Module 10: Special Senses Flashcards
(234 cards)
1
Q
- Contains vestibulocochlear organ
- Consists of 3 main parts: External, Middle, Internal
- 2 functions: Balance and hearing
A
Ear
2
Q
• Composed of
- Auricle (collects sounds)
- External acoustic meatus (conducts sounds to tympanic membrane)
A
External Ear
3
Q
- Shell like part
- Consists of single elastic cartilage which is continuous with cartilage of external acoustic meatus
- Contains: hair,sweat/sebaceous glands
- Shape varies
- Lobule – no cartilage, can be pierced for earring
A
Auricle
4
Q
• Auditory passage • Extends from concha to tympanic membrane (TM) • S-shaped, 2.5cm long • Composition: o Lateral 1/3: Cartilage o Medial 2/3: Bony • Infants: PURE cartilage
A
EXTERNAL ACOUSTIC MEATUS (EAM)
5
Q
• Lined with skin • Contents: o Hair follicles o Sebaceous glands o Ceruminous glands – produce cerumen
A
EXTERNAL ACOUSTIC MEATUS (EAM): Lateral Part
6
Q
- Lined with thin skin
- Isthmus – constricted part
*This is where most foreign bodies gets lodged or impacted (ex. Ipis)… killed the insect with baby oil, water or hydrogen peroxide,
A
EXTERNAL ACOUSTIC MEATUS (EAM): Medial Part
7
Q
EXTERNAL ACOUSTIC MEATUS (EAM): Arterial supply
A
- Post-auricular branch of External carotid artery (ECA)
- Deep auricular branch of Maxillary artery
- Auricular branch of Superficial temporal artery
8
Q
EXTERNAL ACOUSTIC MEATUS (EAM): VENOUS DRAINAGE
A
- External jugular vein (EJV)
- Maxillary vein
- Pterygoid plexus
9
Q
EXTERNAL ACOUSTIC MEATUS (EAM): NERVE SUPPLY
A
- Auricotemporal nerve (from CN V)
- Tympanic plexus (from CN VII)
- Auricular branch (from CN X)
10
Q
(Clinical Anatomy)
• When doing otoscopic exam, know the anatomy of EAM
A
- Directed anteriorly and medially
* Pull the ear superiorly, posteriorly, and laterally
11
Q
- Thin, semitransparent, oval membrane
- Medial end of EAM
- Separates external from middle ear
- Oblique and slopes inferomedially
- Pearly gray and shiny
A
TYMPANIC MEMBRANE
12
Q
- Concavity toward the EAM with a central depression called umbo, formed by the handle of malleus
- From umbo, bright area emanates called cone of light
- Moves in response to air vibrations that pass to it
- Vibrations are transmitted from TM by auditory ossicles through the middle ear to the internal ear
A
TYMPANIC MEMBRANE
13
Q
TYMPANIC MEMBRANE: Arterial Supply
A
Maxillary artery
o Deep auricular artery
o Posterior auricular artery
o Tympanic branch
14
Q
TYMPANIC MEMBRANE: Venous Drainage
A
• External jugular vein
15
Q
TYMPANIC MEMBRANE: NERVE SUPPLY
A
• Auriculotemporal nerve (from CN V3)
16
Q
Clinical Anatomy: Tympanic Membrane
A
• Perforation of TM
o Deafness
o Etiology: Foreign bodies, Infection, Excessive pressure as in scuba diving
• During PE, pull the auricle superiorly, posteriorly, and laterally
17
Q
• Narrow cavity in petrous part of temporal bone • Contents: o Auditory ossicles o Stapedius o Tensor tympani o Chorda tympani nerve
A
MIDDLE EAR
18
Q
MIDDLE EAR: Connections
A
o Anterior: Nasopharynx
o Posterosuperior: Mastoid antrum
19
Q
Middle Ear
A
When the plane descends, you experience some type of ear pain. That is because of your ear being equalized. If you have difficulty equalizing, the pain will persist for a couple of days hanggang sa maging infection na siya. That is what we refer to as para-trauma of your middle ear.
20
Q
WALLS OF MIDDLE EAR
A
• ROOF or TEGMENTAL
Formed by tegmen tympani
Separates middle ear from dura
• FLOOR or JUGULAR
Formed by bone Separates middle ear from IJV (Internal Jugular Vein)
• LATERAL or MEMBRANOUS
Formed by TM (Tympanic Membrane)
21
Q
WALLS OF MIDDLE EAR: MEDIAL or LABYRINTHINE
A
• Semicircular ducts and cochlea • Separates middle ear from inner ear • 2 small windows: 1. Fenestra vestibule o Closed by base of stapes o Through this window, vibrations of stapes are transmitted to inner ear
- Fenestra cochlea
o Closed by a secondary TM
o Allows perilymph to move in response to impulses
22
Q
WALLS OF MIDDLE EAR: POSTERIOR or MASTOID
A
- Leads to mastoid antrum via an opening, aditus
- Pyramidal eminence
- Contains the stapedius muscle
23
Q
WALLS OF MIDDLE EAR: INFERIOR or CAROTID
A
2 openings which connects:
• With canal occupied by tensor tympani
• With nasopharynx through auditory tube
24
Q
- Otherwise known as your Eustachian / Pharyngotympanic tube
- Funnel-shaped
- Connects nasopharynx to middle ear
- 3.5-4 cm long
- 1/3: Bone; 2/3: Cartilage
- Function: Equalizes pressure in middle ear with atmospheric pressure
A
AUDITORY TUBE
25
What happens when you’re not able to equalize as the plane descends?
Your Eustachian tube will have a dysfunction. It is not able to open up. That is why you are instructed to do a Valsalva maneuver. Or you can pinch your nose and swallow.
