Study guide Anatomy and Physiology I Exam IV April 26 2012 The Respiratory System Functional Anatomy of the Respiratory System 1 List the structures and functions of the nose nasal cavity and paranasal sinuses a Nose and Nasal Cavity i Structure 1 external nose surface area includes root area near 2 eyebrows bridge and dorsum nasi anterior margin the end is called the apex Inferior to the apex is a groove called the philtrum The nostrils are bound by a flared alae Structure is formed superiorly by nasal and frontal bones and laterally by maxiallary bones internal nasal cavity divided my a midline called the nasal septum formed by septal catrlidge and posteriorly by the volmer bone and perpendicular plate of the ethmoid bone Nasal cavity is continuous posteriorly witht eh pharynx through the posterior nasal apertures also called choanae funnels Roof of nasal cavity ethmoid and sphenoid bones of skill Floor palate separates nasal and oral cavities Anterior support is from the palatine bones and the processes of the maxillary bones called hard plate The unsupported posterior portion is a muscular soft plate Nasal cavity superior to nostrils is called the nasal vestibule which is lined with skin having sebaceous sweat glands with numerous hair follicles called vibrissae These hairs filter out all coarse particles from inspired air The olfactory epithelium muscoa lines the slitlike superior region and contains smell recetoprs and the respiratory muscoa which is pseudostratideid columnar epithelium contains scattered goblets cell that rest on a lamina propri supplied with muscoa and serous glands Note musous cells secrete mucus and serous cells secret a white watery fluid containing enzymes Each day about 1 liter mucus made contains lysozyme antibacterial enzyme and secrete defensins which are natural antibiotics to help remove microbes Also the high water content helps to humidify inspired air The ciliated cells of respiratory mucosa help move sheets of contaminated mucus to throat to be swallowed and digestive by stomach juices QuickTime and a decompressor are needed to see this picture Proturuding medially from lateral wall of nasal cavity is 3 mucosa covered projections the superior middle and inferior nasal conchae The groove inferior to each concha is a nasal meatus These are meant to increase surface area and enhance air turbulence These are used also to reclaim heat and moisture during exhalation provides an airway for respiration moistens and warms entering air filters and cleans inspired air serves as resonating chamber for speech and house olfactory receptors b Paranasal Sinuses surround nasal cavity Locate in frontal sphenoid ethmoid and maxiallary bones These lighten skull and warm moisten air The mucus they make flows to nasal cavity and the suctioning effect created by nose helps drain sinuses ii Funtcion Describe the structures of the pharynx larynx and trachea a Pharynx throat funnel shaped connects nasal cavity and mouth superiorly to larynx and inferiorly to esophagus 13 cm long from base of skull to level of 6th cervical vertebrae Three regions superiorly to inferiorly i Nasopharynx posterior to the nasal cavity inferior to 2 spheniod bone and superior to soft plate Lies where food enters body and serves as ONLY an air passage During swallowing the soft plate and uvula move superiorly to close off nasopharynx and prevent food from going to nasal cavity This is why when you laugh this flap moves and you can end up spraying stuff out of your nose The nasopharynx is continuous with the nasal cavity through the posterior nasal apertures It has psuedostraitifed epithelium that helps propel mucus Has a high posterior wall call pharyngeal tonsil which traps and destroys pathogens entering in air The pharyngotympanic auditory tubes that drain the middle ear cavities and allow middle ear pressure to equalize to atmospheric pressure this is open to the lateral walls of the nasopharynx A tubual tonsil ridge of pharynegeal mucosa arches over each of the openings b c of location tubal tonsils help to protect middle ear infections ii Oropharynx lies posterior to the oral cavity and is continuous with it through an archway called the isthmus of the fauces Lies inferiorly to the soft palate to epiglottis so both swallowed air and food pass through this Nasopharynx bends to oropharynx and epithelium changes to stratified squamos epithelium This allows for increase in friction and greater chemical trauma accompanying food passage The paired palatine tonsils lie embedded in the oropharyngeal mucosa of the lateral walls of the fauces The lingual tonsil covers the posterior surface of the tongue iii Laryngopharynx serves as passageway for food and is lined QuickTime and a decompressor are needed to see this picture with stratified squamous epithelium Lies directly posterior to the upright epiglottis and extends to the larynx where respiratory and digestive pathways diverge At this point the laryngopharynx is continuous with the esophagus posteriorly Esophagus conducts food and fluids to stomach and air enters larynx interiorly Food has the right of way during swallowing and air passage temporarily stops b Larynx voice box extends about 5 cm from the 3rd 6th cervical vertebra Superiorly attaches to hyoid bone and opens to laryngopharynx Inferiorly continuous with the trachea The 2 main functions are to provide a patent open airway and to act as a switching mechanism to route air and food to proper channels House vocal cords so third function is voice production i Framework is nine cartilages connect by membranes and ligaments Except for epiglottis all laryngeal cartilages are hyaline The large shield shaped thyroid cartilage is formed by fusion of 2 cartilage plates The midline laryngeal prominence adams apple usually larger in men Inferior to thyroid cartilage is the ring shaped cricoid cartilage atop and anchored to the trachea inferiorly 3 pairs of small cartilages form the lateral and posterior walls of the larynx arytenoids cuneiform and corniculate cartilages Most important is arytenoids cartilages b c they anchor the vocal folds The ninth cartilage is the epiglottis that is flexible and spoon shaped Composed of elastic cartilage almost completely covered in taste bud containing mucosa Extends from posterior tongue to its anchoring point on the rim of the thyroid cartilage ii When air flows into larynx inlet is wide open and the free edge of the epiglottis goes upward During
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