2.1 Function of the Respiratory System

Comprehensive vocabulary flashcards covering anatomical structures, functions, and respiratory mechanics from Section 2.1 Function of the Respiratory System.

Epiglottis

A structure composed of cartilage that normally points upward but tilts back during swallowing to cover the trachea (windpipe), directing food down the esophagus into the stomach.

Larynx

A hollow cartilage tube in the neck known as the 'voice box' that funnels air from the mouth and nose down the trachea, houses the vocal cords, and is visible externally in men as the Adam's apple.

Vocal Chords

Structures located inside the larynx composed of ligaments and muscles that function to produce noise and sound.

Trachea

The main airway tube, known as the 'windpipe', that connects outside air to the lungs and is lined with epithelial tissue producing mucus to trap dust, pollen, pollution, and pathogens.

C-shaped Cartilage Rings

Incomplete rings of cartilage supporting the trachea, with the open portion of the 'C' facing posterior next to where the esophagus (food pipe) runs.

Cilia

Small hair-like structures lining the respiratory tract that waft trapped mucus and foreign particles upward toward the throat to be swallowed.

Bronchi

Two large airways (singular: bronchus) formed by the bifurcation of the trachea that lead into each lung and divide into smaller pathways; unlike the trachea, they feature complete, full rings of cartilage.

Bronchioles

Very narrow airway branches connecting the bronchi to the alveoli; they lack cartilage rings, contain cilia, and feature cells that produce enzymes to break down particles reaching the lungs.

Alveoli

Clusters of approximately 300 million tiny air sacs surrounded by extensive capillary networks where gas exchange occurs, allowing inhaled oxygen to enter the blood and carbon dioxide to exit.

Diaphragm

A major respiratory muscle sheet spanning the base of the chest cavity (thorax); it assumes a dome shape when relaxed and flattens upon contraction during inhalation to expand the thoracic cavity.

Ribs

A set of 12 pairs of protective bones attached to the spine at the back and joined to the sternum at the front by flexible cartilage, encasing and shielding the heart and lungs.

Internal Intercostal Muscles

A thin layer of muscle tissue positioned toward the inside of the rib cage that contracts during active, forced exhalation (such as coughing or heavy breathing) to pull the ribs inward and downward.

External Intercostal Muscles

Muscles oriented at right angles to the internal intercostals on the outer rib cage that contract during inhalation to pull the ribs upward and outward, expanding thoracic volume.

Pleural Membrane

A continuous double-layered membrane that covers the exterior surface of the lungs and folds back to line the inner chest wall, ensuring the lungs expand in tandem with the thorax during breathing.

Pleural Cavity

The potential fluid-filled space located between the two layers of the pleural membrane.

Pleural Fluid

The lubricating fluid contained between the two pleural layers that enables them to slide friction-free past one another during respiration while resisting pulling forces that would separate them.