ANATOMY & PHYSIOLOGY OF THE SENSES ANATOMY & PHYSIOLOGY 2013-2014.
ENT Anatomy and Physiology
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Transcript of ENT Anatomy and Physiology
ENT Anatomy and PhysiologyENT Anatomy and Physiology
Dr. ZAID AL-DAHWIConsultant ENT
Head of ENT department
KING SAUD MEDICAL CITY
ENT Undergraduate Lecture
Ear Anatomy Ear Anatomy External EarExternal Ear
• Auricle (Pinna)– Collects sound– Sound
localization
Ear Anatomy Ear Anatomy External EarExternal Ear
• External audiotary meatus– Approximately 24mm in
length, “S” shaped– Lateral/Outer 1/3
• in cartilages • wax (cerumen) • hair
– Medial 2/3• bone• wax free
– Skin migration
Increases sound pressure at the tympanic membrane by as much as 5-6 dB (due to acoustic resonance)
Ear Wax (Cerumen)Ear Wax (Cerumen)
1.Keeps skin soft
2. Keeps bugs out
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Mastoid ProcessMastoid Process
• Bony ridge behind the auricle
• Provides support to the external ear and posterior wall of the middle ear cavity
Middle Ear Anatomy Middle Ear Anatomy Boundaries of Middle Boundaries of Middle
EarEar• Middle ear is Air containing space
in temporal bone.
Middle Ear Anatomy Middle Ear Anatomy OssiclesOssicles
• Three ossicles • Mallus, • incus • stapes
• Ossicles are smallest bones in the body
• Act as a lever system• transfer sound from air to
inner ear fluids
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Stapedius MuscleStapedius Muscle
• Connects the stapes to the middle ear wall• Contracts in response to loud sounds; known
as the Acoustic Reflex
Middle Ear Anatomy Middle Ear Anatomy Tympanic membraneTympanic membrane
• Thin membrane• Forms boundary between outer and middle ear• Vibrates in response to sound• Changes acoustical energy into mechanical
energy
Middle Ear Anatomy Middle Ear Anatomy Eustachian tube Eustachian tube
• Equalises pressure between middle ear and atmosphere
Middle Ear Anatomy Middle Ear Anatomy medial wallmedial wall
Oval window Footplate of the
stapes
Round window
Promontory
Middle Ear Anatomy Middle Ear Anatomy The posterior wallThe posterior wall
Mastoid wall
Tympanic aditus
Pyramidal
eminenceChorda tympani
nerve
Ear Anatomy Ear Anatomy Inner EarInner Ear
• Cochlea
• Semicircular canal – Angular acceleration
• Vestibule – Linear acceleration
• Sound transmission through middle ear• Oval Window –
– located at the footplate of the stapes; when the footplate vibrates, the cochlear fluid is set into motion
• Round Window – – functions as the pressure relief port for the fluid set into motion
initially by the movement of the stapes in the oval window
• Cochlea : organ of corti– Snail-shaped organ with a series of fluid-filled tunnels;
converts mechanical energy into electrical energy
Inner Ear Inner Ear CochleaCochlea
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Organ of CortiOrgan of Corti
• The end organ of hearing; contains stereocilia and hair cells.
Hair Cells Frequency-
specificHigh pitch sounds
(base of cochlea)Low pitch sounds
(apex of cochlea)
Inner Ear Inner Ear Vestibular FunctionVestibular Function
• Macula in saccule and utricle – linear acceleration
• Crista in semi-circular canal – angular acceleration
RhinologyRhinology
• Anatomy
• Physiology
Rhinology Rhinology AnatomyAnatomy
• External
Rhinology Rhinology AnatomyAnatomy
• LATERAL WALL OF NASAL CAVITY
It has 3 curved long projections called nasal conchae:
1) Superior turbinate.
2) Middle turbinate.
3) Inferior turbinate.
* The space below each of these conchae is called nasal meatus.
Rhinology Rhinology Nasal septumNasal septum
• Above:– perpendicular plate of
the ethmoid.• Below and in front:
– septal cartilage.• Below and behind:
– vomer.
– Little’s area– Epistaxis
Rhinology Rhinology Roof Roof
• narrow
Formed by :
1.cribriform plate of the ethmoid bone
2.nasal and frontal bones, and posteriorly sphenoid Bone.
