The nose is divided into the ________ and the __________
The external nose is formed by
hyaline cartilage and bones of the skull
The nasal cavity consists of two types of epithelium
The nasal cavity is surrounded by
Paranasal sinuses within the frontal, maxillary, sphenoid
Ethmoid bones that serve to lighten the skull, warm and moisten air, and produce mucus.
The pharynx connects the nasal cavity and mouth _________ to the larynx and esophagus ________.
The nasopharynx serves as only an _________, and contains the ___________, which traps and destroys airborne pathogens.
The oropharynx is an ____ and _____ passageway that extends inferiorly from the level of the soft palate to the epiglottis.
air and food
The laryngopharynx is an ____ and _____ passageway that lies directly posterior to the _______, extends to the ______, and is continuous inferiorly with the ________
air and food
The larynx attaches superiorly to the ________, opening into the______________, and attaches inferiorly to the ________
The larynx provides
an open airway, routes food and air into the proper passageways, and produces sound through the vocal cords.
The larynx consists of hyaline cartilages and the _________
thyroid, cricoid, paired arytenoid, corniculate, and cuneiform
Vocal ligaments form the core of _____________, the true vocal cords, which vibrate as air passes over them to produce sound.
The vocal folds and the medial space between them are called the
____________involves the intermittent release of expired air and the opening and closing of the glottis.
a behavior in which the glottis closes to prevent exhalation and the abdominal muscles contract, causing intra-abdominal pressure to rise.
_____________, or windpipe, descends from the larynx through the neck into
the mediastinum, where it terminates at the primary bronchi
the ____________ consists of right and left primary bronchi that enter each lung and diverge into secondary bronchi that serve each lobe of the lungs.
Secondary bronchi branch into several orders of ____________, which ultimately branch into ____________
As the conducting airways become smaller, the _____________ changes in character until it is no longer present in the bronchioles.
the _____________begins as the terminal bronchioles feed into respiratory bronchioles that terminate in alveolar ducts within clusters of alveolar sacs, which consist of alveoli.
The _____________ consists of a single layer of squamous epithelium surrounded by a basal lamina.
Interspersed among the type-I cells are septal cells that secrete
Alveoli are surrounded by __________, contain open ___________, and have
The lungs occupy all of the thoracic cavity except for the ___________; each lung is suspended within its own pleural cavity and connected to the mediastinum by vascular and bronchial attachments called the _________.
Each lobe of the lung contains a number of ___________________, each served by its own artery, vein, and tertiary bronchus.
Lung tissue consists largely of
air spaces and its stroma
The stroma of the lung is comprised mostly of
elastic connective tissue
There are two circulations that serve the lungs: the _________________ carries systemic blood to the lungs for oxygenation, and the________________ provide systemic blood to the lung tissue.
The lungs are innervated by _________________________________ that constrict or dilate the airways, as well as _____________.
parasympathetic and sympathetic motor fibers
visceral sensory fibers
The pleurae form a
thin, double-layered serosa
The ______________ covers the thoracic wall, superior face of the diaphragm, and continues around the heart between the lungs.
The ____________ covers the external lung surface, following its contours and fissures.
_________________________ is the pressure in the alveoli, which rises and falls during respiration, but always eventually equalizes with atmospheric pressure.
_________________ is the pressure in the pleural cavity. It also rises and falls during respiration, but is always about 4 mm Hg less than intrapulmonary pressure.
____________________ is a mechanical process causing gas flow into and out of the lungs according to volume changes in the thoracic cavity.
Boyle’s law states that
at a constant temperature, the pressure of a gas varies inversely with its volume.
During _______________, the diaphragm and intercostals contract, resulting in an increase in thoracic volume, which causes intrapulmonary pressure to drop below atmospheric pressure, and air flows into the lungs.
During _____________ accessory muscles of the neck and thorax contract, increasing thoracic volume beyond the increase in volume during quiet inspiration.
_____________ is a passive process that relies mostly on elastic recoil of the lungs as the thoracic muscles relax.
________________ is an active process relying on contraction of abdominal muscles to increase intra-abdominal pressure and depress the ribcage.
______________ is the friction encountered by air in the airways; gas flow is reduced as airway resistance increases.
Alveolar surface tension due to water in the alveoli acts to
draw the walls of the alveoli together, presenting a force that must be overcome in order to expand the lungs.
Lung compliance is determined by distensibility of lung tissue and the surrounding thoracic cage, and alveolar surface tension.
distensibility of lung tissue and the surrounding thoracic cage, and alveolar surface tension.
Respiratory volumes and specific combinations of volumes, called respiratory capacities, are used to
gain information about a person’s respiratory status
___________is the amount of air that moves in and out of the lungs with each breath during quiet breathing.
The____________ is the amount of air that can be forcibly inspired beyond the tidal volume.
inspiratory reserve volume
The ________________ is the amount of air that can be evacuated from the lungs after tidal expiration.
expiratory reserve volume
____________ is the amount of air that remains in the lungs after maximal forced expiration.
_____________ is the sum of tidal volume and inspiratory reserve volume, and represents the total amount of air that can be inspired after a tidal expiration.
_________________ is the combined residual volume and expiratory reserve volume, and represents the amount of air that remains in the lungs after a tidal expiration.
Functional residual capacity
_____________ is the sum of tidal volume, inspiratory reserve and expiratory reserve volumes, and is the total amount of exchangeable air.
