L15 - Respiratory system

• What systems are closely linked in the respiratory system?

  Respiratory and circulatory systems
• What is pulmonary ventilation?

  Movement of air into and out of lungs
• What occurs during external respiration?

  Exchange of O2 and CO2 between lungs and blood
• What is internal respiration?

  Exchange of O2 and CO2 between blood and tissues
• What are the major organs of the respiratory tract?

  • Nose
  • Paranasal sinuses
  • Pharynx
  • Larynx
  • Trachea
  • Bronchi and branches
  • Lungs and alveoli
• What is the function of the nose in the respiratory system?

  Warms, humidifies, and filters air
• What are the functions of the conducting and respiratory zones?

  • Conducting zone: Air transport pathways, no gas exchange
  • Respiratory zone: Site of gas exchange
• What is the role of the olfactory receptors in the nose?

  House olfactory receptors for smell
• What types of mucous membranes line the posterior nasal cavity?

  Olfactory mucosa and respiratory mucosa
• How do nasal conchae contribute to respiratory function?

  Increase mucosal surface area for air processing
• What are the three regions of the pharynx?

  Nasopharynx, oropharynx, laryngopharynx
• What is the function of the larynx?

  Provides an open airway and produces sound
• What type of cartilage is found in the larynx?

  Hyaline cartilage and elastic cartilage
• What is the role of the epiglottis?

  Closes off the larynx during swallowing
• How does the structure of vocal folds affect sound production?

  Length and tension determine pitch of sound
• What is the trachea commonly known as?

  Windpipe
• What type of epithelium lines the trachea?

  Ciliated pseudostratified columnar epithelium
• What is the function of C-shaped cartilaginous rings in the trachea?

  Support the trachea and prevent collapse
• How does the trachealis muscle affect airflow?

  Decreases diameter during contraction, increasing airflow
• What are the structural changes in the conducting zone as airways become smaller?

  1. Cartilage decreases until absent in bronchioles
  2. Epithelium changes from pseudostratified to simple cuboidal
  3. Increased smooth muscle alters airflow resistance
• What is the respiratory zone and its components?

  • Site of gas exchange
  • Begins with terminal bronchioles
  • Includes respiratory bronchioles, alveolar ducts, and alveolar sacs
• What are the types of alveolar cells?

  Type I and Type II alveolar cells
• What is the function of Type II alveolar cells?

  Secrete surfactant to reduce surface tension
• What is the role of alveolar macrophages?

  Phagocytose foreign particles in alveoli
• What forms the respiratory membrane?

  Capillary endothelium and alveolar epithelium
• What is the structure of the lungs?

  • Divided into lobes
  • Left lung: 2 lobes
  • Right lung: 3 lobes
  • Composed primarily of elastic connective tissue
• What are the functions of the pleurae?

  • Parietal pleura: Covers thoracic wall and diaphragm
  • Visceral pleura: Covers external lung surface
  • Pleural fluid: Lubricates space for friction-free movement
• What are the two circulations that serve the lungs?

  Pulmonary and bronchial circulation
• What is the role of the parasympathetic system in lung function?

  Causes bronchoconstriction
• What is the role of the sympathetic system in lung function?

  Causes bronchodilation
• What is the smooth muscle within the trachea called?

  Trachealis
• What are the true/false statements regarding the respiratory system?

  • Olfactory mucosa has goblet cells: False
  • Air encounters nasopharynx, then laryngopharynx, then oropharynx: False
  • Glottis is elastic cartilage: False
  • Pitch varies with vocal fold length and tension: True
  • Type II alveolar cells are phagocytic: False
  • Right lung is larger due to heart position: True
  • Bronchiole diameter controlled by both systems: True