Rhinology Rhinology Paranasal SinusesParanasal Sinuses
– Frontal
– Maxillary
– Ethmoid
– Sphenoid
Laryngology Laryngology (Mouth - Pharynx-Larynx-)(Mouth - Pharynx-Larynx-)
Laryngology Laryngology ORAL CAVITYORAL CAVITY
• 1. Lips. • 2. Buccal or cheek
mucosa. • 3. Gums (gingivae). • 4. Hard palate. • 5. Oral tongue. Only
anterior two-thirds
Laryngology Laryngology PHARYNXPHARYNX
• 1. NasophcHynx– extends from the base of skull to
the soft palate
• 2. Oropharynx– extends from the base of skull to
the soft palate includes (Base of tongue, Lingual and Palatinc tonsils, Valleculae)
• 3. Hypopharynx or Laryngopharynx
– extends from hyoid bone to lower border of cricoid cartilage
– continuous with oesophagus.
– opposite the 3rd, 4th, 5th, 6th cervical vertebrae.
– pyriform sinus, post-cricoid region and the posterior pharyngeal wall.
• Structure of Pharyngeal Wall– 1. Mucous
membrane– 2. Pharyngeal
aponeurosis (pharyngobasilar fascia)
– 3. Muscular coat– 4. Buccopharyngeal
fascia
Laryngology Laryngology PHARYNXPHARYNX
• Waldeyer's Ring– Masses of Scattered
lymphoid tissue in the pharynx
• l. Nasopharyngeal tonsil or the adenoids
• 2. Palatine tonsils or simply the tonsils
• 3. Lingual tonsil
• 4. Tubal tonsils (in fossa of Rosenmuller)
• 5. Lateral pharyngeal bands
• 6. Nodules (in posterior pharyngeal wall).
Laryngology Laryngology PHARYNXPHARYNX
palatine (faucial) tonsilspalatine (faucial) tonsils
• Blood Supply of tonsils– l. Tonsillar branch of fac
ial artery. – 2. Ascending pharyngeal
artery from external carotid.
– 3. Ascending palatine, a branch of facial artery.
– 4. Dorsal linguae, branches of lingual artery.
– 5. Descending palatine branch of maxillary artery.
palatine (faucial) tonsilspalatine (faucial) tonsils
• Relations of tonsil
palatine (faucial) tonsilspalatine (faucial) tonsils
• Crypts of tonsil
Laryngology Laryngology LARYNX AnatomyLARYNX Anatomy
Laryngology Laryngology Neck AnatomyNeck Anatomy
Laryngeal CartilagesLaryngeal Cartilages
• Paired
– Arytenoid cartilage– Corniculate
cartilage– Cuneiform
cartilage
• Unpaired:
– Thyroid cartilage– Cricoid cartilage– Epiglottis
Thyroid CartilageThyroid Cartilage
• Angulation more acute in males
• Its function – Shield larynx from injury and – Provide an attachment to vocal cords
Cricoid CartilageCricoid Cartilage
• Signet ring shaped• Stronger than thyroid
cartilage.
• Support to arytenoid
• Only cartilagenous part forms continuous 360 degree ring
EpiglottisEpiglottis
• Thin leaf shaped fibro-cartilage, situated in midline
• Upper free projects up behind base of tongue
• Epiglottic cartilage contains many pits filled with mucous glands
ArytenoidsArytenoids• Paired cartilages, pyramidal
in shape
• Base articulated with cricoid cartilage
• Anterior angle elongated into vocal process which receives insertion of vocal ligament
GlottisGlottis• Consists of
– true vocal cords, – anterior commissure and – posterior commissure
• Anterior 2/3 is membranous
• Posterior 1/3 of cords are called posterior commissure
Intrinsic musclesIntrinsic muscles
Cricothyroid MuscleCricothyroid Muscle
Adductors of the Vocal FoldsAdductors of the Vocal Folds
Abductor of LarynxAbductor of Larynx
Nerve Supply: Derived from the Nerve Supply: Derived from the VagusVagus
• Superior Laryngeal Nerve – Internal -It provides
sensation of the glottis and supraglottis,
– External -It supplies motor function to the cricothyroid muscle which tenses the vocal cords
• Recurrent Laryngeal Nerve – sensation to the subglottic – motor function to the
intrinsic muscles of the larynx.
• Recurrent Recurrent Laryngeal NerveLaryngeal Nerve
– It branches from the vagus in mediastinum and turns back up into the neck.
– On the right, it travels inferior to the subclavian and loops up
– on the left it travel inferior to the aorta and loops up.
THE ENDTHE END
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