Respiratory System Notes
Overview
The respiratory system is responsible for the exchange of gases (oxygen and carbon
dioxide) between the body and the environment. It consists of the upper and lower
respiratory tracts, lungs, and respiratory muscles.
Components
1. Upper Respiratory Tract
○ Nose/Nasal Cavity: Filters, warms, and humidifies the air.
○ Pharynx (Throat): Passageway for air and food; connects the nasal cavity
to the larynx.
○ Larynx (Voice Box): Contains vocal cords; routes air and food into proper
channels.
2. Lower Respiratory Tract
○ Trachea (Windpipe): A tube that connects the larynx to the bronchi; lined
with cilia and mucus to trap particles.
○ Bronchi: Two main branches (right and left) that lead from the trachea into
the lungs.
○ Bronchioles: Smaller branches of the bronchi within the lungs.
3. Lungs
○ Alveoli: Tiny air sacs where gas exchange occurs. Surrounded by
capillaries.
○ Pleura: Double-layered membrane surrounding the lungs, reducing friction
during breathing.
4. Respiratory Muscles
○ Diaphragm: A dome-shaped muscle at the bottom of the thoracic cavity;
main muscle of respiration.
○ Intercostal Muscles: Located between the ribs; assist with breathing.
Functions
1. Gas Exchange:
Overview
The respiratory system is responsible for the exchange of gases (oxygen and carbon
dioxide) between the body and the environment. It consists of the upper and lower
respiratory tracts, lungs, and respiratory muscles.
Components
1. Upper Respiratory Tract
○ Nose/Nasal Cavity: Filters, warms, and humidifies the air.
○ Pharynx (Throat): Passageway for air and food; connects the nasal cavity
to the larynx.
○ Larynx (Voice Box): Contains vocal cords; routes air and food into proper
channels.
2. Lower Respiratory Tract
○ Trachea (Windpipe): A tube that connects the larynx to the bronchi; lined
with cilia and mucus to trap particles.
○ Bronchi: Two main branches (right and left) that lead from the trachea into
the lungs.
○ Bronchioles: Smaller branches of the bronchi within the lungs.
3. Lungs
○ Alveoli: Tiny air sacs where gas exchange occurs. Surrounded by
capillaries.
○ Pleura: Double-layered membrane surrounding the lungs, reducing friction
during breathing.
4. Respiratory Muscles
○ Diaphragm: A dome-shaped muscle at the bottom of the thoracic cavity;
main muscle of respiration.
○ Intercostal Muscles: Located between the ribs; assist with breathing.
Functions
1. Gas Exchange:
