67 Glossary: The Respiratory System
Glossary
ala (plural = alae) small, flaring structure of a nostril that forms the lateral side of the nares
alar cartilage cartilage that supports the apex of the nose and helps shape the nares; it is connected to the septal cartilage and connective tissue of the alae
alveolar duct small tube that leads from the terminal bronchiole to the respiratory bronchiole and is the point of attachment for alveoli
alveolar macrophage immune system cell of the alveolus that removes debris and pathogens
alveolar pore opening that allows airflow between neighboring alveoli
alveolar sac cluster of alveoli
alveolus small, grape-like sac that performs gas exchange in the lungs
apex tip of the external nose
bronchial tree collective name for the multiple branches of the bronchi and bronchioles of the respiratory system
bronchoconstriction decrease in the size of the bronchiole due to contraction of the muscular wall
bronchodilation increase in the size of the bronchiole due to contraction of the muscular wall
bridge portion of the external nose that lies in the area of the nasal bones
bronchiole branch of bronchi that are 1 mm or less in diameter and terminate at alveolar sacs
bronchus tube connected to the trachea that branches into many subsidiaries and provides a passageway for air to enter and leave the lungs
cardiac notch indentation on the surface of the left lung that allows space for the heart
conducting zone region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange
cricoid cartilage portion of the larynx composed of a ring of cartilage with a wide posterior region and a thinner anterior region; attached to the esophagus
dorsum nasi intermediate portion of the external nose that connects the bridge to the apex and is supported by the nasal bone
epiglottis leaf-shaped piece of elastic cartilage that is a portion of the larynx that swings to close the trachea during swallowing
external nose region of the nose that is easily visible to others
fauces portion of the posterior oral cavity that connects the oral cavity to the oropharynx
fibroelastic membrane specialized membrane that connects the ends of the C-shape cartilage in the trachea; contains smooth muscle fibers
glottis opening between the vocal folds through which air passes when producing speech
hilum concave structure on the mediastinal surface of the lungs where blood vessels, lymphatic vessels, nerves, and a bronchus enter the lung
laryngeal prominence region where the two lamina of the thyroid cartilage join, forming a protrusion known as “Adam’s apple”
laryngopharynx portion of the pharynx bordered by the oropharynx superiorly and esophagus and trachea inferiorly; serves as a route for both air and food
larynx cartilaginous structure that produces the voice, prevents food and beverages from entering the trachea, and regulates the volume of air that enters and leaves the lungs
lingual tonsil lymphoid tissue located at the base of the tongue
lung organ of the respiratory system that performs gas exchange
meatus one of three recesses (superior, middle, and inferior) in the nasal cavity attached to the conchae that increase the surface area of the nasal cavity
naris (plural = nares) opening of the nostrils
nasal bone bone of the skull that lies under the root and bridge of the nose and is connected to the frontal and maxillary bones
nasal septum wall composed of bone and cartilage that separates the left and right nasal cavities
nasopharynx portion of the pharynx flanked by the conchae and oropharynx that serves as an airway
oropharynx portion of the pharynx flanked by the nasopharynx, oral cavity, and laryngopharynx that is a passageway for both air and food
palatine tonsil one of the paired structures composed of lymphoid tissue located anterior to the uvula at the roof of isthmus of the fauces
paranasal sinus one of the cavities within the skull that is connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consists of frontal, maxillary, sphenoidal, and ethmoidal sinuses
parietal pleura outermost layer of the pleura that connects to the thoracic wall, mediastinum, and diaphragm
pharyngeal tonsil structure composed of lymphoid tissue located in the nasopharynx
pharynx region of the conducting zone that forms a tube of skeletal muscle lined with respiratory epithelium; located between the nasal conchae and the esophagus and trachea
philtrum concave surface of the face that connects the apex of the nose to the top lip
pleural cavity space between the visceral and parietal pleurae
pleural fluid substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing
pulmonary artery artery that arises from the pulmonary trunk and carries deoxygenated, arterial blood to the alveoli
pulmonary plexus network of autonomic nervous system fibers found near the hilum of the lung
pulmonary surfactant substance composed of phospholipids and proteins that reduces the surface tension of the alveoli; made by type II alveolar cells
respiratory bronchiole specific type of bronchiole that leads to alveolar sacs
respiratory epithelium ciliated lining of much of the conducting zone that is specialized to remove debris and pathogens, and produce mucus
respiratory membrane alveolar and capillary wall together, which form an air-blood barrier that facilitates the simple diffusion of gases
respiratory zone includes structures of the respiratory system that are directly involved in gas exchange
root region of the external nose between the eyebrows
thyroid cartilage largest piece of cartilage that makes up the larynx and consists of two lamina
trachea tube composed of cartilaginous rings and supporting tissue that connects the lung bronchi and the larynx; provides a route for air to enter and exit the lung
trachealis muscle smooth muscle located in the fibroelastic membrane of the trachea
true vocal cord one of the pair of folded, white membranes that have a free inner edge that oscillates as air passes through to produce sound
type I alveolar cell squamous epithelial cells that are the major cell type in the alveolar wall; highly permeable to gases
type II alveolar cell cuboidal epithelial cells that are the minor cell type in the alveolar wall; secrete pulmonary surfactant
vestibular fold part of the folded region of the glottis composed of mucous membrane; supports the epiglottis during swallowing
visceral pleura innermost layer of the pleura that is superficial to the lungs and extends into the lung fissures