Functions of the Respiratory System

Study Notes

Nose: Responsible for warming and moistening incoming air.
Palantine Bone: Separates the nasal cavity from the mouth; improper formation leads to cleft palate, causing swallowing and speaking difficulties.
Septum: Divides the nasal cavity into right and left nostrils; has a rich blood supply.
Sinuses: Four air-filled spaces that drain into the nose, helping to reduce skull weight.
Pharynx (Throat): Extends from the base of the skull to the esophagus, divided into three sections:
- Nasopharynx: Located behind the nose, extends to the soft palate.
- Oropharynx: Behind the mouth, from soft palate to hyoid bone; contains tonsils.
- Laryngopharynx: From hyoid bone to the esophagus; changes shape for vowel production.
Larynx (Voice Box): Connects the root of the tongue to the upper end of the trachea and is made up of cartilage; contains two sets of folds:
- Vestibular Folds: Also known as false vocal cords.
- True Vocal Cords: Involved in sound production.
Thyroid Cartilage: Known as the Adam's apple, larger in males due to testosterone levels.
Epiglottis: A flap that covers the trachea during swallowing, preventing food from entering the airway.

Trachea: The windpipe running from the larynx to the bronchi, composed of C-shaped cartilage rings; a tracheostomy can create an opening for breathing.
Bronchi: Tubes branching from the trachea into the lungs and ciliated in structure, which include:
- Primary Bronchi
- Secondary Bronchi
- Tertiary Bronchi
- Bronchioles: Smaller branches that lead to alveolar ducts and terminate in alveolar sacs, where gas exchange occurs.

Lungs extend from the diaphragm to the clavicles, divided into lobes by fissures.
Covered by two layers of pleura:
- Visceral Pleura: Adheres directly to the lung surface.
- Parietal Pleura: Lines the inner surface of the ribs.
Pleural fluid exists between the visceral and parietal pleura, aiding in lung function.