anterior triangle part 2
TRANSCRIPT
Anatomyoftheneck
Anteriortriangle- part2
Dr.MohamedElfiky
ProfessorofanatomyandEmbryology
Submandibularregion
DigastricMuscle
Stylohyoid
Posteriorbellyofdigastric
Anteriorbellyofdigastric
Origin : arises by two bellies 1. Anterior belly : from the digastric fossa on the lower border of the mandible close to the symphysis menti. 2. Posterior belly : from the mastoid notch on the medial side of the mastoid process Insertion : into the intermediate tendon which is attached to the hyoid bone by a fibrous bully. Nerve supply : 1. Anterior belly : by nerve to mylohyoid (from the
mandibular) because it develops from the first branchial arch.
2. 2.Posteriorbelly:fromthefacialnervebecauseitdevelopsfromthesecondbranchialarch.
Actions:1. Depressesthemandible2. 2.Elevatesthehyoidbone Mylohyoid
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1. Mastoid process with
sternomastoid.
2. Parotid gland : between the
mastoid process and the angle of the
mandible.
3. Angle of the mandible.
4. Submandibular salivary gland.
Superficial relations of post. Belly of digastric
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DeepRelationsofthePosteriorBellyofdigastrica. Three big vessels :
1. Internalcarotidartery
2. Externalcarotidartery.
3. Internaljugularvein
b.Threecranialnerves:
1.Vagus :liesbetweentheinternaljugularveinandtheintercarotidartery
(posteriorly).
2.Hypoglossal:betweentheinternaljugularveinandtheintocarotidartery
3.Accessorynerve:betweenthemuscleandtheinternaljugularvein
(C)Alongitsupperborder:
1. Posteriorauricularartery
2. 2.Stylohyoidmuscle
(D)Alongitslowerborder
1.Occipitalartery
2.HypoglossalnerveMohamed el fiky
Stylohyoid
Site: lies along the upper border of the posterior belly of
digastric
Origin : posterior surface of styloid process.
Insertion : body of the hyoid bone at its junction with and the
greater cornu.
Nervesupply:facialnerve
Actions:pullsthehyoidboneupwardsandbackwards
Note:itstendonisperforatedbytheintermediatetendonof
thedigastricmuscle
StylohyoidMuscle
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MylohyoidMuscleThe two mylohyoids form the floor the floor of the mouth (oral diaphragm). Origin : mylohyoid line of the mandible. Insertion: 1.Posterior one-fourth of fibers: into the body of the hyoid bone. 2. Anterior three – fourths of fibers : into the median raphe
which extends 3.from the symphysis menti to the hyoid bone
Nerve supply : mylohyoid nerve. Actions: 1. elevation of floor of the mouth in the first
stage of deglutition 2. depression of the mandible.3. elevation of the hyoid bone
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2- Muscles
3- Glands
4- Vessels1- SkinandFascia
Platysma
AnteriorBellyofDigastric
SubmandibularLymphNodesSuperficialPartofSubmandibularGland
SubmentalandMyelohyoidVessels
1- SuperficialRelationsofmylohyoid
1. anterior belly of digastric
2. superficial part of the submandibular salivary gland
3.mylohyoidnerveandvessels
4.submentalvesselsandlymphnodes.
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1- GlandsSublingualGlandDeepPartofSubmandibularGland
anditsDuct
2- Nerves
ligual Nerveand
SubmandibularGanglionHypoglossalNerve 3- Muscles Hyoglossus
GeniohyoidGenioglossusStyloglossus
2- DeepRelationsof mylohyoidb) Deep relations: 1) Hyoglossus muscle : with the
following structures intervening between it and the mylohyoid: a) Styloglossusmuscleb) Lingualnerveand
submandibularganglion.c) Submandibulargangliond) Deeppartof
submandibularglandanditsduct
e) Hypoglossalnerve:2)Genioglossusmuscle:anteriortothehyoglossus.3)Sublingualsalivarygland:onthelateralsurfaceofthegenioglossus
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Hyoglossus MuscleOrigin : body and greater cornu of the hyoid bone. Insertion : posterior half of the side of the tongue. Nerve supply : hypoglossal nerveActions : depression of the tongue.
(A) Superficial (lateral) relations: a. overlapped by the mylohyoid musclesb. structures intervening between the mylohyoid and hyolossus are as follows from above downwards 1.Styloglossus muscle 2.Lingual nerve 3.Submandibular ganglion : suspended from the lingual nerve by 4.two roots. 5.Deep part of submandibular gland and its duct. 6.Hypoglossal nerve and vena comitans hypoglossi. 7.Suprahyoid branch of the first part of lingual artery.
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4.Glossopharyngealnerve.
1.Genioglossusmuscle.2.Middleconstrictormuscle
ofpharynx.
6.Lingualartery.
5.Stylohyoidligament.
3.Inferiorlongitudinalmuscleofthetongue.
(B) Deep ( medial) relations of hyoglossus:
1- Genioglossus
2- Middle constrictor of pharynx
3- Glossopharyngeal nerve
4- Stylohyoid ligament
5- Lingual artery.
(C) Structures passing deep to
the posterior border of hyoglossus :
from above down are:
1. Glossopharyngeal nerve
2. stylohyoid ligament
3. lingual artery.
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Glosspharyngealnerve
Stylohyoidligament
Lingualartery
StructuresthatappearatthePosteriorBorder
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Geniohyoid Muscle
Origin : inferior genial tubercle
Insertion : anterior surface of the body of the hyoid bone
Nerve supply : C1 through the hypoglossal nerve.
