🫁 Respiratory System Study Guide

Gas exchange

Occurs in the alveoli; takes in O₂ and expels CO₂.

Alveoli

Tiny air sacs where gas exchange occurs.

Larynx

Voice box that prevents food from entering the trachea.

Epiglottis

Flap that blocks food from entering the larynx.

Trachea

Windpipe lined with ciliated epithelium and supported by C-shaped cartilage.

Type I alveolar cells

Thin cells that form the respiratory membrane for gas exchange.

Surfactant

Substance produced by Type II alveolar cells that reduces surface tension.

Respiratory volumes

Measurements of air volumes in the lungs during different phases of breathing.

Inspiration

The process of breathing in, primarily involving the diaphragm.

Functional Residual Capacity (FRC)

The amount of air remaining in the lungs after normal exhalation.

Right main bronchus

Wider and shorter bronchus, more prone to aspiration.

Pleural cavity

Space between the visceral and parietal pleura, containing pleural fluid.

Diaphragm

Main muscle responsible for inspiration.

Residual Volume (RV)

Air left in the lungs after a forceful exhalation.

Tidal Volume (TV)

The amount of air inhaled or exhaled during normal quiet breathing.

Left lung cardiac notch

Indentation in the left lung to accommodate the heart.

Hilum

Region where bronchi, blood vessels, and nerves enter/leave the lung.

Internal intercostals

Muscles involved in forced exhalation.

External intercostals

Muscles that assist with active inspiration.