26
AUDITORY TUBE: Arterial Supply
* Ascending pharyngeal artery
* Middle meningeal artery
* Artery of pterygoid canal
27
AUDITORY TUBE: VENOUS DRAINAGE and NERVE SUPPLY
VENOUS DRAINAGE: Pterygoid plexus
| NERVE SUPPLY: Tympanic plexus (CN VII and IX
28
* Ear bones
* Form a chain across middle ear
* From Tympanic Membrane to oval window
* Function: Increase the force but decrease amplitude of vibrations transmitted from tympanic membrane
* Consists of: Malleus, Incus, Stapes
AUDITORY OSSICLES
29
Malleus / Hammer (Parts)
Head
o Rounded superior part
o Lies in epitympanic recess
o Articulates with incus
Neck
o Lies vs flaccid part of TM
o Where chorda tympani nerve crosses
Handle
o Embedded in TM
o Where tendon of tensor tympani inserts
30
Incus (Parts)
Body: Articulates with head of malleus
Long Process: Articulates with stapes
Short Process: Connected to tympanic cavity by a ligament
Lenticular Process: Articulates with head of stapes
31
Stapes (Parts)
* Smallest bone
* Base – fits into oval window
* Head – articulates with lenticular process of incus
32
```
- 2 cm long
Origins
-cartilaginous part of auditory tube
- greater wing of sphenoid bone
- petrous part of temp bone
Insertion: Handle of malleus
NS: Mandibular n [CN V3]
Action:
- pulls handle of malleus thus tenses TM
- reduces amplitude of oscillations
- prevents damage to int ear when exposed to loud sounds
```
TENSOR TYMPANI
33
```
Origin: pyramidal eminence
Insertion
: Neck of stapes
NS: Nerve to stapedius [CN VII]
Action
- Reduces oscillatory range
- Prevents excessive movement of stapes
```
STAPEDIUS
34
* Contains the vestibulocochlear organ
* Concerned with reception of sound and maintenance of balance
* In petrous part of temporal bone
* Consists of sacs and ducts of membranous labyrinth
* Membranous system contains endolymph and end organs for hearing and balance (these are specialized neuro-epithelial structures)
INTERNAL EAR
35
* Surrounded by perilymph
| * Suspended within bony labyrinth
Membranous Labyrinth
36
• Composed of:
1. Cochlea
2. Vestibule
3. Semicircular canals
Bony Labyrinth
37
* Shell-like
| * Contains the cochlear duct
Cochlea
38
Cochlea: Parts
o Cupula – apex
o Osseous spiral lamina – shelf of bone
o Basilar membrane – attached to ossicles
o Spiral ganglion
o Organ of corti – concerned with auditory perception
o Scala vestibule – opens into vestibule
o Scala tympani – related to tympanic cavity at fenestra cochlea
39
```
• Oval bony chamber
• About 5 mm
• Contains utricle and saccule, which are parts of balancing apparatus
• Continuous:
o Anteriorly with cochlea
o Posteriorly with semicircular canals
```
Vestibule
40
* Bony canals which open into vestibule
* Set at right angles to each other
* Three: Anterior, Posterior, Lateral
* Forms 2/3 of a circle
* About 1.5 mm diameter except at swelling called ampulla (this ampulla correspond to your organ of Corti which contains your specialized neurons)
Semicircular Canals
41
• Sacs and ducts in cavities of bony labyrinth
• Follows the form of bony labyrinth but smaller
• Contains watery fluid, endolymph
• Consists of 3 parts:
1. Utricle and Saccule
2. 3 Semicircular ducts
3. Cochlear duct
MEMBRANOUS LABYRINTH
42
• Dilatations
• With a specialized area of sensory epithelium, macula
• Macula
o Static organs for signaling position of the head in space
o Macula utriculi – in utricle
o Macula sacculi – in saccule
Utricle and Saccule
43
* Each duct has an extension containing sensory area called Crista ampullaris
* Sensors of movement
* Hairs of cristae are supplied by primary sensory neurons whose cell bodies are in vestibular ganglion
Semicircular Ducts
44
* Spiral
* Blind tube firmly fixed to cochlear canal by spiral ligament
* Roof: Vestibular membrane
* Floor: Basilar membrane
* Spiral organ of Corti
Cochlear Duct
45
• Receptor of auditory stimuli
• Contains hair cells that respond to vibrations induced in the endolymph by sound waves
• It is in this area where the hydronium energy coming from the vibration or wave process called by the stimulation of the fluid inside the inner ear, area where it is converted to the air impulse by hair cells >> the electric impulses are conducted by auditory nerve going to auditory center in
the brain (temporal lobe). The brain is responsible for processing these electric impulses.
Spiral organ of Corti
46
Bony >> Membranous >> Sensory Organ
Cochlea >> Cochlear duct >>Organ of Corti
SC canal >> SC duct >> Crista terminalis
Vestibule Utricle/Saccule >> Macula
47
• Narrow canal
Runs laterally for about 1 cm
Within petrous part of temporal bone
• Closed laterally by a thin, perforated plate of bone that separates it from internal ear
• Through his plate pass CN VII, VIII
• CN VIII – divides near lateral end of IAM into anterior cochlear portion and posterior vestibular portion
INTERNAL ACOUSTIC MEATUS (IAM)
48
Pathway of Sound Conduction
```
Auricle >> External acoustic meatus
>> Tympanic membrane
>> Ossicles [malleus,incus,stapes]
>> Perilymph vibrations
>> Cochlea >> CN VIII >> Brain
```
49
* Formation of spongy bone around stapes and fenestra vestibuli
* May stop movement of base of stapes
* Causes deafness
* Not common among Filipinos
OTOSCLEROSIS
50
* Inflammation of middle ear
* May spread to tegmen tympani
* Causes inflammation of meninges
* Common among Filipinos
OTITIS MEDIA
51
* Inflammation of EAM
| * Movement of tragus causes pain because cartilage in it is continuous with EAM
OTITIS EXTERNA
52
* Forms a route through which infections pass from nasopharynx to middle ear
* Blocked by swelling of its mucous membrane
* Residual air in the tympanic cavity is absorbed into the mucosal blood vessels
