TEAS Review: Respiratory System

Overview

• The respiratory system supplies oxygen to the body and disposes of carbon dioxide.
• Involves structures like tubes and lungs.
• Interaction with the circulatory system is essential.

Respiration Processes

1. Pulmonary Ventilation: Breathing process.
2. External Respiration: Gas exchange at the lungs.
   • Lungs connected to the external environment.
3. Transport: Oxygen transported to body; carbon dioxide removed.
4. Internal Respiration: Gas exchange at tissues.
   • Oxygen delivered to cells; carbon dioxide picked up.

Respiratory System Structure

• Upper Respiratory System:

  • Nasal Cavity: Warms, moistens, and filters air.
  • Pharynx (Throat):
    • Subdivisions: Nasopharynx, Oropharynx, Laryngopharynx.
    • Shared by respiratory and digestive systems.
    • Contains uvula and epiglottis which prevent food from entering respiratory pathways.

• Lower Respiratory System:

  • Larynx: Voice box, responsible for speech.
  • Trachea: Contains cartilage rings preventing collapse; air pathway.
  • Bronchi and Bronchioles: Two bronchi divide into smaller bronchioles in the lungs.
  • Alveoli: Main site for gas exchange, look like grape clusters.

Lungs

• Right Lung: Three lobes, larger than left lung.
• Left Lung: Smaller, due to heart's position.
• Pleura: Double membrane structure around lungs containing pleural fluid to reduce friction.

Alveoli and Gas Exchange

• Alveoli surrounded by capillary beds for gas exchange.
• Gas Exchange Process:
  • Oxygen moves from alveoli (high concentration) to blood (low concentration).
  • Carbon dioxide moves from blood (high concentration) to alveoli (low concentration).
  • Surfactant prevents alveolar collapse during exhalation.

Factors Affecting Diffusion

• Concentration gradient is the primary factor.
• Surface Area: More area facilitates more diffusion.
• Distance: Shorter distances facilitate diffusion more efficiently.

Interaction with Circulatory System

• Oxygenated blood returns to left atrium and ventricle, then starts systemic circuit.
• Deoxygenated blood from systemic circuit enters alveoli for gas exchange.

Key Points

• Understanding structure and function of each respiratory part is essential.
• Interaction between respiratory and circulatory systems is crucial for oxygen delivery and carbon dioxide removal.
• Factors like surface area and diffusion distance impact the efficiency of gas exchange.