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139 Cards in this Set
- Front
- Back
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what are the functions of the "conducting portion" of the respiratory system?
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conditions the air by warming, moistening, and filtering it
(this optimizes gas exchange in the lungs) |
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what is included in the conducting portion of the respiratory system?
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nasal cavity
nasopharynx larynx trachea bronchi bronchioles |
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what is the separation point for conducting portion and respiratory portion of the respiratory system?
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terminal bronchioles (last part of conducting portion)
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what is included in the respiratory portion of the respiratory system?
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respiratory bronchioles
alveolar ducts alveolar sacs alveoli |
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what is included in the ventilating mechanism of the respiratory system?
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diaphragm
rib cage intercostal muscles abdominal muscles elastic connective tissue in lungs |
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from where is the epithelia of the respiratory tract derived?
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endoderm
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what are the wall layers of the respiratory tract?
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respiratory epithelium
lamina propia glands cartilage smooth muscle adventitia |
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what are the types of epithelium cells in the respiratory system?
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ciliated columnar cells
goblet (mucous) cells basal (stem) cells brush cells small granule cells |
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what are brush cells?
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cells with microvilli, not cilia, and afferent nerve endings, which act as sensory receptors
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what type of cell is a small granule cell?
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endocrine
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what are the anterior openings of the nasal cavity called?
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nares
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what is the vestibule of the nasal cavity?
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most anterior portion of the nasal cavity
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what type of epithelium lines the vestibule of the nasal cavity?
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non-keratinized stratified squamous epithelium
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what are vibrissae?
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thick short hairs in the vestibule of the nasal cavity which filter out large particles
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what part of the respiratory system contains sebaceous glands? what do they produce?
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vestibule of the nasal cavity
produce sebum |
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what type of epithelium lines the respiratory segment of the nasal mucosa?
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ciliated pseudostratified columnar epithelium
(aka respiratory epithelium) |
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what type of epithelium lines the olfactory segment of the nasal mucosa?
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specialized type of pseudostratified columnar epithelium
(aka olfactory epithelium) |
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what are conchae?
what is their purpose? |
shelf-like bony projections from lateral walls of nasal mucosa
increase surface area for warming and moistening of air create turbulence which slows air and allows particles to drop out |
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what is turbulent precipitation?
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the use of turbulence (in a gas or liquid) to cause particles to fall out of solution
ex. conchae in nasal cavity causing dust particles to drop out of air |
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what is important about the very vascular lamina propia of the nasal mucosa?
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every 20-30 minutes, the air flow switches between two sides
lamina propia becomes distended during "stuffy" nose venous plexuses of inferior concha are common site of nosebleed |
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what causes the alternation of air flow between nasal fossae?
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venous plexuses in conchal mucosa engorge with blood, restricting air flow on that side
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where is the olfactory sense located in the respiratory system?
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along dorsal roof of nasal cavity
olfactory epithelium has receptors for smell, and olfactory neurons |
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why is the olfactory epithelium yellowish-brown?
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has a high concentration of lipofuscin pigment
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what type of neurons are olfactory cells?
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bipolar neurons
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where are the cilia of olfactory cells?
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extend from apical pole of neurons along epithelial surface
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what coats the epithelial surface of the olfactory segment of the nasal mucosa?
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serous secretion from Bowman's glands
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what is formed by the axons of the olfactory cells?
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olfactory nerve (CN I)
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where does the olfactory nerve enter the brain cavity?
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through cribiform plate
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what type of cells are the supporting cells of the nasal mucosa?
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tall, columnar cells, with microvilli and a prominent terminal web
they provide metabolic and physical support for the neurons in the olfactory epithelium |
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where are basal cells located in the nasal mucosa?
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resting on basal lamina, but not extending to the surface
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what is the function of basal cells in the nasal mucosa?
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to divide and differentiate into both supporting and olfactory cells
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how often is olfactory epithelium replaced?
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once every 2-4 weeks
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where are the Bowman's glands located?
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along the dorsal roof of the nasal cavity, in the lamina propia
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what are Bowman's glands?
