anatomy

Functions of the respiratory system

Includes providing surface area for gas exchange, moving air to/from lungs, protecting surfaces, producing sound, facilitating olfactory detection, and regulating blood pressure.

Upper respiratory system

Anatomical division of the respiratory system consisting of the nose, nasal cavity, paranasal sinuses, and pharynx.

Lower respiratory system

Anatomical division that includes the larynx, trachea, bronchi, bronchioles, and alveoli.

Respiratory tract

Passageways that carry air to and from the gas exchange surfaces of the lungs.

Conducting portion of the respiratory tract

Begins at the nasal cavity entrance and extends through the pharynx, larynx, trachea, bronchi, and larger bronchioles.

Respiratory portion of the tract

Includes the smallest bronchioles and alveoli where gas exchange occurs.

Alveoli

Air-filled pockets in the lungs where gas exchange between air and blood takes place.

Surface area for gas exchange

The surface area for gas exchange in lungs must be a very large portion, roughly 35 times the surface area of the body.

Respiratory mucosa

Lines the conducting portion of the respiratory system; consists of epithelium and lamina propria.

Mucosa

Often referred to as mucous membrane; contains epithelial and connective tissue layers.

Lamina propria

Underlying layer of areolar tissue that supports the respiratory epithelium.

Epithelium in the nasal cavity

Pseudostratified ciliated columnar epithelium with mucous cells.

Epithelium in the inferior pharynx

Stratified squamous epithelium, similar to the oral cavity.

Bronchioles structure

Bronchioles are surrounded by thick bands of smooth muscle that encircle or spiral around the lumen.