Download Ear,Nose,Oral,Pharynx,Larynx

2010
Anatomy 2
TA Session: Ear,Nose,Oral,Pharynx,Larynx
TA: Le Trung
Email: [email protected]
Notes & Questions:
www.LeTrung.com/Med
none
5/31/2010
Anatomy 2: HEAD Block 1
EAR:
Skin-covered elastic cartilage
Collects sound and directs it to
external auditory meatus
Deep depression: concha
Lobule: earlobe

Tensor tympani is inserted into the handle of malleus

Stapedius is inserted into the neck of stapes

Both act simultaneously to damp down the intensity of high-pitched sound waves(& vibration) &
thus protect the delicate structures of internal ear
Cochlea Function:
• Hearing
• Membranous cochlear duct
• Spiral canal begins at the vestibule & makes 2.5 turns around a bony core, the modiolus
(cone shaped core of spongy bone about which the spiral canal of the cochlea turns)
• Basal (first) turn of cochlea produces Promontory
TYMPANIC MEMBRANE
Structure and functions
Id Umbo, Cone of light, Handle of
malleus, Chorda tympani nerve, Pars
flaccida & tensa
Nerve supply – Outer surface:
Auriculotemporal & Arnold’s nerves ;
Inner surface: CN9
AUDITORY OSSICLES (Bones of Middle Ear)
Promontory
Rounded projection overlying basal turn of cochlea ; grooved by the tympanic plexus
Oval window (Fenestra vestibuli)
into which footplate of stapes fits ; leads into the vestibule of internal ear
Round window (Fenestra cochleae) : opens into the scala tympani of the cochlea, & is closed by the
secondary tympanic membrane
Prominence of Facial canal : runs backwards just above fenestra vestibuli, then descends behind the
posterior wall to end at the stylomastoid foramen
AUDITORY (EUSTACHIAN OR PHARYNGOTYMPANIC) TUBE
Function
To equalize pressure in the middle ear with the atmospheric pressure, allowing free movement of
tympanic membrane. By allowing air to enter & leave the tympanic cavity, it balances the pressure on
both sides of the membrane.
Blockage of Auditory tube
Auditory .Tube forms route for infection to spread from nasopharynx to tympanic cavity
The residual air in the tympanic cavity is absorbed into the mucosal blood vessels, resulting in decreased
pressure in the cavity, retraction of tympanic membrane & interference with its free movement; finally,
hearing is affected.
Audio Tube forms route for infection to spread from nasopharynx to tympanic cavity
- the residual air in the tympanic cavity is absorbed into the mucosal blood vessels, resulting in
decreased pressure in the cavity, retraction of tympanic membrane & interference with its free
movement; finally, hearing is affected.
Semicircular ducts
Within corresponding semicircular canals
Ampulla at one end
Ampullary crest(or Crista) – end organ within each ampulla
Respond to pressure changes in the endolymph caused by movements of the head
Innervated by vestibular division of CN VIII
Function
Detect rotational (tilting) movements of head
Maculae are end organs that give information about the position of the head ; they are static
balance receptors
Spiral Organ of Corti
• End organ for Hearing
• Innervated by Cochlear division of CN8
• Present within Cochlear duct (Scala media)
{between Scala vestibuli above & Scala tympani below}
• Rests on Basilar membrane
• Contains Hair cells, the tips of which are embedded in
Tectorial membrane above
Internal auditory (acoustic) meatus
1 cm long tiny canal in petrous ridge of temporal bone
Location
Opening in postero-medial aspect of ridge in posterior cranial fossa
Transmits
CN VII , CN VIII ,Labyrinthine vessels
Otitis externa
Inflammation / infection of external ear
Also called swimmer's ear
Usually bacterial in origin
Pseudomonas aeruginosa
Staphylococcus aureus
Itchiness, a sensation of having the ear blocked, and pain
Ear is painful, erythematous, and may be discharging pus
Treatment:Topical antibiotics (eardrops)
Otitis media
Inflammation of middle ear
Also known as glue ear
Age - In children b/w 6 months to 2 years
Symptoms
Pulling or rubbing the ears because of ear pain
Fever, fussiness, or irritability
Fluid leaking from ear
Changes in appetite or sleeping patterns
Trouble hearing
Cause: Bacterial infection
Otoscopy: Ear drum - dull with loss of cone of light