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serous glands with simple cuboidal ducts
their secretion traps and solubilizes oderiferous substances |
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what is odorant binding protein (OBP)?
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a protein which is contained in the serous secretion of the Bowman's glands which creates a complex with an odorant molecule as well as a receptor on the modified cilium of the olfactory cells
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what is another name for seasonal rhinitis?
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hayfever
allergic rhinitis |
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what are the symptoms of allergic rhinitis?
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irritation of nose
congestion or watering of nose itchy eyes itchy ears itchy throat sneezing |
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what causes seasonal rhinitis?
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exaggerated response to an environmental trigger (like pollen) which results in inflammation of the lining of the nose
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what is rhinitis?
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inflammation of the lining of the nose
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what is Atopy?
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syndrome of over-active immune responses, in which individuals are more likely to develop allergic rhinitis, asthma, and eczema
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what is different in patients with atopy?
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elevated levels of IgE antibody in their blood
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what are paranasal sinuses?
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blind cavities in the frontal, maxillary, ethmoid, and sphenoid bones, which communicate with the nasal cavities through small openings (called ostia)
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what happens in sinusitis?
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small openings (ostia) of the paranasal sinuses become obstructed
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what type of epithelium lines the paranasal sinuses?
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ciliated pseudostratified columnar epithelium (respiratory epithelium)
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what type of epithelium lines the nasopharynx?
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ciliated pseudostratified columnar epithelium (respiratory epithelium)
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where is the nasopharynx?
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connecting nasal cavity with larynx
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where do the auditory tubes empty?
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into the nasopharynx
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where are the pharyngeal tonsils contained?
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in the nasopharynx
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where is the larynx located?
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between the pharynx and the trachea
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what are the functions of the larynx?
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produces sound
closes the trachea during swallowing |
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what supports the wall of the larynx?
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thyroid hyaline cartilage
cricoid hyaline cartilage epiglottis |
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what is the epiglottis?
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a thin leaf of elastic cartilage that projects over the lumen of the anterior larynx
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where do skeletal muscles that control the vocal apparatus attach?
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laryngeal cartilages
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what causes the epiglottis to close over the laryngeal opening during swallowing?
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backward motion of the tongue
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what causes the epiglottis to reopen and maintain the airway?
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elastic cartilage within the epiglottis
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what is the function of the epiglottis?
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covers the laryngeal opening, directing food away and into the esophagus
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what are the false vocal cords (ventricular folds/vestibular vocal cords)?
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upper pair of folds that extends across the laryngeal cavity, not involved in noise production
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what type of epithelium covers the false vocal cords (ventricular folds/vestibular vocal cords)?
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respiratory epithelium
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what is the function of false vocal cords?
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create sound resonance
(DO NOT PARTICIPATE IN PHONATION) |
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what type of epithelium covers the true vocal cords?
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stratified squamous epithelium
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what is contained in the true vocal cords?
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vocal ligament
vocalis muscle |
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what type of fiber is rich in the vocal ligament?
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elastic fibers
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what type of muscle is the vocalis muscle?
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skeletal muscle
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how do the vocal cords produce sound?
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air forced through the larynx causes vocal cords to vibrate
the vocalis muscle regulates the tension of the cords, while other muscles control the shape of the laryngeal lumen degree of tension in cords alters the pitch of the sound modification by tongue, palate, and lips produce speech |
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what is the name for the v-shaped opening formed by the vocal cords at rest?
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glottis
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what is pharyngitis? viral pharyngitis? bacterial pharyngitis?
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inflammation of the throat (mainly causing a sore throat)
...caused by a virus ...caused by a bacteria (generally streptococcus bacteria) like strep throat |
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what are the four best predictors of strep throat?
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lack of cough
swollen and tender anterior cervical lymph nodes marked tonsillar exudates fever |
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what are the four layers of the tracheal wall?
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mucosa
submucosa hyaline cartilage and perichondrium adventitia |
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what is included in the mucosa of the trachea?
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respiratory epithelium
thick basement membrane lamina propria elastic lamina |
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what is in the submucosa of the trachea?
