Ch. 10 Key Terms - Respiratory System
alveoli
Air sacs at the end of the smallest bronchioles. They are made of a single layer of tissue and are surrounded by blood capillaries, which is where oxygen and carbon dioxide are exchanged between the lungs and the blood.
bronchi
The two main tubes that the trachea divides into, one going to the right lung and one to the left. They carry air from the trachea into the lungs.
bronchioles
The smallest branches that the bronchi divide into within the lungs.
Cellular respiration
The process where cells use oxygen and nutrients to produce energy, water, and carbon dioxide.
cilia
Tiny, hairlike structures that filter inhaled air, trapping dust and other particles. They move the mucous layer to push these trapped particles toward the esophagus to be swallowed.
epiglottis
A special leaflike piece of cartilage that closes the opening into the larynx when swallowing. This action prevents food and liquids from entering the respiratory tract.
expiration
Also called exhalation, this is the process that occurs when the diaphragm and intercostal muscles relax, forcing air out of the lungs and air passages.
external respiration
The exchange of oxygen and carbon dioxide between the lungs and the bloodstream.
inspiration
Also called inhalation, this is the process of breathing in air. The diaphragm and intercostal muscles contract, enlarging the chest cavity and drawing air into the lungs.
internal respiration
The exchange of carbon dioxide and oxygen between the tissue cells and the bloodstream.
larynx
Also known as the voice box, it lies between the pharynx and the trachea. It contains the vocal cords, which vibrate as air leaves the lungs to produce sound.
lungs
The organs that contain the divisions of the bronchi and the alveoli. The right lung has three lobes, and the left lung has two.
nasal cavities
Two hollow spaces inside the nose, divided by the nasal septum. They are lined with a mucous membrane that warms, filters, and moistens air as it enters.
nasal septum
The wall of cartilage that divides the nose into the two nasal cavities.
nose
A part of the respiratory system with two openings (nostrils) through which air enters.
pharynx
Also known as the throat, it lies directly behind the nasal cavities and acts as a passageway for air as it leaves the nose.
pleura
The membrane or sac that encloses each lung. It has two layers with a fluid-filled space between them to prevent friction during breathing.
respiration
The overall process of inspiration (breathing in) and expiration (breathing out).
respiratory system
Consists of the lungs and air passages. It is responsible for taking in oxygen and removing carbon dioxide from the body.
sinuses
Cavities in the skull that surround the nasal area. They are lined with a mucous membrane that warms and moistens air and also provides resonance for the voice.
trachea
Also known as the windpipe, it is a tube that extends from the larynx to the center of the chest, carrying air between the pharynx and the bronchi.
ventilation
The process of breathing, which includes the two phases of inspiration and expiration.