The________________ is the volume of the conducting zone conduits, which is a volume that never contributes to gas exchange in the lungs.
anatomical dead space
___________ tests evaluate losses in respiratory function using a spirometer to distinguish between obstructive and restrictive pulmonary disorders.
Nonrespiratory air movements cause
movement of air into or out of the lungs, but are not related to breathing (coughing, sneezing, crying, laughing, hiccups, and yawning).
Dalton’s law of partial pressure states that
the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture
Henry’s law states t
when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure .
The relative proportions of gases in the alveoli reflect
gas exchange occurring in the lungs,
humidification of air by conducting passages,
and mixing of alveolar gas that occurs with each breath.
External respiration involves
O2 uptake and CO2 unloading from hemoglobin in red blood cells.
carbon dioxide is much more ______ than oxygen in the blood.
________________ ensures a close match between the amount of gas reaching the alveoli and the blood flow in the pulmonary capillaries.
The ____________ is normally very thin, and presents a huge surface area for efficient gas exchange.
Since molecular oxygen is poorly soluble in the blood, only _____is dissolved in plasma, while the remaining _____must be carried on
Up to ___ oxygen molecules can be reversibly bound to a molecule of hemoglobin—one oxygen on each iron.
The affinity of _________ for oxygen changes with each successive oxygen that is bound or released, making oxygen loading and unloading very efficient.
At higher plasma partial pressures of oxygen, hemoglobin unloads little oxygen, but if plasma partial pressure falls dramatically, such as during _________, much more oxygen can be unloaded to the tissues.
What influences hemoglobin saturation at a given partial pressure
Pressure of CO2
the amount of BPG in the blood
___________, secreted by lung and vascular endothelial cells, is carried on hemoglobin to the tissues where it causes vasodilation and enhances oxygen transfer to the tissues.
Nitric oxide (NO)
Carbon dioxide is transported in the blood in three ways:
7–10% is dissolved in plasma
20% is carried on hemoglobin bound to globins
70% exists as bicarbonate, an important buffer of blood pH.
The _________ encourages CO2 exchange in the lungs and tissues: when plasma partial pressure of oxygen and oxygen saturation of hemoglobin decrease, more CO2 can be carried in the blood.
The _________________________ of the blood is formed when CO2 combines with water and dissociates, producing carbonic acid and bicarbonate ions that can release or absorb hydrogen ions.
carbonic acid–bicarbonate buffer system
The ________________ contains the dorsal respiratory group, or inspiratory center, with neurons that act as the pacesetting respiratory group, and the ventral respiratory group, which functions mostly during forced breathing.
The _________________ within the pons modifies the breathing rhythm and prevents overinflation of the lungs through an inhibitory action on the medullary respiration centers.
pontine respiratory group
________________ on the part of the different respiratory centers is responsible for the rhythm of breathing.
___________________ respond to inhaled irritants by causing reflex constriction of the irritated passageways if the trachea or nasal cavity is irritated.
Pulmonary irritant reflexes
The inflation, or __________, reflex is activated by stretch receptors in the visceral pleurae and conducting airways, resulting in inhibition of inspiration.
The limbic system, strong emotions, and pain activate the
hypothalamus, which modifies respiratory rate and depth.
The ___________ can exert voluntary control over respiration by bypassing the medullary centers and directly stimulating the respiratory muscles.
__________________________ levels of PCO2 are the strongest stimuli influencing respiration; elevated PCO2, or ____________, causes an increase in rate and depth of breathing.
Plasma and cerebrospinal fluid
Blood PO2 affects breathing indirectly by
influencing chemoreceptor sensitivity to changes in PCO2.
___________________ monitor plasma PO2 and stimulate an increase in ventilation when PO2 drops below 60 mm Hg.
As ___________ declines, the respiratory system attempts to compensate by causing an increase in rate and depth of breathing.
During vigorous exercise, deeper and more vigorous respirations, called_____________, ensure that tissue demands for oxygen are met.
Three neural factors contribute to the change in respiration:
psychic stimuli, cortical stimulation of skeletal muscles and respiratory centers, and excitatory impulses to the respiratory areas from active muscles, tendons, and joints.
______________________ may result from a rapid transition from sea level to altitudes above 8000 feet.
Acute mountain sickness (AMS)
A long-term change from sea level to high altitudes results in ____________ of the body, including an increase in ventilation rate, lower than normal hemoglobin saturation, and increased production of erythropoietin.
_________________ are seen in patients that have a history of smoking, and result in progressive dyspnea, coughing and frequent pulmonary infections, and respiratory failure.
Chronic obstructive pulmonary diseases (COPD)
___________________ is characterized by permanently enlarged alveoli and deterioration of alveolar walls.
____________ results in excessive mucus production, as well as inflammation and fibrosis of the lower respiratory mucosa.
____________ is characterized by coughing, dyspnea, wheezing, and chest tightness, brought on by active inflammation of the airways
________________ is an infectious disease caused by the bacterium Mycobacterium tuberculosis and spread by coughing and inhalation
Most common type of cancer
.________________ arises in the epithelium of the bronchi, and tends to form masses that hollow out and bleed.
Squamous cell carcinoma
_______________ originates in peripheral lung areas as nodules that develop from bronchial glands and alveolar cells.
_______________ contains lymphocyte-like cells that form clusters within the mediastinum and rapidly metastasize.