Ear, Nose and Throat Flashcards
(130 cards)
What does the outer ear consist of?
- Auricle-> cartilage (helix, tragus, concha) + lobule to capture + direct sound
- External auditory canal-> concha to tympanic membrane, outer 1/3 cartilage + produces wax, inner 2/3 bone
What is cauliflower ear?
- Blood accumulates between cartilage and perichondrium
- Disrupts blood supply
- Avascular necrosis
What is the tympanic membrane?
- Boundary between external + middle ear
- Umbo meets lateral process of malleus bone
- Pars flaccida (weak) + pars tensa
- Light reflex-> at 5’oclock (right ear) or 7 oclock (left)
What does the middle ear consist of?
- 1 nerve-> facial (CNVII)
- 2 muscles-> tensor tympani + stapedius (restrict ossicle movement + protect from loud noise)
- 3 bones/ossicles-> malleus + incus + stapes (from tympanic membranes to oval window + pass vibrations to inner ear)
- Mastoid process
- Eustachian tube
What is the mastoid process?
- Area of temporal bone behind ear
- Air cells protect ear + equalise air pressure
What is the role of the Eustachian tube?
- Middle ear has no direct contact with the atmosphere
- Pressure differences between outer + middle ear
- ET-> opens + allow equalisation
What does the inner ear consist of?
- Vestibular-> 3 semi-circular canals, utricle + saccule, messages to CNVIII
- Cochlear-> oval window, scala media + tympani + vestibuli (transmit into signals via organ of Corti)
How do the semicircular canals work?
- Endolymph + sensory hair cells
- Detect direction + flow when move
- Sends messages to CNVIII
What are the functions of the nose?
- Ventilation
- Humidify air
- Smell via olfactory nerve
- Protect airway from pathogens-> mucous + hairs
- Drainage from sinuses + tear ducts
- Middle ear ventilation via Eustachian tube
What is the anatomy of the nose?
- Cartilage, septum + bone
- Cavity-> vestibule to nasopharynx with CNI on superior aspect
- Superior, middle + inferior turbinates-> on lateral walls to increase surface area + improve humidity
What is the arterial blood source of nose?
- Little’s area-> Keisselbach’s plexus, anterior, source of epistaxis
- Woodruff’s plexus-> cause posterior nose bleeds
Who is at risk of posterior nose bleeds?
Older, HTN, atherosclerosis
Where do anterior nose bleeds usually come from?
Little’s area-> Keisselbach’s plexus
Where do posterior nose bleeds come from?
Woodruff’s plexus
What is the anterior triangle of the neck?
- Mandible (superior)
- Midline of neck (medial)
- Sternocleidomastoid (lateral)
What structures are in the anterior triangle of the neck?
- Thyroid + parathyroid
- CNs IX, X and XII
- Carotid artery
- Internal jugular vein
- Salivary glands
What is the posterior triangle of the neck?
- Sternocleidomastoid (anterior)
- Clavicle (inferior)
- Trapezius (posterior)
What structures are in the posterior triangle of the neck?
- Subclavian artery and vein
- External jugular vein
- CN XI
- Brachial plexus
Where are branchial cysts usually located?
Anterior triangle of the neck
Where are cystic hygromas usually located?
Posterior triangle of the neck
What anatomical structures are in the throat?
Hard + soft palate, uvula, palatine tonsils, tongue
Where are salivary tumours usually located?
Parotid gland
What runs through the parotid gland?
CN VII (facial nerve)
What is Stensen’s duct and where can it be found?
- Where saliva secreted from the parotid gland
- Feel as bulge on cheek opposite the second molar