LECTURE 8 upper respiratory tract Flashcards
components of upper respiratory tract
nose, external nares, vestibule, nasal cavity, oral cavity, pharynx
description of nose
only portion of respiratory tract externally visible; made of connective tissue, bone, hyaline cartilage
description of external nares
nostrils, openings for air to enter and exit the vestibule, face inferiorly (important for function)
function of nose
to keep bad things (dirt, dust, debris) from entering nasal cavity
description of vestibule
superior to nostrils, entranceway into nasal cavity, lined with skin (not wet mucosa)
components of skin of vestibule
sebaceous glands, sweat glands, hairs and vibrissae
functions of sebaceous glands of skin of vestibule
greasy secretion, collect dirt, lubricate, kill bacteria
functions of sweat glands of skin of vestibule
acidic, slows growth of bacteria
functions of hairs and vibrissae of skin of vestibule
physical filter, trap small particles of dirt, filter larger particles (insects, etc.)
functions of nasal cavity
provides airway for respiration, moistens and warms air, filters inhaled air, resonating chamber for speech, houses olfactory receptors
special features of nasal cavity
nasal septum and internal nares (choanae)
description of nasal septum of nasal cavity
divides cavity into right and left halves; formed from: vomer and perpendicular plate of ethmoid bone (suture), hyaline cartilage; covered with mucosa
description of internal nares of nasal cavity
aka choanae, 2 total, connect each half of nasal cavity with nasopharynx
roof of nasal cavity
ethmoid bone (cribform plate)
floor of nasal cavity
hard palate (also roof of oral cavity): maxillae bones (palatine process), palatine bones (horizontal plate); soft palate: skeletal muscle extending posteriorly, ends in uvula
lateral walls of nasal cavity
nasal bones, ethmoid bones (superior and middle nasal conchae), inferior nasal conchae, maxillae, palatine bones
posterior boundry of nasal cavity
nasopharynx
components of lining of nasal cavity
respiratory mucosa, olfactory mucosa
description of respiratory mucosa of nasal cavity
ciliated pseudostratified columnar epithelium (goblet cells - mucus secretion), lamina propria (mucus and serous cells), venous plexus (to filter and warm inhaled air), highly innervated (sneezing)
description of olfactory mucosa of nasal cavity
located at roof of nasal cavity, houses smell receptors, no goblet cells (no mucus secretion), cilia modified for olfaction
description of nasal conchae of nasal cavity
project medially from each lateral wall, made of bone, covered by same mucosa as rest of respiratory tract
3 pairs of nasal conchae
superior (ethmoid bone), middle (ethmoid bone), inferior (its own bone)
functions of nasal conchae of nasal cavity
create turbulence of air to increase: filtration, heating and moistening during inhalation; reclaim heat and moisture during exhalation; forces air to touch walls and mucosa; increase surface area (of mucosa)
description of paranasal sinuses of skull
air filled spaces within a skull bone, surround and are connected to nasal cavity, no olfactory receptors, lined by respiratory mucosa
paranasal sinuses of skull
frontal, maxillae, ethmoid, sphenoid
functions of paranasal sinuses of skull
perform same function as nasal cavity and lighten the skull
description of pharynx
connects the nasal cavity and mouth to larynx and esophagus, common passage for food and air, contains skeletal muscle (pharyngeal constrictors for voluntary swallowing), lined with mucosa, innervated by vagus and glossopharyngeal nerves
divisions of pharynx
nasopharynx, oropharynx, laryngopharynx
description of tonsils of pharynx
lymphoid organ (MALT: mucosa associated lymphoid tissue), form a ring around the entrance to pharynx
functions of tonsils of pharynx
remove pathogens, process antigens, set up immune response (minor role)
groups of tonsils of pharynx
palatine, lingual, pharyngeal (adenoids: inflamed pharyngeal tonsil), tubal
description of nasopharynx of pharynx
only an air passageway, ciliated pseudostratified epithelium, closed off during swallowing by soft palate and uvula, most superior level of pharynx
location of nasopharynx of pharynx
posterior to nasal cavity, interior to sphenoid bone, superior to level of soft palate
contents of nasopharynx of pharynx
pharyngeal tonsils (adenoids), tubal tonsils
description of oropharynx of phaynx
passageway for food and air, stratified squamous epithelium, middle level of pharynx
location of oropharynx of phaynx
posterior to oral cavity, inferior to level of soft palate, superior to level of epiglottis
contents of oropharynx of pharynx
palatine tonsils, lingual tonsils
description of laryngopharynx of pharynx
passageway for food and air (moves air to larynx, forces food to esophagus if epiglottis has close laryngeal inlet), stratified squamous epithelium, most inferior level of pharynx
location of laryngopharynx of pharynx
posterior to larynx, continuous with esophagus and larynx
contents of laryngopharynx of pharynx
contains no tonsils
description of larynx
part of lower respiratory tract, extends from C4-C6, lined with mucosa, superior part lined with stratified squamous epithelium (consistent with laryngopharynx), inferior part lined with ciliated pseudostratified epithelium, innervated by vagus nerve, made of mostly hyaline cartilge, has lumen for air, contains vocal cords
attachments of larynx
hyoid bone superiorly, continuous with trachea inferiorly
functions of larynx
vocalization (“voice box”), provides open airway, puts food into esophagus and keeps it out of respiratory tract
description of cartilages of larynx
9 cartilages, all hyaline cartilage except epiglottis (elastic cartilage), cartilages connected to each other by membranes and ligaments
cartilages of larynx
thyroid, cricoid, epiglottis, 2 arytenoid, 2 corniculate, 2 cuneiform
description of epiglottis of larynx
projects superiorly from anterior wall of laryngeal inlet to level of base of tongue, elastic cartilage, closes off laryngeal inlet during swallowing, sometimes has tastebuds
description of thyroid cartilage of larynx
largest cartilage of larynx, shield shaped, formed by 2 plates (fused midline), laryngeal prominence (adam’s apple), sexually dismorphic (larger in males)
description of cricoid cartilage of larynx
inferior to thyroid cartilage of larynx, superior to trachea, forms a complete ring
description of vocal cords
located in larynx, connect to arytenoid and thyroid cartilages, thickening of mucosa, mucosal folds formed by vocal ligaments, composed of elastic fibers
function of vocal cords
vibrate as air passes over them during exhalation: force of air = volume, length and tension of folds = pitch, muscles move cords to produce sound
description of false vocal cords
vestibular folds, superior to true vocal cords, no role in voice production, more protective role
