Lecture 1

• The functions of the respiratory system include gas exchange, where O2 passes from air to blood and CO2 passes from blood to air, as well as speech and smell.
• Air passes through the conducting portion of the respiratory system, which transports air and conditions it (warms, moistens, filters).
• The respiratory portion of the respiratory system is a thin, moist, delicate membrane where gaseous exchange occurs.
• The conducting portion of the respiratory system includes the oral cavity, nasal cavity, pharynx, larynx, and the thoracic cage.
• The thoracic cage consists of the ribs, costal margin, lungs, and heart.
• The thoracic cavity also contains the pulmonary cavities and mediastinum.
• The conducting portion of the respiratory system includes the trachea, bronchi, lungs, and the alveoli.
• There are differences between the right and left lungs.
• The pharynx is subdivided into the nasopharynx, oropharynx and laryngopharynx.
• The opening of the auditory tube in the nasopharynx serves a function.
• Respiratory muscles and accessory respiratory muscles have different functions.
• The larynx plays a role as a sphincter to protect the respiratory during swallowing.
• The tonsils, which include the pharyngeal, palatine and lingual tonsils, have clinical importance.
• The respiratory portion of the respiratory system consists of the alveolar sacs and the capillaries surrounding the alveolar sacs.
• The pulmonary vasculature includes the right pulmonary veins, arteries, and veins.
• The hilum is located on the medial aspect of the lung, next to the heart.
• The hilum of the left lung contains the pulmonary artery, pulmonary veins, and the primary bronchus dividing into secondary bronchi.
• The hilum of the right lung contains the pulmonary artery, pulmonary veins, and the primary bronchus dividing into secondary bronchi.
• Functional respiratory divisions include the conducting portion and the respiratory portion.
• Anatomical respiratory divisions include the upper respiratory tract (URT) which includes the nasal cavity, pharynx, larynx, and the lower respiratory tract (LRT) which includes the trachea, bronchi, lungs.
• The diaphragm separates the thorax from the abdomen, domes superiorly into the thoracic cage (higher on the right hand side), and contracts during inspiration and relaxes during expiration.
• The thoracic cage anatomy includes the thoracic inlet, thoracic outlet, thoracic inlet, and three planes of movement: vertical, antero-posterior, and transverse.
• The pleural cavity contains a thin film/fluid which aids the lungs in sliding and creates surface tension between the parietal and visceral layers to aid inspiration.
• The breathing mechanism involves fresh atmospheric air passing to alveoli and stale air leaving alveoli, and involves alternate increase and decrease in thoracic volume, via movements of the thoracic wall.
• The thoracic inlet is the area where the neck joins the thoracic cage.
• During breathing, the upper ribs increase antero-posterior diameter and the lower ribs increase transverse diameter.
• The functions of the thoracic cage include protection for vital organs and support for muscle attachment.
• The parietal pleura is located in the costodiaphragmatic recess.
• Changes in thoracic volume are essential for air to be drawn in to/forced out of the lungs.
• The fibres of the diaphragm converge towards a central tendon.
• The intercostal muscles are superior and inferior, and include vein, artery, and nerve components.
• The thoracic outlet is the area where the thoracic cage joins the abdominal cage.
• Each lung is surrounded by a membranous sac that encloses the pleural cavity.
• The pleura consists of the visceral pleura and parietal pleura, and the pleural cavity contains a thin film of serous fluid.
• The apertures in the posterior of the diaphragm allow for the passage of structures (vessels, nerves, oesophagus) between the thorax and abdomen.
• URT infections include common cold, the flu.
• LRT infections include bronchitis, pneumonia.
• The four nasal cavities are:

  1. Anterior = Nasal Cartilage
  2. Superior = Ethmoid Bone
  3. Inferior = Hard Palate and Soft Palate
  4. Posterior = Nasopharynx