NOSE & PARANASAL AIR SINUSES
Epistaxis:
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–
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Nosebleed
Common because of rich vascular supply to nose
Occurs in Little's area or Kiesselbach's area
• Anterior 1/3rd of nasal septum
Can be related to hypertension (in old people)
Treatment- Identify source of bleeding, direct pressure, packing nose or cautery
ORAL CAVITY
Hyoglossus
Depresses tongue
Aids in retraction
Styloglossus
Mingles with fibers of hyoglossus
Creates central trough or furrow with
genioglossus during swallowing
Retracts tongue and curls side
Palatoglossus
Largely a soft palate muscle
Elevates posterior tongue
Lymphatic drainage takes one of four routes
Tip (apex) to submental nodes
Anterior medial two thirds to inferior deep
cervical nodes
Anterior lateral two thirds to submandibular
nodes
Posterior one third to superior deep cervical
nodes
Muscles of soft palate
Four paired muscles
Levator veli palatini elevates soft
palate during swallowing, opens
auditory tube
Tensor veli palatini tenses soft palate
during swallowing
Palatoglossus elevates posterior
tongue
Palatopharyngeus tenses soft palate
and pulls pharynx superiorly and
anteriorly during swallowing
Unpaired musculus uvulae shortens
uvula
HardPalatet Forms roof of mouth and floor of nasal
cavities
Two parts
Hard palate anteriorly
Covered with periosteum and oral mucosa
(inferiorly) and respiratory mucosa superiorly
Five foramina
Incisive fossa- behind central incisors transmits
nasopalatine nerves via incisive canals
Greater palatine forami86na (paired)- medial to
third molar transmits greater palatine vessels and
nerves
Lesser palatine foramina (paired)- posterior to
greater palatine foramina transmits lesser palatine
nerves and vessels
Tonsillar fossae
Contain palatine tonsils
Masses of lymphoid tissue between arches
Anatomical features related to soft palate
Arches
Join soft palate to tongue and pharynx
Palatoglossal arch
Mucosal fold
Contains palatoglossus muscle
Palatopharyngeal arch
Mucosal fold
Contains palatopharyngeus muscle
Form anterior and posterior boundaries of
tonsillar fossa on either side
Fauces
Bounded by
Soft palate superiorly
Root of tongue inferiorly
Palatoglossal and palatopharyngeal arches laterally
Muscles of soft palate
Four paired muscles
Levator veli palatini elevates soft palate during swallowing, opens auditory tube
Tensor veli palatini tenses soft palate during swallowing
Palatoglossus elevates posterior tongue
Palatopharyngeus tenses soft palate and pulls pharynx superiorly and anteriorly during swallowing
Unpaired musculus uvulae shortens uvula
Arterial supply
Branches of descending palatine artery on each side
Greater palatine artery
Lesser palatine artery
Ascending palatine artery from facial artery
Venous drainage via pterygoid venous plexus
Lymphatic drainage: deep cervical nodes
Innervation
Sensory from pterygopalatine ganglion
Greater palatine nerve to hard palate
Nasopalatine nerve to anterior hard palate
Lesser palatine nerve to soft palate
Motor
Tensor veli palatini innervated by medial pterygoid nerve from otic ganglion
All other muscles by cranial root of spinal accessory nerve (CN XI) via pharyngeal plexus
Sublingual glands
Smallest and deepest of glands
Lie in floor of mouth within sublingual
folds, between mandible and
genioglossus muscle
Numerous ducts open along
sublingual folds
Arterial supply
Sublingual artery from lingual artery
Submental artery from facial artery
Innervation same as that for
submandibular gland
Submandibular gland
Lies superior and inferior to posterior half of mandible
Divided into superficial and deep parts by mylohyoid muscle
Duct
Opens at sublingual papilla, one on either side of lingual frenulum
Lingual nerve loops under duct
Arterial supply: submental artery
Innervation
Secretomotor parasympathetic fibers
Presynaptic fibers from facial nerve via chorda tympani to submandibular ganglion
Postsynaptic fibers from cells in submandibular ganglion
Vasoconstrictive sympathetic fibers from superior cervical ganglion
Pharynx
Fibromuscular tube ~ 12cm.
