Anatomy Practical
[PHL 212]
Respiratory System
Function of the Respiratory System
 Trap irritants / infectious
particles
 Moistens
and
warms
incoming air
 Breathing process
 Oversees gas exchanges
Exchange O2
 Air to blood & Blood to cells
Exchange CO2
 Cells to blood & Blood to air
 Exchange of gasses takes
place within the lungs in
the alveoli
 Enable speech production
Organs of the Respiratory system
 Nose
 Pharynx
 Larynx
 Trachea
 Bronchi
 Lungs –
alveoli
Upper Respiratory Tract
Anatomy of the Nasal Cavity
 Nose is primary passageway for air entering respiratory
system
 Nasal septum : divides cavity into right & left halves
 The cavity is lined with respiratory mucosa
 Moistens air
 Traps incoming foreign particles
 Lateral walls have projections called conchae
 Increases surface area
 The nasal cavity is separated from the oral cavity by the
palate
 Anterior hard palate (bone)
 Posterior soft palate (muscle)
Paranasal Sinuses
 Cavities within bones surrounding the nasal cavity
 Frontal bone
 Sphenoid bone
 Ethmoid bone
 Maxillary bone
 Function of the sinuses
 Lighten the skull
 Produce mucus that drains into the nasal cavity
Pharynx (Throat)
 Pharynx is shared by digestive & respiratory systems
 Muscular passage from nasal cavity to larynx
 Three regions of the pharynx
 Nasopharynx – superior region behind nasal cavity
 Oropharynx – middle region behind mouth
 Laryngopharynx – inferior region attached to larynx
 The oropharynx and laryngopharynx are common
passageways for air and food
 Tonsils of the pharynx
 Pharyngeal tonsil (adenoids) in the nasopharynx
 Palatine tonsils in the oropharynx anterior to ear
 Lingual tonsils at the base of the tongue
Larynx (Voice Box)
 Inspired air leaves pharynx by passing through
a narrow opening – glottis
 Larynx surrounds & protects glottis
 Routes air and food into proper channels
 Plays a role in speech
CARTILAGES OF LARYNX
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Thyroid cartilage
Epiglottis
Cricoid Cartlage
Cuneiform cartilages
Corniculate cartilages
Arytenoid cartilages
PAIRED
Trachea (Windpipe)
 Trachea is a tough, flexible tube with
diameter of 2.5cm & length of 11cm
 Connects larynx with bronchi
 Branches to form right & left primary
bronchi
 Lined with ciliated mucosa
 Beat continuously in the opposite direction
of incoming air
 Expel mucus loaded with dust and other
debris away from lungs
Bronchi
 Primary bronchi formed by division of the trachea
 Enters the lung at the hilus (medial depression)
 Right bronchus is wider, shorter, and straighter
than left
 Bronchi subdivide into smaller and smaller
branches
Lungs
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Occupy most of the thoracic cavity
Apex is near the clavicle (superior portion)
Base rests on the diaphragm (inferior portion)
Each lung is divided into lobes by fissures
Coverings of the Lungs
 Pulmonary (visceral) pleura covers the lung
surface
 Parietal pleura lines the walls of the thoracic
cavity
 Pleural fluid fills the area between layers of
pleura to allow gliding
Lungs
Respiratory Tree Divisions
 Primary bronchus
 Secondary bronchus
 Tertiary bronchus
 Bronchiole
 Terminal bronchiole
Bronchioles & Alveoli
 Smallest branches of the bronchi
 Terminal bronchioles end in alveoli
 Structure of alveoli
 Alveolar duct
 Alveolar sac
 Alveolus