* Lowering of pressure in tympanic cavity, retraction of tympanic membrane
* Hearing reduced
* Magkakaroon ng transmutation of fluid from your intravascular space going to your middle ear (high pressure
AUDITORY TUBE
53
* Tympanic muscles have protective action
* Dampen large vibrations of tympanic muscles from loud noises
* Paralysis of stapedius (lesion of CN VII) results in excessive hearing
* Results from uninhibited movement of stapes
HYPERACUSIA
54
* Spherical sinus
* At temporal bone
* Connected to tympanic cavity by aditus
* Separated from middle cranial fossa by tegmen tympani
* Very sensitive to sound
MASTOID ANTRUM AND CELLS
55
* Results from infection of middle ear
| * During surgery, ENT should not injure the CN VII
Mastoiditis
56
* Persistent exposure to loud sounds
* Causes degenerative changes in spiral organ at base of cochlea
* Drill handlers, machine operators, tractor drivers
HIGH TONE DEAFNESS
57
* Injury to ear by an imbalance in pressure between surrounding air and air in middle ear
* In fliers, divers, parachuters
OTIC BAROTRAUMA
58
* Projects from the face
| * Vary in size and shape because of differences in nasal cartilage
EXTERNAL NOSE
59
EXTERNAL NOSE (Parts)
```
o Root – superior angle
o Apex – tip
o Nares – 2 piriform openings
o Alae – lateral boundaries
o Nasal septum – middle structure which separates 2 nares
o Vestibule – with stiff hairs
```
60
EXTERNAL NOSE (Skeletal Part)
* Nasal bones
* Frontal process of maxilla
* Nasal part of frontal bone
61
EXTERNAL NOSE (Cartilaginous Part)
* 2 lateral cartilages
* 2 alar cartilages
* 1 septal cartilage
62
• Divides the chamber of the nose into 2 nasal cavities
• Components:
o Perpendicular plate of ethmoid
Forms superior part of the nasal septum
o Vomer – thin flat bone that forms the posteroinferior part of the nasal septum
o Septal cartilage – articulates with bony septum
NASAL SEPTUM
63
* Open posteriorly into the nasopharynx thru the choanae
| * Mucosa lines the nasal cavities except for vestibule (lined with skin)
NASAL CAVITIES
64
Nasal Mucosa
Olfactory area
o Superior 1/3
o Contains organ of smell
Respiratory area
o Inferior 2/3
o Where air is warmed and moistened before it goes to respiratory tract
65
```
• 3 scroll-shaped elevations
• Superior, middle, inferior
• Divide the nasal cavity into 4 passages:
o Sphenoethmoidal recess
o Superior meatus
o Middle meatus
o Inferior meatus
```
NASAL CONCHA
66
Nasal Passage (1)
Sphenoethmoidal Recess: Sphenoidal sinus
| Superior Meatus: Posterior ethmoidal sinus
67
Nasal Passage (2)
Middle Meatus:
Interior/Middle ethmoidal sinus
Frontal sinus
Maxillary sinus
Inferior Meatus: Nasolacrimal duct
68
Nose (Arterial Supply)
Branches of:
1. Sphenopalatine artery
2. Anterior and posterior ethmoidal artery
3. Greater palatine artery
4. Superior labial artery
5. Lateral nasal branches of facial artery
69
- Anterior
- Where all arteries anastomose
- Where nose bleeding occurs
- Most common site of epistaxis
- Other name: Little’s area
Kiesselbach’s area
70
Nose: VENOUS DRAINAGE
* Sphenopalatine veins
* Facial veins
* Ophthalmic veins
71
NOSE: NERVE SUPPLY
NERVE SUPPLY (Nasal Septum):
- Nasopalatine nerve
- Greater palatine nerve
- Anterior ethmoidal nerve
- Posterior ethmoidal nerve
NERVE SUPPLY (Smell): Olfactory nerve; Olfactory bulb (forebrain)
72
```
• Air-filled extensions of the respiratory part of the nasal cavity into the following cranial bones:
o Frontal
o Ethmoid
o Sphenoid
o Maxillary
```
PARANASAL SINUSES
73
* Between outer and inner tables of frontal bone
* Detectable by 7 years old
* Drains through frontonasal duct into ethmoidal infundibulum which opens into semilunar hiatus of middle meatus
* Nerve supply: Branch of supraorbital nerves (from CN V1)
FRONTAL SINUS
74
• Comprise several ethmoidal cavities – ethmoidal cells
• At ethmoid bone
Parts:
o Anterior – drain into middle meatus
o Middle – form ethmoidal bulla; drain into middle meatus
o Posterior – drain into superior meatus
• Nerve supply: Nasociliary nerve (from CN V1)
ETHMOIDAL SINUS
75
* Unevenly divided
* Body of sphenoid
* Separated by thin plates of bone from optic nerve and chiasma, ICA, pituitary gland
* Opens into sphenoethmoidal recess
* Nerve supply: Posterior ethmoidal nerve
SPHENOIDAL SINUS
76
• Largest
• Pyramidal shaped
• Parts:
o Apex – into zygomatic bone
o Base – inferior part of lateral wall of nasal cavity
o Roof – formed by floor of orbit
o Floor – formed by alveolar part of maxilla
• Drains via maxillary ostium into middle meatus
• Nerve supply: Superior alveolar nerves (from CN V2)
MAXILLARY SINUS
77
• Fibromuscular tube
• Extends from the base of the skull to the lower border of the cricoid cartilage (at which point it becomes the esophagus)
• Portions of the pharynx lie posterior to:
o Nasal cavity >>Nasopharynx
o Oral cavity >> Oropharynx
o Larynx >> Laryngopharynx
• Behind nasal cavities, mouth, and larynx
• Funnel-shaped
• Musculo-membranous wall
PHARYNX
78
* Continuous with nasal cavity, mouth, larynx and tympanic cavity
* UPPER: ciliated columnar epithelium
* LOWER: stratified squamous epithelium
Pharynx: Mucous membrane
79
* ABOVE: thicker, stronger, connected to base of skull
| * BELOW: continuous with submucous coat of esophagus
Pharynx: Fibrous layer
80
The muscular walls of the pharynx are comprised of an outer layer made up of 3 circularly disposed muscles, the __. They are logically named (from superior most to inferior most) the SUPERIOR, MIDDLE and INFERIOR PHARYNGEAL CONSTRICTORS
CONSTRICTORS
81
Consists of:
- superior constrictors
- middle constrictors
- inferior constrictors
Fibers:
- circular fashion
- stylopharyngeus ms.
- salpingopharyngeus ms.
