Human Anatomy and Physiology: Respiratory System

Introduction

• Focus on Chapter 22: Respiratory System.
• Learning Objectives:
  • Understand structures and functions of the respiratory system.
  • Grasp ventilation and perfusion nuances.
  • Comprehend gas exchange and blood gas transfer.

Functions of the Respiratory System

• Primarily provides oxygen for cellular respiration.
• Eliminates waste products like carbon dioxide.
• Maintains acid-base balance (pH regulation).
• Additional functions:
  • Senses odors.
  • Speech production.
  • Facilitates straining (e.g., coughing, childbirth).

Zones of the Respiratory System

• Conducting Zone:
  • Includes organs/structures not directly involved in gas exchange.
  • Brings air into the lungs.
• Respiratory Zone:
  • Involved directly in gas exchange.
  • Structures include respiratory bronchioles, alveolar ducts, alveoli.

Structures and Anatomy

• Alveoli:

  • Maximize surface area for gas exchange.

• Thoracic Cage:

  • Major bones: sternum, ribs, clavicle.
  • Muscles involved in breathing: external and internal intercostals, diaphragm.
  • Mechanics:
    • Ribs have elliptical shape aiding inspiration and expiration.
    • Expansion/contraction affects air intake/output.

• Lungs:

  • Pyramid-shaped, paired organs (left and right).
  • Connected to trachea by bronchi.
  • Enclosed by pleura (visceral and parietal layers).
  • Right lung: shorter, wider.
  • Left lung: smaller due to cardiac notch.
  • Blood supply by pulmonary arteries (deoxygenated blood) and veins (oxygenated blood).
  • Innervation by parasympathetic and sympathetic systems (bronchial dilation/constriction).

Pleura of the Lungs

• Visceral Pleura:
  • Superficial layer to lungs.
• Parietal Pleura:
  • Outer layer, connects to thoracic wall, mediastinum, diaphragm.
• Pleural Cavity:
  • Space between visceral and parietal pleura.
  • Contains pleural fluid for lubrication and preventing separation.

Respiratory Centers of the Brain

• Control centers in the brainstem regulate ventilation rhythm.
• Nerves coordinate inspiration (diaphragm, external intercostals) and expiration.

Development of the Respiratory System (Optional)

• Begins as early as weeks 4-8 in development.

These notes summarize the key points of the lecture on the respiratory system's structure and function. Use them to review the system's roles, anatomy, and physiological processes.