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connective tissue
seromucous glands blood vessels nerves |
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what bridges the open end of the 16-20 C-shaped cartilagenous rings in the trachea?
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fibroelastic filament - permits widening of trachea during inhalation
trachealis muscle - smooth muscle which constricts tracheal lumen during coughing and forced expiration |
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which direction do the open ends of the cartilagenous rings of the trachea face?
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posteriorly
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what does the trachealis muscle do?
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constricts tracheal lumen during coughing and forced expiration
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what is the histological appearance of the primary bronchi?
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mucosa
submucosa hyaline cartilage and perichondrium adventitia |
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what supports the secondary and tertiary bronchi?
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irregular-shaped cartilage plates
spiraling smooth muscle bundles which separate the lamina propria from the submucosa |
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what are cartilage plates?
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irregularly-shaped support structures of secondary and tertiary bronchi, which become smaller and less numerous as the divisions get further into the lungs
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where are the seromucous glands in the bronchial wall?
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in the submucosa
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what is contained in the respiratory epithelium of the bronchial wall?
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ciliated epithelial cells
goblet cells |
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what are the four important aspects of the wall of a bronchs?
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cartilage plates
bronchial glands smooth muscle (which spirals and bundles) branch of the pulmonary artery |
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in a tertiary bronchus, what features are easily noted?
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few cartilagenous plates
smooth muscle totally encircles the lumen glands are sparse submucosa blends with surrounding adventitia there are numerous aggregations of lymphocytes |
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what are the important features of bronchioles?
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lack glands in submucosa
contain smooth muscle contain no cartilagenous plates Kulchitsky cells are scattered in epithelium various epithelium along length clara cells |
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what are Kulchitsky cells?
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neuroendocrine cells in the epithelium of bronchioles which produce and secrete serotonin
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what type of epithelial cells line larger bronchioles?
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ciliated columnar cells
goblet cells |
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what type of epithelial cells line mid-size bronchioles?
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ciliated columnar cells
Clara cells (no goblet cells) |
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what type of epithelial cells line terminal bronchioles?
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mostly Clara cells
some ciliated cells (no goblet cells) |
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what type of cells are Clara cells?
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non-ciliated epithelial cells with a rounded apex
appear like protein-secreting cells at EM level |
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what is the function of Clara cells?
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to secrete a non-sticky proteinaceous compound (rather than mucous) to maintain the airway in the smallest bronchioles
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what interrupts the epithelium of respiratory bronchioles?
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thin-walled sacs called alveoli
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what are alveolar ducts?
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distal extensions of the respiratory bronchioles
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what is in the epithelial lining of alveolar ducts?
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small knobs of smooth muscle covered by non-ciliated cuboidal cells
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what is the purpose of the smooth muscle in the epithelium of alveolar ducts?
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to provide structural support
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what are alveolar sacs?
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clusters of alveoli
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what is absent in the knobs of alveolar sacs (compared to alveolar ducts)?
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smooth muscle
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what are alveoli?
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pouch-like evaginations which form air sacs in the lung, which have thin walls that oxygen and carbon dioxide can easily diffuse between
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what type of epithelium lines alveoli?
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simple squamous epithelium
(type I and type II alveolar cells) |
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why must the lung have fibroblasts?
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to create the elastic fibers which allow it to stretch
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what are pneumocytes?
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alveolar cells
there are type I and type II |
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what type of alveolar cell covers most of the surface of alveoli (95%)?
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type I alveolar cell
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what is important about type I alveolar cells?
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cover 95% of alveolar surface
extremely thin cytoplasm tight junctions with adjacent cells not able to divide |
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what is important about type II alveolar cells?
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cuboidal shape which bulges into alveoli
able to divide and regenerate tight junctions with adjacent cells secrete pulmonary surfactant |
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what are lamellar bodies in type II pneumocytes?
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granules which fill the cytoplasm and contain pulmonary surfactant
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what is pulmonary surfactant composed of?
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phosphatidylcholine
other phospholipids |
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what is the function of pulmonary surfactant when exocytosed?
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form a thin layer along alveolar surface, permitting alveoli to expand easily during inspiration, and preventing their collapse during expiration
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what are dust cells?
