upper airway and digestive tract Flashcards
nasal cavities DIAGRAM
have superior, middle and inferior conchae, wihth superior, middle and inferior meatuses (inferior is beneath inferior conchae) they warm/humidify air, trap pathogens and allow drainage of liquid from sinuses (if liquid in sinuses, could go into cranial cavity= dangerous)
bones in nasal cavity DIAGRAM
nasal bone maxilla next to lacrimal bone palatine bone next to sphenoid bone
innervation of nasal cavity
trigeminal nerve (main nerve for sensation of face)- V1 anteriorly, V2 posteriorly olfactory nerve for smell facial nerve for glands eg lacrimal gland SNS nerves (those going above ie to head all come from T1)- for VCSM
blood supply of nasal cavity
branches of internal and external carotid venous supply drains into cranial cavity- dangerous as cavity traps pathogens, so can potentially go into cranial cavity
paranasal sinuses DIAGRAM- innervation and function
frontal sinuses, ethmoid air cells/sinuses, sphenoid and maxillary sinuses (next to nose- has honeycombed structure) supplied by trigeminal nerve- lighten skull, act as crumple zone and help project sound
sinus drainage DIAGRAM
meatuses are where drainage from sinuses occur- most of ethmoidal, and frontal and maxillary sinus drain into middle meatus, sphenoidal sinus into sphenoethmoidal recess, nasolacrimal duct into inferior meatus, POSTERIOR ethmoidal sinus into superior meatus
functions of larynx
main function is valve to prevent food going into airway- secondary function to produce sound
anatomy of larynx and vocal cords DIAGRAM
hyoid with epiglottis, connected to thyroid cartilage by thyrohyoid membrane- thyroid cartilage and laryngeal prominence between thyroid and cricoid cartilage is midline cricothyroid membrane- thyroid cartilage rocks back and forth on cricoid cartilage (by cricothyroid joint) to adjust tension on vocal cords- this tension causes VOCAL CORDS to open (to allow air in) or close (prevent food) or partially open (to produce sound)
cricoid and arytenoid cartilage DIAGRAM
arytenoid cartilages sit on top of cricoid cartilages
view of opened/closed airway DIAGRAM
glotti/rima glottidis is opening between two vocal folds
intrinsic muscles of larynx DIAGRAM
unlike muscles connected to hyoid bone for swallowing, these affect VOCAL FOLDS cricothyroid muscle shortens to bring thyroid and cricoid cartilage closer, as thyroid cartilage rocks forward, placing more TENSION on vocal cords in posterior view, lateral cricoid arytenoid and vocalis reduce tension, closing the glottis muscles at back (transverse arytenoid and posterior cricoarytenoid ABDUCT vocal cords, opening glottis
innervation of intrinsic muscles of larynx
vagus nerve divides into superior laryngeal nerve, and recurrent laryngeal nerve lower down recurrent laryngeal nerve longer of left side, as has to wind around ligamentum arteriosus between aortic arch and pulmonary trunk- right one only has to wind around right subclavian artery superior laryngeal divides into internal (does lot more) and external laryngeal nerve (less)
effect of lesions to different parts of innervation+ relation to arteries
damage before vagus nerve branches causes complete paralysis damage to internal laryngeal nerves causes SENSATION LOSS above vocal folds ie cannot have reflexes eg cough if this area stimulated by bad things damage to external causes paralysis of CRICOTHYROID (external only supplies this) damage to recurrent causes paralysis of all intrinsic muscles + sensation loss BELOW vocal folds, EXCEPT cricothyroid vulnerable during thyroid surgery, as superior laryngeal travels with SUPERIOR THYROID ARTERY, recurrent travels with INFERIOR THYROID ARTERY
protective mechanisms for airway to prevent ASPIRATION
GAG reflex sneezing and coughing- sneezing afferent via V2, coughing afferent via X- soft palate RAISED in coughing via, but DEPRESSED in sneezing, both via vagus: both cause ABDUCTION of vocal folds
functions of facial nerve
motor for muscles of facial nerve, digastric and stylohyoid muscles (FACIAL EXPRESSION AND SWALLOWING/MASTICATION, as innervates buccinator as well) sensory- TASTE(anterior 2/3rds of tongue), parasympathetic for lacrimal glands (LACRIMATION), sublingual/submandibular glands (SALIVATION), mucous glands of nasal cavity and hard/soft palates sensation from external acoustic meatus branch going into through INTERNAL ACOUSTIC MEATUS AND STYLOMASTOID FORAMEN, and small branch to peritympinoid fissure
route of intracranial infection through ear DIAGRAM
infection can travel through auditory tube to mastoid antrum and air cells to erode temporal bone= intracranial infection
outer ear and components of auricle DIAGRAM
auricle contains helix and lobule, antihelix, tragus/antitragus and conchae
middle and inner ear DIAGRAM
both part of temporal bone- middle ear goes from tympanic membrane to oval window
middle ear DIAGRAM
ossicles transmit vibrations from tympanic membrane to oval window- malleus, incus and stapes pharyngotympanic/auditory tube- equalises pressure between middle ear and external pressure
features of tympanic membrane that are seen through otoscope DIAGRAM
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landmarks of nasal cavity DIAGRAM
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different bones in nasal cavity DIAGRAM
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