Three parts : Nasopharynx, Oropharynx, Laryngopharynx or hypopharynx
Relation- Antariorly- nasal and oral cavities
 Posteriorly- superior six cervical vertebrae and prevertebral muscles and fascia
 Inferiorly- Continuous with both esophagus and larynx
Retropharyngeal space- potential space between pharynx and prevertebral fascia
C6 is the lowest parynx&larynx…. >
Cricoid Cartilage.
Nasopharynx
Posterior to nose and above soft palate
Lined with ciliated epithelia
Boundaries :
Anteriorly: continuous with nasal cavities via choanae
Roof and posterior wall: body of sphenoid and base of occipital bone
Laterally: superior constrictor muscle
Contains openings of auditory (Eustachian) tubes (from middle ear)
Salpingopharyngeal fold
Extends inferiorly from medial end of auditory tube
Covers salpingopharyngeus muscle- opens tube during swallowing
Torus tubarius = ridge over opening
Pharyngeal recess = fossa of Rosenmuller
Slit-like projection
Posterior to torus
Contains abundant lymphoid tissue
Aggregates in certain areas = Tonsil
Lymphoid tissue in mucus membrane of roof and posterior wall = Adenoids
Lymphoid tissue near opening of auditory tube = Tubal tonsil
Oropharynx
From soft palate to superior ends of epiglottis
Boundaries
Anteriorly- oropharyngeal opening, posterior 1/3rd
tongue, epiglottis
Laterally- palatoglossal & palatopharyngeal arches
Superiorly- soft palate
Posteriorly- superior & middle constrictor muscles
Contains palatine tonsils
Found in cleft between palatoglossal & palatopharyngeal arches
Lies on tonsillar bed = superior constrictor muscle & pharyngobasilar fascia
Exposed surface of tonsil has slit like orifices called tonsillar crypts
Blood supply
Tonsillar artery- branch of facial
Twigs from ascending palatine, lingual, descending palatine & ascending pharyngeal arteries
Tonsillar vein drains into facial & lingual vein
Can be a source of profuse hemorrhage after tonsillectomy
Lymphatic drainage: Jugulodigastric lymph node »»» deep cervical lymph nodes
Nerve supply: IX
Tonsillitis:
Bacterial infection of tonsils causing inflammation.
PTA (Peritonsillar abscess) or Quincy
Abscess around the tonsil
Pain can be referred to ear due to common nerve supply.
(tympanic branch to middle ear)
Laryngopharynx
From superior border of epiglottis to inferior border of cricoid cartilage
Stratified squamous epithelium
Boundaries
Inferiorly- continuous with esophagus
Superiorly- continuous with oropharynx
Anteriorly- larynx
Posteriorly- middle and inferior constrictor muscles deep: Bodies of C4–C6 vertebrae
Laterally: middle and inferior constrictor muscles
Piriform recesses
Small depressions on either side of laryngeal inlet
Bounded medially by thyroid cartilage & thyrohyoid membrane
Common place where food/fish bone can be trapped
Give sensation of food stuck in throat
Muscles of Pharynx
Wall of pharynx is unique
Composed of outer circular and inner longitudinal layers of muscles
External circular layer
Consists of three constrictor muscles: pharyngeal constrictors
Inner longitudinal layer
Consists of three paired muscles
Swallowing
A. The bolus of food is squeezed to the
back of the oral cavity by pushing the
tongue against the palate. (Voluntary)
B. The nasopharynx is sealed off and the
larynx is elevated, enlarging the pharynx
to receive food.
C. The pharyngeal sphincters contract
sequentially, squeezing food into the
esophagus. (Involuntary)
D. The bolus of food moves down the
esophagus by peristaltic contractions.
(Involuntary)
Piriform fossa
Common site for fish bones to lodge.