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alveolar macrophages
phagocytic cells residing along the alveolar surface and in the alveolar septum |
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what is the function of alveolar macrophages?
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remove inhaled dust, bacteria and other particulate material
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what happens to the alveolar macrophages which have been filled with debris?
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migrate to bronchioles, carried upper airways via ciliary action, and expelled by coughing
remain in connective tissue of lung for life of individual (e.g. smoker's lung) |
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what separates alveoli from one another?
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alveolar septa
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what is contained within alveolar septa?
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blood capillaries
connective tissue |
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what are the layers of the air-blood barrier?
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type I alveolar cells and layer of surfactant lining alveolar sac
fused basal laminae of endothelial cells and type I pneumocytes endothelial cells of continuous capillaries within alveolar septum |
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what is found between basal laminae in thick regions of the alveolar septum?
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connective tissue cells
connective tissue fibers (collagen and elastic fibers) |
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where does most gas exchange occur?
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thin portions of the septa of alveoli
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what occurs in the thick regions of the septa of alveoli?
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fluid in alveoli is absorbed and transported to lymphatic vessels
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where are alveolar pores located?
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thin regions of septa of alveoli
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what are pores of Kohn?
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alveolar pores
pores in the thin regions of the septa of alveoli, which allow pressure to equalize between alveoli |
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what supports alveoli?
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elastic fibers
reticular fibers |
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what is chronic obstructive pulmonary disease (COPD)?
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disease state characterized by limitation of airflow
(not fully reversible, and gets progressively worse) includes emphysema and chronic bronchitis |
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what type of diseases are emphysema and chronic bronchitis?
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chronic obstructive pulmonary disease (COPD)
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what causes COPD?
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noxious particles or gas (smoking) which triggers an abnormal inflammatory response in the lung
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what is emphysema?
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loss of elasticity in lung tissue caused by the breakdown of elastic fibers and alveolar walls by an inflammatory response
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what type of cells are involved in the inflammatory response associated with emphysema?
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neutrophils (PMNs)
macrophages |
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what is the hypothesis for the cause of emphysema?
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alpha1-antitrypsin contributes to elastic damage
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where is alpha1-antitrypsin produced?
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liver
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what happens during exhalation in emphysema?
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small airspaces collapse, trapping air in the lung
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what are the three types of emphysema? which are most common?
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centrilobular and centroacinar (most common)
panacinar (rare - only 2%) |
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what is asthma?
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chronic inflammatory disorder of the airways in which bronchioles constrict
(at least partly reversible) |
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what are the three problems associated with asthma?
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episodic bronchoconstriction
airway remodeling due to chronic inflammation increased mucus secretion |
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what causes the episodic bronchoconstriction associated with asthma?
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hyperreactivity to stressors including allergens, cold and smoke
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what is histollogically seen in severe asthma patients?
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reduction in bronchial diameter due to bronchospasms
mucosal edema excess mucus production basement membrane fibrosis eosinophilic inflammation smooth muscle hyperplasia |
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on what is the transition from placental to pulmonary oxygenation of blood dependent?
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rapid removal of fetal lung fluid from developing alveoli
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what creates lung fluid in the fetal lung?
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chloride channels in type I and type II alveolar cells
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what triggers the clearing of fetal lung fluid at birth?
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beta-adrenergic autonomic nerve fibers, which stimulate sodium channels and possibly aquaporin4 channels
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what are the most common causes of neonatal respiratory distress syndrome?
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hyaline membrane disease in premature infants
aspiration of meconium in full-term infants |
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what is meconium?
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fetal poop
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what is considered a premature infant?
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born after less than 32 weeks of gestation
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what causes hyaline membrane disease?
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insufficient lung surfactant protein
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what arteries accompany the bronchial tree?
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branches of the pulmonary artery
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why do branches of the pulmonary artery have such thin walls?
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there is very low blood pressure
(25mmHg systolic, 5mmHg diastolic) |
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where is the best developed capillary network in the body?
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lungs
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what is serosa?
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visceral pleura
mesothelium and underlying connective tissue which covers the lungs (and heart) |