Pharynx: Muscular Layer
82
Origin:
- medial pterygoid plate
- pterygoid hamulus
- pterygomandibular ligament
- mylohyoid line
Insertion:
Upper - pharygeal tubercle; Middle – median fibrous raphe
Nerve supply: pharyngeal plexus
Action: contract and pull post pharyngeal wall forward during swallowing aid soft plate in closing off nasopharynx
Superior Constrictor Muscle
83
Origin: stylohyoid ligament lesser and greater cornua of hyoid
Insertion: median fibrous raphe
Nerve supply: pharyngeal plexus
Action: contracts and propels food bolus down into esophagus
Middle Constrictor Muscle
84
```
Origin: thyroid cartilage; cricoid cartilage
Insertion:
superior fibers – MCM
lower fibers – esophagus
median fibrous raphe
```
Nerve supply: pharyngeal plexus
Action: propel bolus of food into esophagus cricopharyngeus muscle – sphincteric effect
Inferior Constrictor Muscle
85
Origin: styloid process, temporal bone
Insertion: between SCM and MCM
Nerve supply: glossopharyngeal nerve
Action: elevate larynx and pharynx during swallowing
Stylopharyngeus Muscle
86
Origin: lower part, auditory tube
Insertion: blend with palatopharyngeus
Nerve supply: pharyngeal plexus
Action: assists in elevating pharynx
Salpingopharyngeus
87
The__ takes origin, as the name suggests, from the soft palate, and runs down the length of the pharynx, intermingling with fibers of the stylopharyngeus below the inferior border of the superior constrictor
PALATOPHARYNGEUS
88
NASOPHARYNX (Roof, Floor, Anterior Wall)
Roof:
- body of sphenoid
- basilar part of occipital bone
- pharyngeal tonsil
Floor:
- soft palate
- pharyngeal isthmus
Anterior wall: posterior nasal apertures
89
NASOPHARYNX (Posterior and Lateral Wall)
Posterior wall: anterior arch of atlas
Lateral wall:
- auditory tube
- tubal elevation
- salpingo pharyngeal fold
- pharyngeal fold
- tubal tonsil
90
* A vertical fold of mucous membrane that extends inferiorly from the medial end of the pharyngotympanic tube
* It covers the salpingopharyngeus muscle
SALPINGOPHARYNGEAL FOLD
91
OROPHARYNX (Roof and Floor)
Roof: Soft palate; Pharyngeal isthmus
Floor:
- 1/3 tongue and epiglottis
- Lingual tonsil
- Median glossoepiglottic fold
- 2 lateral glossoepiglottic fold
- Vallecula
92
OROPHARYNX (Anterior Wall, Posterior Wall and Lateral Wall)
Anterior Wall: Mouth; Tongue
Posterior Wall: C2, C3
Lateral Wall:
- Palatoglossal and palatopharyngeal arches/folds
- Palatine tonsils
93
- Upper epiglottis and cricoid
- Anterior wall: Inlet of pharynx
- Posterior wall: C3-C6
- Lateral wall: Thyroid cartilage
- Pyriform fossa
LARYNGOPHARYNX
94
Pharynx: Arterial Supply and Venous Drainage
BLOOD SUPPLY
- Ascending pharyngeal artery
- Ascending palatine artery
- Facial artery
- Maxillary artery
- Lingual artery
VENOUS DRAINAGE
- Pharyngeal venous plexus
- Internal Jugular Vein
95
Pharynx: Lymphatic Drainage and Nerve Supply
LYMPHATIC DRAINAGE
Deep cervical LN
Retropharyngeal / Paratracheal LN
NERVE SUPPLY
Pharyngeal plexus CN IX-X Sympathetic nerves
Motor: CN X, XI
Sensory: Maxillary nerve, CN IX, CN X
96
ACTIONS OF THE PHARYNGEAL MUSCLES
* During swallowing, successive contraction of the superior, middle, and inferior constrictor muscles helps to propel the bolus (ball) of food down into the esophagus.
* Contraction of the 3 longitudinal muscles of the pharynx helps to raise the pharynx, effectively aiding it in engulfing the bolus of food.
* In between acts of swallowing, the lowest fibers of the inferior constrictor are thought to act as a sphincter, guarding the entrance to the esophagus and preventing the entry of air into the digestive system
* Kapag wala ‘tong mga muscles na ‘to, puro air ang ma-swallow mo, pwede kang kabagin
97
MOTOR INNERVATION OF THE MUSCLES OF THE PHARYNX AND LARYNX : ACCESSORY NERVE (XI) Exception: The __ receives its motor innervation from the GLOSSOPHARYNGEAL NERVE (IX) (Note that this is the ONLY muscle innervated by this nerve)
STYLOPHARYNGEUS MUSCLE
98
Nerve Supple of the Pharynx
SENSORY INNERVATION OF THE PHARYNX:
GLOSSOPHARYNGEAL NERVE [IX]
PARASYMPATHETIC INNERVATION OF THE PHARYNX : vagus nerve [X]
99
Lymphatic Drainage: Special lymphatic tissue of the pharynx (1)
o The pharynx contains a “ring” of specialized lymphatic tissue designed to prevent the entry of pathogens into the digestive and respiratory tracts
o In the clinics, “ring” is referred as Waldeyer’s Ring of lymphatic tissue
100
Lymphatic Drainage: Special lymphatic tissue of the pharynx (2)
o This specialized lymphatic tissue is known as ”tonsils” and is organized into 3 groups:
- Nasopharyngeal tonsils (adenoids) – located in the nasal pharynx
- Palatine tonsils (tonsils) – located between the palatoglossal and palatopharyngeal folds in the oral pharynx
- Lingual tonsils – located on the posterior surface of the tongue
101
– also called Faucial tonsils; ito ang tinatanggal namin during Tonsillectomy located at the lateral side of your oral cavity
Palatine tonsils
102
* Minsan a child will come to you complaining of nasal obstruction. Nose breather naman siya tapos hindi naman ganun kadami yung sipon. So most probably you will diagnose it as enlargement of adenoids, which is common in children. Kasi active ang adenoids sa pagproduce ng immunoglobulins and antibodies.
* Pathologic na siya kapag sobrang laki na
* Adenoidectomy – shave the area of adenoid fat pad to remove the enlarged part of adenoid tissue. Minsan sinasabay na ang Tonsillectomy kasi malaki na rin ang tonsils
Nasopharyngeal tonsils
103
* Nag-eenlarge usually sa mga heavy smokers, heavy drinkers at fond sa oral sex
* To palpate, use your “dirty finger” at kung matigas magduda na kayo baka may tumor, pero kung soft siya like your tongue, okay lang yun. Enlarged lingual tonsil yun.
