Conducting Zones

Conducting Zones (Dead Space)

Respiratory passages extending from the nose to the terminal bronchioles.

Respiratory Zones

Actual sites of gas exchange, composed of respiratory bronchioles, alveolar ducts, and alveoli.

Nose

Divided into the external nose and internal nasal cavity.

External Nose Boundaries

Superiorly - nasal and frontal bones, Laterally - maxillary bones, Inferiorly - plates of hyaline cartilage.

Nasal Cavity

Lies posterior to the external nose, air enters through external nares or nostrils.

Nasal Septum

Divides the nasal cavity at the midline.

Nasal Cavity Roof

Ethmoid bone, sphenoid bone, frontal bone.

Nasal Cavity Floor

Hard palate.

Nasal Cavity Lateral Structures

Conchae (superior, middle, inferior) with grooves called meatus.

Nasal Cavity Medial Structure

Nasal septum formed anteriorly by hyaline cartilage, posteriorly by vomer bone and perpendicular plate of ethmoid.

Pharynx

Common pathway for food and air, extends from skull base to C6.

Nasopharynx

Serves only as an air passageway.

Pharyngeal Tonsil (Adenoid)

Located high on the posterior wall of the nasopharynx.

Oropharynx

Extends from the soft palate to the epiglottis, passage for swallowed food and inhaled air.

Laryngopharynx

Common passageway for food and air.

Larynx

Voice box, extends from C4 to C6.

Larynx Attachments

Superiorly to the hyoid bone and laryngopharynx, inferiorly continuous with the trachea.

Larynx Cartilage Framework

Nine cartilages connected by membranes and ligaments.

Thyroid Cartilage

Shield-shaped, forms the Adam’s apple.

Cricoid Cartilage

Signet ring-shaped cartilage below the thyroid cartilage.

Epiglottis

Spoon-shaped elastic cartilage, prevents food from entering the larynx.

Epiglottis Function

Covers the laryngeal inlet during swallowing, known as the "guardian of the airways."

Arytenoid Cartilage

Anchors the vocal cords to the larynx.

Cuneiform Cartilage

Found in the aryepiglottic fold.

Corniculate Cartilage

Found at the apices of the arytenoid cartilage.

Vocal Cords

Supported by vocal ligaments, vibrate to produce sound.

True Vocal Cords

Produce sound as air rushes from the lungs.

False Vocal Cords (Vestibular Folds)

Located superior to true vocal cords, do not produce sound.

Trachea

Windpipe, 10-12 cm long, 2.5 cm in diameter.

Trachea Reinforcement

Contains 16-20 C-shaped rings of hyaline cartilage.

Bronchi

Right and left bronchi form by the division of the trachea at the sternal angle.

Bronchioles

the air passages under 1 mm in diameter, and the tiniest of these are the terminal bronchioles with 0.5 cm in diameter