Also a site where pharyngeal tumors can grow undetected for a period of time
Adenoids
Aggregations of lymphoid tissue in nasopharynx
Enlarged in children, causing obstruction of nasopharynx & forcing the child to breathe through mouth
Pharyngitis
~sore throat
Usually by viral infection
In children, common cause of bacterial pharyngitis- β-hemolytic streptococcus
If infection is severe, auditory tubes can become blocked, predisposing to otitis media
S/S- Pain on swallowing & pain referred to ear, throat may be reddened & cervical lymph nodes may be
enlarged
Tonsillectomy
Surgical removal of palatine & lingual tonsils
Advised if patient has experienced recurrent attacks of tonsillitis, particularly if they resulted in airway
obstruction and hearing difficulties
Major and common surgical procedure performed in children in US
Recovery usually within 2 weeks, although for adults this may take longer and can have a higher
complication rate
Larynx
Organ of phonation
Sphincter guarding lower respiratory tract
~8 cm long
Connects oropharynx with trachea
Lies anterior to prevertebral muscles, fascia & bodies of C3–C6 vertebrae
Function:
Opens and closes airway during:
Swallowing, Coughing and sneezing
Regulates passage of air during:
Phonation (speech), Normal
variations in inspiration and
expiration
Vocal Ligament
Extends from the deep surface of the
thyroid cartilage to vocal process of
arytenoid.
Is the thickened free upper boarder of
the conus elasticus
Vocal folds
Paired, project into laryngeal cavity on either side
Consist of
Vocal ligament—medial free edge of lateral cricothyroid ligament (conus elasticus)
Vocalis muscle—medial fibers of thyroid arytenoids muscle
Overlying mucosa
Source of sound
Produce audible vibrations when free edges of folds closely approximate each other
Are sphincter of larynx when folds are tightly approximated
Rima glottidis
Space between vocal folds
Varies in size with activity
During normal breathing: narrow wedge
During forced respiration: wide apart
During phonation: slit-like
Vestibular folds (false vocal cords) mostly for protective function.
Folds of mucous membrane over vestibular ligaments superior to vocal folds
Extend between thyroid and arytenoids cartilages
Protective in function
Actions of selected intrinsic muscles
Posterior cricoarytenoid muscles
Abduct vocal folds by rotating arytenoid cartilages laterally
Lateral cricoarytenoid muscles
Adduct vocal folds by rotating arytenoid cartilages medially
Cricothyroid muscles
Lengthen and tense vocal cords by tilting thyroid cartilage forward on cricoid cartilage
Vocalis muscles
Part of thyroarytenoid muscles lying within vocal folds
Adjust length, thickness, and tension of vocal ligaments
Extrinsic muscles
Are muscles attached to hyoid bone and thus move thyroid
Infrahyoid muscles: lower larynx and hyoid bone
Sternohyoid , Omohyoid ,Sternothyroid , Thyrohyoid
Suprahyoid muscles: Fix hyoid or elevate hyoid bone and larynx
Stylohyoid , Digastric ,Mylohyoid
Stylopharyngeus—elevates hyoid bone and larynx
Innervation of larynx
Sensory
Above vocal folds
Internal laryngeal nerve (branch of superior laryngeal)
Below vocal folds
Inferior laryngeal nerve (branch of recurrent laryngeal nerve)
Motor
Recurrent laryngeal nerve to all intrinsic muscles except cricothyroid
Cricothyroid- External laryngeal nerve
Severance of recurrent laryngeal nerve
Closely associated with inferior thyroid artery and needs to be avoided during neck surgery
If unilateral damage
Hoarseness may result because one vocal fold cannot approximate the other
If bilateral damage
Loss of voice will result because vocal folds cannot approximate each other (be adducted)
Also have a hard time breathing. > Stoidon.
Superior laryngeal artery
Supplies internal larynx
Accompanies by superior laryngeal nerve
Inferior laryngeal artery
Supplies inferior internal larynx
Accompanied by recurrent laryngeal nerve
Laryngoscopy
Procedure used to examine interior of larynx
Larynx may be examined visually by
Indirect laryngoscopy using a laryngeal mirror
Direct laryngoscopy using a tubular endoscopic instrument, a laryngoscope
Cancer of Larynx is very common> weak voice or monotone speech, hoarness voice.
A choking victim can’t speak or breathe!