Lingual tonsils
104
* 4th tonsils derived from Eustachian tube
| * Clinical significance: pwedeng panggalingan ng nasopharyngeal tumors
Tubal tonsils
105
• Apparatus made up of cartilage, ligaments, muscles, mucous membrane, which guards the entrance to the lower respiratory passages (trachea, bronchi, and lungs) and houses the vocal cords
• 3 important functions: Protection; Respiration; Phonation
• Voice is an “overlaid function”
- Systems used to produce speech developed long before man learned to speak
LARYNX
106
ANATOMIC REGIONS: SUPRAGLOTTIS
- Epiglottis
- AE folds
- Arytenoids
- False Vocal Cords
107
ANATOMIC REGIONS: GLOTTIS
- True Vocal Cords
- Anterior commissure
- Posterior commissure
108
ANATOMIC REGIONS: SUBGLOTTIS
- Lower limit of glottis to lower margin of cricoid
109
(LARYNGEAL MEMBRANES)
* Between arytenoids and epiglottis
* Upper: AE folds
* Lower: Vestibular fold
Quadrangular Membrane
110
(LARYNGEAL MEMBRANES)
* Between thyroid and cricoid and arytenoid
* Upper: Vocal ligament
Conus Elasticus
111
LARYNGEAL MUCOSA
• LE: Stratified squamous epithelium
• Pseudostratified ciliated columnar epithelium
• Transitional areas
- Fragile
- Role in localization of laryngeal pathologies
- Upper and lower parts of epiglottis, between superior surface of vocal fold and ventricle, between inferior face of vocal fold and lower larynx and trachea
112
```
• Vibratory Mass Complex
LE: noncornified, stratified squamous
Lamina propria:
o Superficial layer / Reinke’s space (amorphous)
o Intermediate (elastic)
o Deep (collagen)
```
• Nonvibratory mass complex
- Vocalis muscle
VOCAL FOLD MUCOSA
113
* Accumulation of gelatinous substance in Reinke’s space corresponds to your blisters/paltos
* Because of voice abuse
* Management: oral steroids; last resort is to evacuate the inflammatory fluid
Reinke’s Edema
114
LARYNGEAL MUSCULATURE (Major Types of Movements): Movements Affecting the Tension of the Vocal Cords
• Since the vocal cords are attached to the arytenoid cartilages posteriorly and the thyroid cartilage anteriorly, regulation of vocal cord tension (and therefore pitch of the voice) is accomplished primarily by pivoting the thyroid cartilage forward or backward at the cricothyroid joint
115
LARYNGEAL MUSCULATURE (Major Types of Movements): Movements Which Increase/Decrease the Size of the Opening Between the Vocal Cords (Abduction or Adduction of the Vocal Cords)
• Vocal cords on each side are covered with a mucous membrane, so that when they are abducted, relatively little air can pass either between them or around them
116
Extrinsic and Intrinsic Muscles: Innervated by Recurrent laryngeal nerve
o Thyroarytenoid vocalis
o Posterior cricoarytenoid
o Lateral cricoarytenoid
o Intearytenoid
117
Extrinsic and Intrinsic Muscles: Innervated by Superior laryngeal nerve
o Cricothyroid
118
Muscles of Quadrangular Membrane
* Thyroarytenoid
* Thyroepiglottic
* Aryepiglottic
119
Muscles of Conus Elasticus and Arytenoid
* Posterior cricoarytenoid
* Lateral cricoarytenoid
* Arytenoid
120
Muscles Which Affect the Tension of the Vocal Cords
• Cricothyroid Muscles
- Muscles primarily responsible for regulating the tension of the vocal cords
• Small Vocales Muscles
- Lie parallel and inferior to the vocal cords
- Control fine adjustment of vocal cord tension
121
Muscles Which Open and Close the Rima Glottidis (Abduct and Adduct the Vocal Cords)
Abductor: Posterior cricoarytenoid
o The ONLY abductor of the vocal cords
Adductors (major adductors of the vocal cords):
o Lateral cricoarytenoid
o Thyroarytenoid
o Arytenoideus
122
Muscles Which Close Off the Vestibule of the Larynx (Swallowing)
The muscles which are mainly responsible for closing off the vestibule are the:
o Aryepiglotticus
o Thyroepiglotticus
o Thyroarytenoid
123
LARYNX: Arterial Supply and Lymphatic Drainage
BLOOD SUPPLY
Superior laryngeal artery
Inferior laryngeal artery
LYMPHATIC DRAINAGE
Supraglottic: Anterosuperior group
Glottic: Largely devoid
Subglottic:
Anterior: Prelaryngeal LN
Posterolateral: Paratracheal LN
124
Nerve Supply (Sensory): Superior laryngeal nerve (Internal)
- Supraglottic mucosa
- Thyroepiglottic joint
- Cricoarytenoid joint
125
Nerve Supply (Sensory): Superior laryngeal nerve (External)
- Anterior subglottic mucosa
| - Cricothyroid joint
126
Nerve Supply (Sensory): Recurrent laryngeal nerve
- Subglottic mucosa
127
Nerve Supply (Sensory): Nerve of Galen
- Aortic arch
128
Nerve Supply (Motor): Superior laryngeal nerve
Cricothyroid: Adductor, Tensor
129
Nerve Supply (Motor): Recurrent laryngeal nerve
Thyroarytenoid: Adductor, Tensor
Lateral cricoarytenoid, Interarytenoid, Posterior cricoarytenoid: Adductor
130
Nerve Supply (Motor): Nerve of Galen
Tracheoesophageal mucosa, Tracheal smooth muscle: Autonomic
131
- Thin, transparent vascular tissue that extends from the limbus to the mucocutaneous junction of the eyelid
Conjunctiva
132
Conjunctiva
palpebral conjunctiva - lines the inner aspect of the eyelids
bulbar conjunctiva - covers the sclera
Fornix – junction of the palpebral and bulbar conjunction
133
Conjunctiva: Vascular Supply and Nerve Supply
Vascular supply is through the anterior ciliary artery
| Innervated by the 1st division of CN V (ophthalmic division)
134
* Fine, thin, elastic layer which covers the sclera
* Underneath the conjunctiva
* Contains numerous blood vessels --> provide nourishment for the sclera
Episclera
135
* Thick outer coat of the eye
* Normally white and opaque
* Avascular and fibrous (collagen)
* Continuous with the cornea anteriorly and with the dural sheath of the optic nerve posteriorly
* 0.3 mm thick where the EOM’s insert and about 1 mm thick elsewhere
Sclera
136
* Transparent front “window” of the eye
| * Refracts light
Cornea
137
6 layers of Cornea (1-3)
1. Corneal epithelium -nonkeratinized stratified squamous epithelium, regenerative ability
2. Bowman’s layer – collagen fibers
3. Corneal Stroma – thick layer (90%) of regularly arranged collagen fibers (type 1), keratinocytes
138
6 layers of Cornea (4-6)
4. Dua’s layer- thin, strong layer, discovered in 2013
5. Descemet’s membrane – thin acellular layer that serves as the modified basement membrane of the endothelium, collage type IV
6. Endothelium –monolayer of cuboidal cells, not able to regenerate, responsible for the cornea’s deturgescence
139
* The junction between cornea and sclera
| * May develop whitening as part of old age Arcus senilis
Limbus
140
• The space between the cornea and iris
• Contains a watery fluid called aqueous humor
- Normally acellular
- Cells seen in inflammatory and infectious conditions
