Dr. Mohamed Elfiky

1. Anatomy of the neck
Anterior triangle - part 2
Dr. Mohamed El fiky
Professor of anatomy and Embryology
Submandibular region

2. Digastric Muscle
Stylohyoid
Posterior belly of
digastric
Anterior belly of
digastric
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. Posterior belly : from the facial nerve because it
develops from the second branchial arch.
Actions :
1. Depresses the mandible
2. 2. Elevates the hyoid bone Mylohyoid
Mohamed el fiky

3. 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
Mohamed el fiky

4. Deep Relations of the Posterior Belly of digastric
a. Three big vessels :
1. Internal carotid artery
2. External carotid artery.
3. Internal jugular vein
b. Three cranial nerves :
1. Vagus : lies between the internal jugular vein and the inter carotid artery
(posteriorly).
2. Hypoglossal : between the internal jugular vein and the into carotid artery
3. Accessory nerve : between the muscle and the internal jugular vein
(C) Along its upper border :
1. Posterior auricular artery
2. 2. Stylohyoid muscle
(D) Along its lower border
1. Occipital artery
2. Hypoglossal nerve
Mohamed el fiky

5. 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.
Nerve supply : facial nerve
Actions : pulls the hyoid bone upwards and backwards
Note : its tendon is perforated by the intermediate tendon of
the digastric muscle
Stylohyoid Muscle
Mohamed el fiky

6. Mylohyoid Muscle
The 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
Mohamed el fiky

7. 2- Muscles
3- Glands
4- Vessels1- Skin and Fascia
Platysma
Anterior Belly of Digastric
Submandibular Lymph Nodes
Superficial Part of Submandibular Gland
Submental and Myelohyoid Vessels
1- Superficial Relations of mylohyoid
1. anterior belly of
digastric
2. superficial part of the
submandibular salivary
gland
3. mylohyoid nerve and
vessels
4. submental vessels and
lymph nodes.
Mohamed el fiky

8. 1- Glands
Sublingual GlandDeep Part of Submandibular Gland
and its Duct
2- Nerves
ligual Nerve
and
Submandibular Ganglion
Hypoglossal Nerve 3- Muscles Hyoglossus
Geniohyoid
Genioglossus
Styloglossus
2- Deep Relationsof mylohyoid
b) Deep relations:
1) Hyoglossus muscle : with the
following structures
intervening between it and the
mylohyoid:
a) Styloglossusmuscle
b) Lingual nerve and
submandibular ganglion.
c) Submandibularganglion
d) Deep part of
submandibular gland and
its duct
e) Hypoglossalnerve:
2) Genioglossus muscle : anterior
to the hyoglossus.
3) Sublingual salivary gland : on
the lateral surface of the
genioglossus
Mohamed el fiky

9. Hyoglossus Muscle
Origin : body and greater cornu of the hyoid bone.
Insertion : posterior half of the side of the tongue.
Nerve supply : hypoglossal nerve
Actions : depression of the tongue.
(A) Superficial (lateral) relations:
a. overlapped by the mylohyoid muscles
b. 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.
Mohamed el fiky

10. 4. Glossopharyngeal nerve.
1. Genioglossus muscle.
2. Middle constrictor muscle
of pharynx.
6. Lingual artery.
5. Stylohyoid ligament.
3. Inferior longitudinal muscle of the tongue.
(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.
Mohamed el fiky

11. Glosspharyngeal
nerve
Stylohyoid
ligament
Lingual artery
Structures that appear at the Posterior Border
Mohamed el fiky

12. 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
Mohamed el fiky

13. Genioglossus Muscle
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. with its fellow of the opposite : protrude the tongue
Mohamed el fiky

14. Submandibular Gland
Superficial part
Deep part
Mylohyoid muscle
Parotid
Submandibular Gland
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.
Mohamed el fiky

15. Mohamed el fiky

16. Superficial part
Deep part
Body of Mandible
Mylohyoid muscle
Facial artery
Facial vein
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. Platysma
c. Cervical branch of the facial nerve
d. Deep fascia
e. 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
by the submental vessels , mylohyoid nerve and vessels.
Ø Posterior part : is related to the hyoglossus muscle from which it is separated by the following structures :
1- Stryloglossus muscle.
2- Lingual nerve and submandibular ganglion
3- Hypoglossal nerve
4- Suprahyoid artery.
Lingual nerve
Lingual artery
Lingual vein
Mylohyoid muscle
Mohamed el fiky

17. Hypoglossal nerve
Lingual nerve
Deep Part
of
Submandibular Gland
Genioglossus
Sublingual Gland
Deep Part of The Submandibular Gland
Extends forwards in the interval between the mylohyoid and the hyoglossus
Relations:
Laterally : mylohyoid muscle
Medially : hyoglossus muscle
Above : lingual nerve and submandibular ganglion
Below : hypoglossal nerve.
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
Mohamed el fiky

18. Nerve Supply of the Submandibular Gland
Nerve 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
Mohamed el fiky

19. Floor of the Mouth
Mylohyoid Muscle
Deep Part of
Submandibular Gland
Genioglossus
Ligual Nerve
Submandibular
Duct
Sublingual Salivary Gland
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 : is the smallest of the three main salivary glands ,
3 to 4 gm in weight
Relations :
Superiorly : mucous membrane of the floor of the
mouth which is raised by the gland to of form the
sublingual fold .
Inferiorly : mylohyoid muscle
Medially : genioglossus muscle , lingual nerve and submandibular duct
Laterally : sublingual fossa of the mandible
Ducts : 8-20 ducts come out of the gland to open into the floor of the mouth on the summit of the sublingual fold.
Arterial supply : sublingual and submental arteries
Venous drainage : lingual and facial veins
Lymphatic drainage : submental and submandibular lymph nodes
Nerve supply supply: same as that of the submandibular gland
Mohamed el fiky

20. Hypoglossal nerve
Genioglossus
Mohamed el fiky

21. The Lingual Nerve
Course 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
Chorda Tympani
Inferior Alveolar nerve
Lingual nerve
Mohamed el fiky

22. Medial Pterygoid
Muscle
Lingual nerve
Lateral Pterygoid
Muscle
Styloglossus
Muscle
Last molar tooth
Superior Constrictor of Pharynx
Mohamed el fiky

23. Submandibular Ganglion
Submandibular Ganglion
Site : 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:
• The preganglionic fibers arise from the superior salivary
nucleus in the pons and pass successively through the facial
nerve , chorda tympani and lingual nerves to relay in the
ganglion.
• The postganglionic secretomotor fibers supply the
submandibular and the sublingual glands.
Mohamed el fiky

24. Thank
You