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20 Cards in this Set
- Front
- Back
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What are the functions of the respiratory system?
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conduction of air
conditioning of air gaseous exchange speech olfaction endocrine immune response |
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What air passages make up the conducting portion of the respiratory system?
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nasal cavity
nasopharynx epiglottis trachea main stem bronchi small bronchi (terminal) bronchioles NO GAS EXCHANGE! |
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How do infants breath?
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Infants are obligate nasal breathers
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What epithelia lines the nasal passages?
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Nasal passages are lined by pseudostratified ciliated columnar epithelium - the type of epithelium so characteristic of he proximal respiratory. Also contains some goblet cells.
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What lies in the superior aspect of each nasal cavity?
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The olfactory mucosa, which is the smell organ: the beginning of the first cranial nerve (Olfactory). These cells are lost every 30 days!
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What do submucosal vessels do?
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-play a major role in warming of inhaled air
-air also moistened by mucus -trap & solvent for odoriferous substances, which must be solubilized in order to be smelled |
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Why must O2 given through a nasal cannula be humidified?
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Nasal oxygen bubbled through water to prevent damaged to mucosa - as flow rate is increased, the possibility for dehydration damage increases, which is intolerable to patient.
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What is Waldeyer's Ring?
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Associated lymphoid tissue of the nasopharynx forming nasopharyngeal tonsils and adenoids with clefts that form a perfect growth area for pathogens.
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What cell types are in respiratory epithelium?
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Goblet cell
Ciliated columnar cells non ciliated columnar cells (have microvilli) basal cells (stem cell) small granule cell (secrete catecholamines) Sits on lamina propria - loose connective tissue with macrophages, nerves, vessels, etc... |
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How to tell true vocal cords from false?
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True vocal cords are covered by wet non-keratinized squamous epithelium, connected to vocalis (striated skeletal) muscle.
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Description of trachea histology
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Lined by pseudostratified ciliated columnar epithelium
Contains Brush cells - columnar cells with blunt microvilli, in contact with nerve ending/considered receptor cell Small granule cells - similar to enteroendocrine Distinct basement membrane Typical lamina propria Elastic membrane at interface between lamina propria and submucosa Submucosa contains seromucous glands "C"-shaped band of hyaline cartilage with opening facing posteriorly lies deep to submucosa Outside of perichondrium is a typical adventitia |
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What keep the trachea patent?
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C-shaped hyaline cartilage rings
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How do bronchi compared to the trachea histologically?
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Histologically similar except for:
-cartilaginous rings are replaced with PLATES -variable amounts of smooth muscle with elastic fibers are arranged in longitudinal bands -Epithelium is pseudostratified in the larger bronchi & progressively diminishes in thickness in peripheral branches |
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Describe bronchi muscles in asmtha
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Bronchi muscles are hypertrophied in asthma
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Describe epithelium of bronchioles
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Cell are usually ciliated although progressively lower in height from ciliated columnar, ciliated cuboidal, non-ciliated cuboidal...
Basal, intermediate, goblet, and neuroendocrine cells Euroendocrine are most numerous in the fetal lungs - typical granules, secrete active peptides bombesin & serotonin Cells of origin of "oat" cell ca (small cell) undifferentiated Absence of cartilage Abundant Smooth Muscle Absence of seromucous glands |
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What is a Clara cell?
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Produces surface active substance which aid in the maintenance of the patency of the bronchiole. Possesses smooth ER, rough ER, Golgi, vacuoles; secretes anti-proteases, oxidases; metabolize via CytP450 system.
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Describe the histology of the terminal bronchioles.
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No goblet cells
Some ciliated cuboidal cells Clara cells increase as ciliated cells decrease |
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Describe respiratory bronchioles
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Distal to terminal bronchioles, the lung is composed of lobules (central respiratory bronchiole branching to alveolar duct and sacs). THIS IS THE RESPIRATORY DIVISION.
Smooth muscle is present between the alveoli, Clara cells are more numerous |
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Describe alveoli
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The structural and functional unit of the lung
150-400 million in each normal lung Septum btwn adjacent alveoli contained capillaries supported by elastic and reticular fibers Has pores of Kohn through which adjacent alveoli share air - pathology e.g. spread of bacterial pneumonia |
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Cell types of alveoli and functions
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Type I pneumocytes - 40% of alveolar cells, but 90-95% of surface area. These don't divide.
Flattened squamous cells joined by tight junctions, sit on basement membrane which may be fused with basal lamina of nearby capillary endothelial cells -- good for gas exchange Type II pneumocyte: 60% of cell population but occupy only 5-10% of alveolar surface area - round shaped cells that look like typically secretory cells - nuclei are round and dark staining, cytoplasm contains mito, RER, SER, and lamellar bodies - lamellar bodies composed of phospholipid, protein, & glycosaminoglycans & form the basis for pulmonary surfactant - surfactant extruded through microvilli on luminal surface |