Anterior Chamber
141
• Angle formed by the inner cornea and iris roots
• Comprised of several structures that make up the eye’s drainage system:
- trabecular meshwork
- Schlemm’s canal
Anterior Chamber Angle
142
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• middle, vascular layer of the eye
• composed of:
- Iris
- Ciliary body
- Choroid - contributes to the blood supply of the retina
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Uveal Tract
143
• Colored part of the eye that controls the amount of light that enters the eye
- Pupil – hole at the center of the iris
• Composed of Blood vessels, connective tissue, melanocytes and pigment cells
Iris
144
Iris
• Iris stroma contains both dilator and sphincter muscles
- Contraction of the sphincter muscle: pupil constriction
- Contraction of the dilator muscles: pupil dilation
• Blood Supply: Major circle of the iris
• sensory innervation - ciliary nerves
145
• Opening at the center of the iris
• Adjusts the amount of light entering the eye
• Pupillary size is determined by the balance between:
- constriction (parasympathetic activity – CN III)
- dilation due to sympathetic activity
Pupil
146
* Structure of the eye that produces aqueous humor
* Contraction of the ciliary body
Changes the tension of the zonular fibers suspending the lens >> increased thickness of the lens >> allows eye to focus at near objects (accommodation)
Ciliary Body
147
* Vascular, pigmented layer between the sclera(externally) and the retina (internally)
* Provides blood supply to the outer retinal layers
Choroid
148
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• Biconvex structure
• Refracts and focuses light on the retina
• Suspended in place by zonule fibers
• Characteristics: Dimensions
- Anteroposterior: 4.0 to 5.0 mm
- Equatorial diameter: 9.0 to 10mm
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Crystalline Lens
149
* narrow space behind the iris and in front of the zonule fibers
* Space anterior to the crystalline lens
* Filled with aqueous humor
* Normally acellular
Posterior Chamber
150
* Large space behind the lens
* Extends up to the retina
* Approximately 4.5 cc in volume
* Filled with a transparent gel-like material called vitreous humor (devoid of blood vessels, 98-99% water, collagen, glycosaminoglycan hyaluronic acids, proteins)
Vitreous Cavity
151
* Thin, semitransparent, multilayer sheet of neural tissue lining the vitreous cavity
* 10 layers (outermost to innermost)
Retina
152
Retina: Layers
1. Retinal pigment epithelium
2. Photoreceptor
3. Outer limiting membrane
4. Outer nuclear layer
5. Outer plexiform layer
6. Inner nuclear layer
7. Inner plexiform layer
8. Ganglion cell layer
9. Retinal nerve fiber layer
10. Inner limiting membrane
153
Retina: Blood Supply
Blood Supply:
Central retinal artery - Branch of the ophthalmic artery; supplies inner 1/3 of the retina
Choroid - Supplied by the ophthalmic artery; Supplies outer 2/3 of the retina
154
• Area of the retina responsible for fine, central vision
Macula lutea
155
* oval depression in the center of the macula
* Approximately 2 disc diameters away from the optic disc
* Slight inferior to the optic disc
Fovea
156
Optic Nerve
- CN II
- 1.2 M axons
- 50 mm long
- Synapses at the lateral geniculate nucleus
Blood supply:
- Circle of zinn-haller
- Short PCA
- Choroidal circulation
- Pial vasculature
157
Optic Nerve: 4 segments
1. Intra-ocular (CN II head) - 1 mm long, 1.5 mm (horizontal diameter), 1.8 mm (vertical diameter)
- Optic disc (visible by fundoscopy)
2. Intra-orbital - 25 mm in length, 3-4.5 mm in diameter
Mas Malaki na siya kysa sa intra-ocular. So bakit? Kasi myelinated na siya. It is also because may lining na siya.
- Lined by dura, arachnoid, and pia mater
- Fuse at the apex of the orbit with periosteum and annulus of zinn
3. Intra-canalicular - 9 mm in length; Within the optic canal
- Firmly anchored to the bone (optic canal)
- Prone to shearing forces during head traumas because it is firmly attached to the bone
4. Intra-cranial - 10 mm long (3-16 mm); Just before it becomes the optic chiasm
158
* X-shaped structure wherein the medial fibers of both optic nerves decussate or cross to the other side
* Suspended above the sella turcica
Optic Chiasm
159
* Paired structures posterior to the optic chiasm
| * Composed of lateral fibers from the ipsilateral optic nerve and medial fibers from the contralateral optic nerve
Optic Tract
160
* Sensory relay nucleus
| * Located in the thalamus
Lateral Geniculate Body
161
* Paired structures that carry visual information from the LGB to the visual cortex
* Pass thru the parietal and temporal lobes
* Meyer’s loop- inferior fibers that pass through the temporal lobe looping around the inferior horn of the lateral ventricle
Optic radiation
162
* Striate cortex or VI (BA17)
* Occiptal lobe
* Responsible for image processing
Primary Visual Cortex
163
* Bony cavity which contains the eye
* “pear-shaped” with the optic nerve representing its stem
* Medial walls separated by the ethmoidal and spenoidal sinuses
* Volume 30cc
* 7 bones: Frontal, Zygomatic, Maxillary, Ethmoidal, Sphenoidal, Lacrimal, Palatine
Orbit
164
Roof of the Orbit - composed of:
Orbital plate of the frontal bone - Contains the Lacrimal gland fossa
Lesser wing of the sphenoid - Contains the optic canal
165
* Depression located at 4mm from orbital margin
| * attachment of the cartilaginous pulley for the superior oblique muscle
Trochlear Fovea
166
Medial Orbital Wall - composed of :
- Maxillary bone
- Lacrimal bone
- Ethmoidal bone
- Lesser wing of the sphenoid
167
* Contains the naso-lacrimal canal and the lacrimal sac
| * paper thin medial wall : “lamina papyracea”
Medial Orbital Wall
168
Lateral Wall of the Orbit formed by:
- Zygomatic bone
- Greater wing of the sphenoid
* Thickest and strongest
169
Lateral Orbital Tubercle: attachment for:
* Check ligament of lateral rectus muscle
* Suspensory ligament of the eyeball
* Lateral palpebral ligament
* Aponeurosis of the levator ligament
170
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• Roof of the maxillary sinus
• Made up of 3 bones:
- Maxillary bone (blow-out fractures)
- Palatine bone
- Orbital plate of zygomatic bone
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Floor of the Orbit
171
Floor of the Orbit
- Contains the infraorbital groove >> Infraorbital foramen
| - Inferior Oblique Muscle
172
* Arises from the orbital floor
| * only extraocular muscle that does not originate from the orbital apex
Inferior Oblique Muscle
173
* Entry portal for all nerves and vessels to the orbit
