Pulmonary System

• Pulmonary System


  • Ventilation and perfusion
  • Respiration
  • Transport of oxygen and CO2
  • Diffusion of oxygen and CO2
• Ventilation


  1. Inhalation and exhalation

  2. Acting of moving air in and out of the lungs
• Boyle's law


  • Inhale air goes inside lungs
  • Exhale air goes outside lungs
• Perfusion


  Pulmonary blood flow
• Normal ventilation perfusion


  V/Q ratio or FEV1/FVC ratio: 0.8 or 80%
• Blood is gravity dependent
• FEV1


  Force expiratory volume in 1 second
• FVC


  Force vital capacity (perfusion/blood flow)
• Alveolar ventilation/pulmonary blood flow is 4L/min÷ 5L/min
• COPD


  Chronic obstructive pulmonary disease, FEV1/FVC ratio <0.8
• CRPD


  Chronic restricted pulmonary disease, FEV1/FVC ratio >0.8
• Types of respiration


  • External respiration between alveoli and capillaries
  • Internal respiration between capillaries and tissues
• Arteries


  Small capillaries
• Veins


  Small veins
• Cell


  Basic component of tissue
• Cell > tissue > organ > system > organism
• CVA


  Cerebral vascular accident (stroke)
• Diffusion


  From higher to lower concentration (passive process)
• Passive process doesn't require energy
• Upper respiratory tract


  • Nose
  • Pharynx
  • Larynx
• Nose


  Considered as large mucosal surface area, filters and warms/humidifies air
• Vibrissae


  Filters the oxygen that goes inside
• Pharynx


  Common area for respiration (air) and gastrointestinal (food), 3 divisions: nasopharynx, oropharynx, laryngopharynx
• Larynx


  Sound production, ensures that air will pass through trachea
• Epiglottis


  Leaflet cartilage, functions as a sphincter, "the guardian of the airways"
• Lower respiratory tract (tracheobronchial tree)


  • Conducting zone (passage way of air - no gas exchange yet)
  • Respiratory zone/acinus/acini - functional unit of lungs (responsible for gas exchange)
• Conducting zone


  • Trachea
  • Main bronchi
  • Lobar bronchi
  • Segmental bronchi
  • Terminal bronchioles
• Respiratory zone


  • Respiratory bronchioles
  • Alveolar ducts
  • Alveolar sacs
  • Alveoli
  • Capillaries
• Anatomy of right lung

  • Horizontal fissure
  • Oblique fissure
  • Superior/upper lobe
  • Middle lobe
  • Inferior/lower lobe
• Anatomy of left lung


  • Oblique fissure
  • Superior/upper lobe
  • Inferior/lower lobe
  • Cardiac notch
  • Lingula
• Types of pleura

  • Visceral pleura - membrane that covers lungs and its fissures
  • Parietal pleura - membrane that covers the thoracic wall
• Pleural cavity/space


  Normal pressure inside is (-) 4mmHg
• Pneumothorax


  • Pleural effusion - excessive accumulative of fluid
  • Atelectasis - collapse of lung due to tiny air sacs within the lung, called alveoli, lose air.
• Pleural fluid


  Lubricates the pleura, shock-absorption
• Respiratory distress syndrome/hyaline membrane disease


  Condition in newborn where surfactant is inadequate, leading to collapse of small alveoli
• Boundaries of thorax/thoracic cage/rib cage


  • Anterior: sternum
  • Posterior: thoracic vertebrae (T1-12)
  • Lateral: Ribs (12 pairs)
• Types of ribs


  • True (1-7) - attached to sternum via costal cartilage
  • False (8-10) - no attachment with sternum, attached to 7th rib via costal cartilage
  • Floating (11-12) - no attachment with sternum and other ribs
• Superior boundary of thorax


  Thoracic outlet
• Muscles of respiration


  • Relaxed inspiration: diaphragm, external intercostals
  • Forced inspiration (accessory muscles): sternocleidomastoid, upper trapezius, pectoralis major and minor, anterior/middle/posterior scalene, serratus anterior and posterior superior
  • Relaxed expiration: no muscles involved, elastic/passive recoil of lungs and thorax
  • Forced expiration: abdominals, serratus posterior inferior, internal intercostals
• Controls of respiration


  • Dorsal respiratory group (DRG) - inspiration
  • Ventral respiratory group (VRG) - expiration and inspiration
  • Pneumotaxic center - limits inspiration
  • Apneustic center - prevents switching off of inspiration
  • Chemoreceptors - central and peripheral