Actions:
u Elevates the hyoid bone
v Depresses the mandible when the hyoid bone is fixed
Geniohyoid Muscle
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GenioglossusMuscle
Shape : fan – shaped ; forms the main bulk of the tongue.
Origin : from the superior genial tubercle of the mandible
Insertion : into the tongue.
Nerve supply : hypoglossal nerve.
Actions:
1. acting alone: pulls the tongue forwards to the
opposite side.
2. withitsfellowoftheopposite:protrudethetongue
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SubmandibularGlandSuperficialpart
Deeppart
Mylohyoidmuscle
Parotid
SubmandibularGland
Size : about the size of walnut
Parts: the gland is divided into 2 parts :
(A) Superficial part : is large and lies superficial to the
mylohyoid muscle
(B) Deep part : is small and lies deep to the mylohyoid
muscle.
The two parts are continuous with each other around the
posterior border of mylohyoid muscle.
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Superficialpart
DeeppartBody of Mandible
Mylohyoidmuscle
Facialartery
Facialvein
The superficial part of the submandibular gland Superficial part has has 3 surfaces a. Inferolateral b. Lateral c. Medial
1) Inferolateral surface : related to : a. Skin b. Platysmac. Cervical branch of the facial nerve d. Deep fasciae. Facial vein.f. Submandibular lymph node 2) Lateral surface : is related to : a. Submandibular fossa below the mylohyoid line.b. Insertion of medial pterygoid c. Facial artery.
3) Medial surface: Anterior part : is related to the mylohyoid muscle from which it is separated bythesubmentalvessels,mylohyoidnerveandvessels.Ø Posteriorpart:isrelatedtothehyoglossus musclefromwhichitisseparatedbythefollowingstructures:1- Stryloglossus muscle.2- Lingualnerveandsubmandibularganglion3- Hypoglossalnerve4- Suprahyoidartery.
Lingualnerve
Lingualartery
Lingualvein
Mylohyoidmuscle
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Hypoglossalnerve
Lingualnerve
DeepPartof
SubmandibularGland
Genioglossus
SublingualGland
DeepPartofTheSubmandibularGlandExtends forwards in the interval between the mylohyoid and the hyoglossusRelations: Laterally : mylohyoid muscle Medially:hyoglossus muscleAbove:lingualnerveandsubmandibularganglionBelow:hypoglossalnerve.
Submandibular duct: • Is about 5cm long • Emerges from the anterior end of the deep part of the gland• Runs forwards on the hyoglossus under cover of the
mylohyoid • It then runs between the sublingual gland and the
genioglossus muscle • where the lingual nerve crosses lateral and then hooks below
it opens in the floor of the mouth , on the summit of the sublingual papilla at the side of the frenulum of the tongue
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NerveSupplyoftheSubmandibularGlandNerve supply: 1. Sensory supply : from the lingual nerve.
2. Sympathetic : from the sympathetic plexus around the facial
artery
3. Parasympathetic (secretomotor): from the chorda
tympani branch of facial along the lingual nerve
Arterial supply: from the facial and lingual arteries
Venous drainage : into the common facial or lingual veins
Lymphatic drainage : into the submandibular lymph nodes
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FlooroftheMouth
MylohyoidMuscleDeepPartof
SubmandibularGland
GenioglossusLigual Nerve
SubmandibularDuct
SublingualSalivaryGland
Site : located in the floor of the mouth between the mucous membrane and the Mylohyoid muscle occupying the sublingual fossa of the mandible. Shape : almond – shaped Size:isthesmallestofthethreemainsalivaryglands,3to4gminweightRelations:Superiorly:mucousmembraneofthefloorofthemouthwhichisraisedbytheglandtoofformthesublingualfold.
Inferiorly:mylohyoidmuscleMedially:genioglossusmuscle,lingualnerveandsubmandibularductLaterally:sublingualfossaofthemandibleDucts: 8-20ductscomeoutoftheglandtoopenintothefloorofthemouthonthesummitofthesublingualfold.Arterialsupply:sublingualandsubmentalarteriesVenousdrainage:lingualandfacialveinsLymphaticdrainage:submentalandsubmandibularlymphnodesNervesupplysupply:sameasthatofthesubmandibulargland
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Hypoglossalnerve
Genioglossus
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TheLingualNerveCourse in the submandibular region :
Ø Runs on the lateral surface of the hyoglossus deep to the
mylohyoid muscle.
Ø Finally it passes between the genioglossus and the
sublingual gland. Here it hooks around the submandibular duct
and divides into branches.
Distribution : u Carries general senation from the anterioir two-thirds of the
tongue and the floor of the mouth.
v The chorda tympani branch of the facial nerve which is
secretomotor (parasympathetic) to the submandibular and
sublingual salivary gland and gustatory to the anterior 2/3 of the
tongue is also distributed through
ChordaTympani
InferiorAlveolarnerve
Lingualnerve
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MedialPterygoidMuscle
Lingualnerve
LateralPterygoidMuscle
StyloglossusMuscle
Lastmolartooth
SuperiorConstrictorofPharynx
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SubmandibularGanglion
SubmandibularGanglionSite : lies on the hyoglossus muscle where it is suspended from
the lingual nerve by two roots.
Roots : 1. Sensory root : from the lingual nerve (passes without relay).
2. Sympathetic root : from the plexus around the facial artery
(passes without relay).
3. Parasympathetic (motor) root:
• Thepreganglionicfibersarisefromthesuperiorsalivary
nucleusintheponsandpasssuccessivelythroughthefacial
nerve,chordatympaniandlingualnervestorelayinthe
ganglion.
• Thepostganglionicsecretomotor fiberssupplythe
submandibularandthesublingualglands.Mohamed el fiky
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