pneumocytes (gas exchange)

  • Type II pneumocytes (surfactant production)

  • Alveolar macrophages (immune defense)

• Pores of Kohn allow inter-alveolar air movement

Breathing Mechanics

• Follows Boyle's Law: Pressure-volume relationship

• Primary muscles:

  • Diaphragm (75% of breathing effort)

  • External intercostals (25% of breathing effort)

• Inspiration: Active process

• Normal expiration: Passive process

Respiratory Control

• Medulla: Primary breathing control center

• Chemical control through:

  • Central chemoreceptors (CO₂ and H⁺ sensitive)

  • Peripheral chemoreceptors (O₂ sensitive)

• PaCO₂ is primary breathing regulator

Important Clinical Concepts

• Hypoxemia: Decreased blood O₂ (PaO₂ < 80 mmHg)

• Hypoxia: Decreased tissue O₂

Note: This study guide covers fundamental concepts of respiratory anatomy and physiology. Review additional class materials for complete understanding.