Ch ;4 Structure and Function of the
(lungs, trachea, nose, alveoli, Larynx) of
the body ….study guide
A 3-dimensional visual of the respiratory system would be similar to an inverted tree if it
were hollow
Branches would be the bronchi
Leaves of the tree would be comparable to alveoli, with the microscopic sacs enclosed by
networks of capillaries
The passive transport process of diffusion is responsible forthe exchange of gases that occurs
during respiration
The respiratory tract is divided into upper and lower portions
The upper respiratory tract includes the nose, pharynx, and larynx
The lower respiratory tract contains the trachea, bronchial tree, alveoli, and lungs
The respiratory mucosa is a specialized membrane that lines the air distribution tubes in the
respiratory tree
Three types of epithelium arepresent in the respiratory mucosa
Ciliated pseudostratified epithelium lines most of the tract and produces mucus
Stratified squamous epithelium lines the nostrils, vocal folds, and pharynx; it serves a protective
function
Simple squamous epithelium lines the alveoli, and facilitates gas exchange
More than 125 mL of mucus is produced each day The respiratory mucosa forms a "mucous
blanket" over much of the respiratory mucosa
Mucus serves as an air purification mechanism by trapping inspired irritants such as dust and
pollen
The respiratory mucosa also supports what could be called the ciliary escalator; cilia on mucosal
cells beat in only one direction, moving mucus upward to the pharynx for removal
, A nasal septum separates the interior of the nose into two cavities, called nares or nostrils
Frontal, maxillary, sphenoidal, and ethmoidal sinuses of the skull drain into the nose
The nose warms and moistens inhaled air. It also houses the sense organs of smell
The pharynx or throat is about 12.5 cm (or 5 inches) long. It is divided into the
nasopharynx, oropharynx, and the laryngopharynx
The two nasal cavities, mouth, esophagus, larynx, and auditory tubes all have openings into
the pharynx
Pharyngeal tonsils and the openings of auditory tubes open into the nasopharynx
The tonsils are found in the oropharynx
The pharynx functions as a passageway for food and liquids, as well as a passageway for air
Nine pieces of cartilage form the framework of the last structure of the upper respiratory
tract, the larynx
The thyroid cartilage (also called the Adam's apple) is the largest of the nine pieces of cartilage
The epiglottis partially covers the opening into the larynx
Vocal cords stretch across the interior of the larynx
One of the larynx's functions is voice production
The other larynx's function is air distribution; like the pharynx, it serves as a passageway for air
to move to and from the lungs
The trachea is a tube about 11 cm (or 4.5 in) long and 2.5 cm (or 1 in) in diameter
The trachea extends from the larynx into the thoracic cavity
C-shaped rings of cartilage hold the trachea open, but allow for swallowing
The trachea functions as a passageway for air to move to and from the lungs
Blockage of the trachea occludes the airway and, if complete, causes death in minutes
In fact, tracheal obstruction causes more than 4,000 deaths annually in the United States
The trachea branches into right and left bronchi
Each bronchus branches into smaller and smaller tubes, eventually leading to bronchioles
Bronchioles end in clusters of microscopic alveolar sacs, the walls of which are made up of
alveoli
(lungs, trachea, nose, alveoli, Larynx) of
the body ….study guide
A 3-dimensional visual of the respiratory system would be similar to an inverted tree if it
were hollow
Branches would be the bronchi
Leaves of the tree would be comparable to alveoli, with the microscopic sacs enclosed by
networks of capillaries
The passive transport process of diffusion is responsible forthe exchange of gases that occurs
during respiration
The respiratory tract is divided into upper and lower portions
The upper respiratory tract includes the nose, pharynx, and larynx
The lower respiratory tract contains the trachea, bronchial tree, alveoli, and lungs
The respiratory mucosa is a specialized membrane that lines the air distribution tubes in the
respiratory tree
Three types of epithelium arepresent in the respiratory mucosa
Ciliated pseudostratified epithelium lines most of the tract and produces mucus
Stratified squamous epithelium lines the nostrils, vocal folds, and pharynx; it serves a protective
function
Simple squamous epithelium lines the alveoli, and facilitates gas exchange
More than 125 mL of mucus is produced each day The respiratory mucosa forms a "mucous
blanket" over much of the respiratory mucosa
Mucus serves as an air purification mechanism by trapping inspired irritants such as dust and
pollen
The respiratory mucosa also supports what could be called the ciliary escalator; cilia on mucosal
cells beat in only one direction, moving mucus upward to the pharynx for removal
, A nasal septum separates the interior of the nose into two cavities, called nares or nostrils
Frontal, maxillary, sphenoidal, and ethmoidal sinuses of the skull drain into the nose
The nose warms and moistens inhaled air. It also houses the sense organs of smell
The pharynx or throat is about 12.5 cm (or 5 inches) long. It is divided into the
nasopharynx, oropharynx, and the laryngopharynx
The two nasal cavities, mouth, esophagus, larynx, and auditory tubes all have openings into
the pharynx
Pharyngeal tonsils and the openings of auditory tubes open into the nasopharynx
The tonsils are found in the oropharynx
The pharynx functions as a passageway for food and liquids, as well as a passageway for air
Nine pieces of cartilage form the framework of the last structure of the upper respiratory
tract, the larynx
The thyroid cartilage (also called the Adam's apple) is the largest of the nine pieces of cartilage
The epiglottis partially covers the opening into the larynx
Vocal cords stretch across the interior of the larynx
One of the larynx's functions is voice production
The other larynx's function is air distribution; like the pharynx, it serves as a passageway for air
to move to and from the lungs
The trachea is a tube about 11 cm (or 4.5 in) long and 2.5 cm (or 1 in) in diameter
The trachea extends from the larynx into the thoracic cavity
C-shaped rings of cartilage hold the trachea open, but allow for swallowing
The trachea functions as a passageway for air to move to and from the lungs
Blockage of the trachea occludes the airway and, if complete, causes death in minutes
In fact, tracheal obstruction causes more than 4,000 deaths annually in the United States
The trachea branches into right and left bronchi
Each bronchus branches into smaller and smaller tubes, eventually leading to bronchioles
Bronchioles end in clusters of microscopic alveolar sacs, the walls of which are made up of
alveoli
