Lecture Notes: The Respiratory System

Overview

• Chapter Focus: Respiratory System (Chapter 22)
• Sections 1-3: Anatomy heavy, more relevant for lab
  • Basic overview provided for lecture exam purposes
  • In-depth study required for lab

Connection with Circulatory System

• Both systems are involved in gas exchange

Major Functions of the Respiratory System

• Gas Exchange: Oxygen pickup and carbon dioxide removal
• Olfaction: Sense of smell
• Speech: Movement of air aids in speech

Processes Involved in Respiration

• Respiratory System:
  • Pulmonary Ventilation: Breathing (air movement in and out of lungs)
  • External Respiration: Gas exchange between lungs and blood
• Circulatory System:
  • Transport: Blood transports gases throughout the body
  • Internal Respiration: Gas exchange between blood vessels and tissues

Major Organs

Upper Respiratory System

• Components: Nose, nasal cavity, paranasal sinuses, pharynx
• Function: Warm, humidify, and filter incoming air
• Pharynx Subdivisions:
  • Nasopharynx: Behind nasal cavity
  • Oropharynx: Behind tongue
  • Laryngopharynx: Connects to larynx

Lower Respiratory System

• Components: Larynx, trachea, bronchi, lungs, alveoli
• Zones:
  • Respiratory Zone: Site of gas exchange (respiratory bronchioles, alveolar ducts, alveoli)
  • Conducting Zone: Transport gas, cleanse, warm, and humidify air

Specific Structures and Functions

• Larynx: Houses vocal cords
  • True Vocal Cords: Responsible for voice production
• Trachea: Also known as 'windpipe'
• Epiglottis: Guardian of airways

Voice Production

• Speech: Intermittent release of expired air as glottis opens/closes
• Pitch: Determined by length/tension of vocal cords
• Loudness: Depends on air force

Respiratory Membrane

• Composition: Alveolar wall, basement membrane, capillary wall
• Function: Gas exchange via simple diffusion
• Cell Types:
  • Type 1 Alveolar Cells: Simple squamous epithelial
  • Type 2 Alveolar Cells: Secrete surfactant and antimicrobial proteins
  • Macrophages: Digest bacteria, dust, debris

Lung Structure

• Lungs: Left and right differ in size/shape
  • Left Lung: Smaller, 2 lobes (superior and inferior)
  • Right Lung: Larger, 3 lobes (superior, middle, and inferior)

Circulation

• Pulmonary Circulation:
  • Arteries: Carry low-oxygen blood to lungs
  • Veins: Carry oxygen-rich blood to heart
• Bronchial Circulation: Provides oxygenated blood to lung tissue

Nervous System Innervation

• Parasympathetic Fibers: Cause bronchoconstriction
• Sympathetic Fibers: Cause bronchodilation

Pleurae

• Visceral Pleura: Covers lung surface
• Parietal Pleura: Lines thoracic cavity
• Pleural Fluid: Provides lubrication and tension reduction

Summary

• Understand major functions, processes, and structures of the respiratory system.
• Recognize the interconnection between respiratory and circulatory systems for comprehensive understanding of gas exchange.