* Site of the Annulus of Zinn
* Annulus of Zinn – ring of fibrous tissue comprised of the origins of the 4 rectii muscles, superior oblique muscle, levator palpebrae
* Divides the superior orbital fissue
Orbital Apex
174
(orbital apex)
| Superior Orbital Fissure (SOF) : Lateral
• Foramen in the skull between the greater and lesser wings of the sphenoid bone
• Lateral (outside the Annulus of Zinn)
- lacrimal and frontal branch of CN V
- Trochlear nerve
175
(orbital apex)
| Superior Orbital Fissure (SOF) : Medial
Medial (within the Annulus of Zinn)
- Superior and inferior divisions of CN III
- Nasociliary branch of CN V
- Abducens nerve (CN VI)
- Superior ophthalmic vein
176
(orbital apex)
| Optic Canal and Inferior Orbital Fissure
Optic Canal
- Optic nerve
- Ophthalmic artery
Inferior orbital fissure
- Maxillary and pterygoid parts of CN V
- Inferior ophthalmic vein
177
Extraocular Muscles: 4 recti muscles
4 recti muscles
- Superior rectus
- Inferior rectus
- Medial rectus
- Lateral rectus
178
Extraocular Muscles: 2 obliques
2 obliques
- Superior oblique – passes thru trochlea (cartilage attached to frontal bone)
- Inferior oblique
179
Ocular Motility
Abduction – away from the nose
Adduction – towards the nose
Elevation/supraduction – upward
Depression/infraduction - downward
180
Intorsion vs Extorsion
Intorsion/incyclotorsion – rotation of the upper pole of the vertical meridian of the eye towards the nose
Extorsion/excyclotorsion – rotation of the upper pole of the vertical meridian of the away from the nose
181
Medial vs lateral rectus
Medial rectus: adducts
| Lateral rectus: abducts
182
Superior vs Inferior Rectus
Superior rectus: elevates, adducts, intorts
| Inferior rectus: depresses, adducts, extorts
183
Superior oblique vs Inferior oblique
Superior oblique: intorts, abducts, depresses
| Inferior oblique: extorts, abducts, elevates
184
Origin:
All originate from the Annulus of Zinn, except
Inferior Oblique – has its origin from the maxillary bone
Blood Supply: Muscular branches of the ophthalmic artery
Nerve Supply:
CN III: innervates superior, medial, inferior rectus muscles and the inferior oblique
CN IV: innervates the superior oblique
CN VI: innervates the lateral rectus
Extra-ocular Muscles
185
1st major branch of the intracranial ICA
Ophthalmic artery
186
Branches of the Ophthalmic artery (1)
* Central Retinal Artery – enters the optic nerve 8-15 mm behind the globe; supplies the inner retina
* Lacrimal Artery - supplies the lacrimal gland and the upper eyelids
* Muscular branches of the extraocular muscles
187
Branches of the Ophthalmic artery (2)
• Medial palpebral Arteries –supplies
the eyelid
• Posterior Ciliary Arteries
Long Posterior Ciliary Arteries – anterior segment of the eye
Short Posterior Ciliary Arteries – optic nerve, posterior segment of the eye
188
* Outer structures that protect the eyeball from injury and excessive light
* Lubricates the eye surface (Meibomian glands within the tarsus)
Eyelids
189
Eyelids
• Lids come together at the medial and lateral canthi
• Normal eyelid position:
- Upper lid normally covers about 2 mm of the superior limbus
- Lower lid is usually at the level of the inferior limbus
190
* Zone between the upper and lower eyelids
* In adults: 27 mm long and 8 - 11 mm wide
* Entrance to conjunctival sac
Palpebral fissure
191
* is larger and more mobile
* Can be raised 15 mm by levator
* Completely cover cornea when eyes close
Upper eyelid
192
* Thinnest in the body
* Eyelid fold (eyelid crease) – due to insertion of levator aponeurosis near the upper border of the tarsus (may not be present in Asians)
Skin
193
- Punctum
- Eyelashes arise from the anterior portion of the lid margin
- Orifices of the meibomian gland are located along the posterior portion of the lid margin
Lid Margin
194
Gland of Zeis vs Gland of Moll
Gland of Zeis - unilobar sebaceous glands produce an oily substance; Hordeolum
Gland of Moll - ciliary glands, are modified apocrine sweat glands; Stye
195
• Arranged in a concentric band around the interpalpebral fissure
• Orbital - Inserts into the medial canthal tendon, orbital rim and corrugator supercili muscle; Sphincter like action, voluntarily controlled
• Palpebral - May be voluntary or involuntary (for normal
and reflex blinking)
Orbicularis oculi muscle
196
* Extension of the periosteum of the roof and floor of the orbit
* Attaches to the anterior surface of the levator muscle
* Provides a barrier to spread of blood or inflammation
Orbital Septum
197
• Originates from a tendon that blends with the superior rectus and superior oblique muscles at the apex of the orbit
• Divides to form:
- Levator aponeurosis - Produces the eyelid fold
- Superior Tarsal (Mueller’s) Muscle - Elevates the eyelids ; Innervated by superior division of CN III
Levator Muscle
198
* Consist of dense connective tissue not cartilage
| * Attached to the orbital margin by the medial and lateral palpebral ligaments
Tarsus
199
Meibomian glands - Modified holocrine glands -->
oily layer of the tear film
- Chalazion
Tarsus
200
* Narrow, highly vascularized, crescent-shaped fold of conjunctival tissue
* Rich in goblet cells
* Analogous to the nictating membrane in lower animals
Plica Semilunaris
201
* Small, fleshy, ovoid structure
| * Contains sebaceous glands and fine colorless hair
Caruncle
202
- Located in the frontal bone
- Divided into 2 parts by the levator aponeurosis
- Palpebral part – inner to the LA
- Orbital part – outer to the LA
- Blood supply: Lacrimal Artery
Lacrimal Gland
203
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Consists of:
• Lacrimal punctum
• Upper and lower canaliculi
• Nasolacrimal sac
*Flow of tears – due to pump of nasolacrimal sac by orbicularis oculi
• Nasolacrimal duct
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Lacrimal Excretory System
204
* Opens into inferior nasal meatus
| * Valve of Hasne
Nasolacrimal duct
205
* Latin: Lingua
* Greek: Glossa
* Tongue-like anatomical structure
* Essentially a mass of muscles that is mostly covered by mucous membrane
* Can assume a variety of shapes and positions
Tongue
206
Tongue: Anatomic Location
• Partly in the oral cavity and partly in the oropharynx
• Location:
o Below the palate
o Above the floor of mouth
o In front of pharynx
• Attached to the floor of the mouth, hyoid bone and mandible
207
(PARTS OF THE TONGUE)
* Tip of the tongue
* Anterior end of the body
* Rests against the incisor teeth
* Mobile
Apex
208
(PARTS OF THE TONGUE)
* Anterior portion
* Approximately 2/3 of the tongue
* Between the root and the apex
* Mobile
Body
209
