Respiratory System

The respiratory system is responsible for gas exchange in the body, particularly oxygen intake and carbon dioxide removal.

• Nose and nasal cavity

Main Components

• Pharynx (throat)
• Larynx (voice box)
• Trachea (windpipe)
• Bronchi and bronchioles
• Lungs and alveoli
• Diaphragm

Process of Breathing

• Inhalation (breathing in): Diaphragm contracts and flattens, intercostal muscles contract, chest cavity expands, air pressure decreases, and air flows in
• Exhalation (breathing out): Diaphragm relaxes, intercostal muscles relax, chest cavity decreases in volume, air pressure increases, and air flows out

Gas Exchange

Occurs in the alveoli of the lungs:

• Oxygen diffuses from alveoli into the bloodstream
• Carbon dioxide diffuses from the bloodstream into the alveoli
• Facilitated by the large surface area of alveoli and thin membranes

Circulatory System

The circulatory system transports nutrients, gases, hormones, blood cells, and waste products throughout the body.