Respiratory System Review

• The respiratory system consists of passages that filter incoming air and transport it to the lungs.
• By the end of this lecture, you should be able to identify the general functions/locations/ and functions of the respiratory system.
• Be able to list the Anatomical divisions of the pharynx (openings into and between its divisions), cartilages and muscles of the larynx.

Respiration Events

• Ventilation: movement of air in and out of the lungs
• External Respiration: Gas exchange between blood and lungs
• Transport of gases from the lungs to the body cells via blood
• Internal Respiration: Gas exchange between the blood and body cells
• Cellular Respiration: oxygen use and production of carbon dioxide by body cells

Organs of the Respiratory System

• Upper respiratory system: Nose, Nasal cavity, Sinuses, and Pharynx
• Lower respiratory system: Larynx, Trachea, Bronchial tree, and the Lungs

Nose: (Surface Anatomy)

• Covered with skin
• Supported internally by cartilage and bone
• Contains two nostrils

Nasal Cavity

• Space behind the nose
• Medially contains the Nasal Septum
• Laterally contains Conchae and Meatuses
• Superiorly contains the Cribriform plate (of ethmoid bone)
• Inferiroly contains the Hard plate

Mucous Membrane

• Composed of ciliated epithelium
• Cilia filters the air
• Goblet cells produce mucus to moisten the air and trap any particles
• Rich with blood vessels, which warms incoming air

Paranasal Sinuses

• Air filled spaces which open into the nasal cavity
• The following reduce the weight of the skull: Frontal sinus, Ethmoid sinus, Sphenoid sinus, and Maxillary sinus
• Acts as a resonant chamber to affect the quality of the voice

Pharynx

• Passage way for air and food, that leads to the nasal and oral cavity
• Nasopharynx, Oropharynx, and Laryngopharynx are divisions of the pharynx

Larynx

• Superior to the trachea
• Enlargement in the airway superior to the trachea
• It prevents particles entering the trachea
• Houses vocal, and composed of a framework of muscles and cartilage bound by elastic tissue

Larynx Folds

• Inside the larynx, there are two horizontal folds
• Upper false vocal folds: Do not produce sound and close the airway during swallowing
• Lower true vocal folds: Vibrate to produce sound
• Contraction controls the pitch
• Force of air through the cords controls the intensity/loudness

Trachea

• Flexible cylindrical tube that is anterior to the Oesophagus
• Splits into the right and the left bronchi
• Lined with ciliated mucous membrane with goblet cells
• Twenty C-shaped pieces of hyaline cartilage

Tracheostomy

• A blocked trachea results in asphyxiation
• Tracheostomy is a life-saving procedure where an external opening is made in the trachea

Bronchial Tree

• Consists of these branched tubes leading from the trachea to the alveoli: Main (primary) bronchi, Lobar (secondary) bronchi, Segmental (tertiary) bronchi Intralobular bronchioles, and Terminal bronchiole
• Alveolar ducts, Alveolar sacs and Alveoli

Right vs Left Main Bronchi

• The right main bronchus is a short, wide air passageway to the right lung
• The left is a narrow/long passageway into the left lung

Lungs

• Are located in the thorax (cone-shaped/spongy) and separated by the mediastinum
• Vessels and bronchi enter the hilum and are covered by the visceral and the parietal pleura.
• The space between the two layers is the plural cavity
• The right lung is larger than the left
• Fissures divide the lungs into lobes.
• Each lobe is supplied by the bronchial tree, blood vessels, nerves & lymph vessels

Lobar Pneumonia

• Classically been described as a process which spreads contiguously throughout part of, or an entire lobe of the lung.

Test your knowledge of the respiratory system. Topics cover the sequence of respiration, protective mechanisms, and potential issues like choking. Questions also address gas exchange and the role of the larynx.