(PARTS OF THE TONGUE)
* Posterior portion (posterior third)
* Between the mandible, hyoid, and the nearly vertical posterior surface of the tongue
* The boundary between the body and the root of the tongue is marked by an inverted V-shaped groove called terminal sulcus
Root
210
* Referred as the top of the tongue
* More extensive
* Superior and posterior surface
* Characterized by a V-shaped groove (terminal sulcus of the tongue)
DORSUM OF THE TONGUE
211
* Referred to as the underside of the dorsum of the tongue
* Covered with thin, transparent mucous membrane
* Has no papillae and is smooth
INFERIOR SURFACE (UNDERSIDE) OF THE TONGUE
212
Connected to the floor of the mouth by a midline fold called the __ of the tongue which allows the anterior part of the tongue to move freely
frenulum
213
A __ on each side of the base of the frenulum is present that includes the opening of the submandibular duct from the submandibular gland
sublingual caruncle (papilla)
214
* Congenital oral anomaly called Ankyloglossia or tongue-tie is characterized by an overly large frenulum of the tongue which interferes with tongue movements and may affect speech
* In unusual cases, a frenectomy (cutting the frenulum) in infants may be necessary to free the tongue for normal movements and speech
Frenectomy
215
* Large and flat-topped
* Lie anterior to the terminal sulcus
* Arranged in a V-shaped row
* Surrounded by deep circular trenches, the walls of which are studded with taste buds
* They contain taste receptors in the taste bud
Vallate Papillae
216
* Small lateral folds of lingual mucosa
* Poorly developed in humans
* Contain taste receptors in the taste bud
Foliate Papillae
217
* Long and numerous
* Scaly, conical projections that are pinkish gray
* Arranged in V-shaped rows parallel to terminal sulcus, except at the apex where they tend to be arranged transversely
* Arranged transversely at the apex
* Contain afferent nerve endings that is sensitive to touch
Filiform Papillae
218
* Mushroom-shaped
* Pink or red spots
* Scattered among filiform papillae
* Numerous at apex and margins of the tongue
* Contain taste receptors in the taste buds
Fungiform Papillae
219
* Genioglossus, hyoglossus, styloglossus, palatoglossus
* Alter the position of the tongue
* They mainly move the tongue but they can alter its shape as well
* Originate outside the tongue and attach to it
EXTRINSIC MUSCLES OF TONGUE
220
• Fan-shaped muscles
• Proximal attachment: short tendon from superior part of
mental spine of mandible
• Distal attachment: entire dorsum of tongue; the inferiormost and posteriormost fibers attach to body of the hyoid
• Actions:
o Bilateral activity depresses tongue, especially central
part, creating a longitudinal furrow
o Posterior part pulls tongue anteriorly for protrusion
o Most anterior part retracts apex of protruded tongue
o Unilateral contraction deviate (“wags”) tongue to
contralateral side
Genioglossus
221
When the genioglossus muscle is paralyzed, the tongue
has a tendency to fall posteriorly, obstructing the airway
and presenting the __
risk of suffocation
222
• Thin, quadrilateral muscle
• Proximal attachment: body and greater horn of hyoid
• Distal attachment: inferior aspects of lateral part of tongue
• Actions:
o Depresses tongue, especially pulling its sides inferiorly
o Helps shorten (retrude) tongue
Hyoglossus
223
• Small, short triangular muscle
• Proximal attachment: anterior border of distal styloid process; stylohyoid ligament
• Distal attachment: sides of tongue posteriorly, interdigitating with the hyoglossus
• Actions:
o Retrudes tongue and curls (elevates) its sides,
working with genioglossus to form a central trough during
swallowing
Styloglossus
224
• Narrow, crescent-shaped muscle
• Proximal attachment: palatine aponeurosis of soft palate
• Distal attachment: blends with intrinsic transverse muscles
• Actions:
o Elevates posterior tongue or depresses soft palate
o Acts to constrict the isthmus of fauces
Palatoglossus
225
• Superior longitudinal, inferior longitudinal, transverse
and vertical muscles are confined to the tongue
• Alter the shape of the tongue
• They have their attachments entirely within the tongue and
are not attached to bone
INTRINSIC MUSCLES OF TONGUE
226
o Act together to make the tongue short and thick and to
| retract the protruded tongue
Superior and Inferior longitudinal muscles
227
o Act simultaneously to make the tongue long and narrow,
which may push the tongue against the incisor teeth or
protrude the tongue from the open mouth
Transverse and vertical muscles
228
• Thin layer deep to mucous membrane of dorsum
• Proximal attachment: submucosal fibrous layer and median fibrous septum
• Distal attachment: margins of tongue and mucous membrane
• Actions:
o Curls tongue longitudinally upward, elevating apex and
sides of tongue
o Shortens / Retrudes tongue
Superior Longitudinal
229
• Narrow band close to inferior surface
• Proximal attachment: root of tongue and body of hyoid bone
• Distal attachment: apex of tongue
• Actions:
o Curls tongue longitudinally downward, depressing apex
o Shortens / Retrudes tongue
Inferior Longitudinal
230
• Deep to superior longitudinal muscles
• Proximal attachment: median fibrous septum
• Distal attachment: fibrous tissue at lateral lingual margins
• Actions:
o Narrows and elongates (protrudes) the tongue
Transverse
231
* Fibers intersect transverse muscle
* Proximal attachment: submucosal fibrous layer of dorsum of tongue
* Distal attachment: inferior surface of borders of tongue
* Actions: flattens and broadens the tongue
Vertical
232
Lymph from the tongue takes 4 routes:
o Lymph from root of tongue drains bilaterally into the
superior deep cervical LN
o Lymph from the medial part of the body drains bilaterally
and directly to the inferior deep cervical LN
o Lymph from the right and left lateral parts of the body
drains to the submandibular LN on the ipsilateral side
o The apex and frenulum drains to the submental LN, the
median portion draining bilaterally
233
Tongue: Motor Innervation
• All muscles of the tongue, except the palatoglossus, receive motor innervation from CN XII (Hypoglossal nerve)
• Palatoglossus is a palatine muscle supplied by the
Pharyngeal plexus
234
* Taste bud is composed of taste cells (life span of 10 days)
* From the tip of each taste cell are taste hairs or microvilli protruding outward into the taste pore approaching the cavity of the mouth
* Taste hairs provide the receptor surface for taste
* Application of a taste substance results to the taste hairs becoming depolarized
Taste Receptors
