Respiratory System Overview

Functions of the Respiratory System

• Provides oxygen to the body.

• Removes carbon dioxide.

• Maintains acid-base (pH) balance in the body.

Respiratory Anatomy

Structures

• Upper Respiratory Tract: Includes nasal cavity, pharynx, and larynx.

• Lower Respiratory Tract: Consists of trachea, bronchi, and lungs.

Lung Functionality

Elasticity and Recoil

• Lungs contain elastic tissue that helps them expand and contract during breathing.

Surfactant Role

• Surfactant reduces surface tension within alveoli, preventing collapse and aiding re-expansion.

Intrapleural Pressure

• Maintains lung expansion and prevents collapse.

• When the pressure is disrupted, it can lead to pneumothorax (collapsed lung).

Gas Exchange in the Lungs

Mechanism

• Oxygen enters the blood from alveoli, and carbon dioxide exits the blood into alveoli (diffusion).

Chemical Control of Breathing

Regulation

• Controlled primarily by chemoreceptors that monitor CO2 levels.

• Increases or decreases in CO2 stimulate changes in respiratory rates to maintain homeostasis.

Transportation of Gases

• Oxygen: 98% bound to hemoglobin, 2% dissolved in plasma.

• Carbon Dioxide: 20% bound to hemoglobin, 10% dissolved, 70% converted to bicarbonate.