Human Respiratory System Anatomy and Function Explained

Respiratory System Function

The respiratory system is responsible for gas exchange, where CO₂ is removed from venous blood and atmospheric O₂ is absorbed into the bloodstream.

Respiratory Organs

• Conducting Tubes: These structures clean, heat, and transport atmospheric air into the lungs. This includes the trachea, pharynx, and larynx.
• Lungs: Essential organs where gas exchange occurs.

Nasal Anatomy

• Nostrils: Two cavities in the center of the face serving as the gateway to the respiratory system.
• Nose: An osteochondral prominence located in front of the nostrils.
• Choanae: Posterior nasal orifices.

Nasal Cavity Walls

• Roof: Formed by bone.
• Floor: Composed of the hard palate and soft tissue.
• Septum: Features anterior cartilage and posterior bone.
• Outer Wall: Formed by several bones, including three turbinate structures (superior, middle, and inferior). The spaces between these are called meatuses. The inferior meatus contains the nasolacrimal duct.

Nasal Cavity Regions

• Vestibule: The area adjacent to the external nostrils, covered in skin and hair to filter foreign particles.
• Respiratory Region: Occupies the lower and middle turbinates. Lined with red mucosa (pituitary), it is highly vascular to heat and humidify inspired air.
• Olfactory Region: Corresponds to the superior turbinate. Coated with yellow pituitary cells, it is sensitive to gaseous particles for the sense of smell.

The Larynx

Located in the anterior neck, the larynx connects the pharynx to the trachea. Its primary functions are air passage, phonation, and swallowing.

Larynx Wall Structure

• Cartilages: The skeleton of the larynx. Key structures include the cricoid, thyroid (Adam's apple), and epiglottis. The epiglottis acts as a lid, preventing food from entering the larynx during swallowing.
• Muscles: Intrinsic muscles that mobilize the larynx.
• Mucosa: The internal lining of the organ.