By:By: Prof. Saeed MakaremProf. Saeed Makarem

By the end of this session the students should know:

Salivary Glands Submandibular &

Sublingual

Parasympathetic Ganglion Submandibular

Lymph NodesSubmandibular group

•It consists of a mixture of serous It consists of a mixture of serous and and mucousmucous acini. acini.•It lies beneath the It lies beneath the lower border lower border of the body of the mandible.of the body of the mandible. •It is divided into It is divided into superficial superficial and and deepdeep parts by the parts by the mylohyoid mylohyoid muscle. muscle. •The deep part of the gland lies The deep part of the gland lies beneath the mucous membrane beneath the mucous membrane of the floor of the mouth. of the floor of the mouth. •The The submandibular ductsubmandibular duct emerges from the anterior end of emerges from the anterior end of the deep part of the gland & the deep part of the gland & runs forward beneath the runs forward beneath the mucous membrane of the mouth. mucous membrane of the mouth. •The duct The duct opensopens into the floor of into the floor of the mouth on a small papilla, the mouth on a small papilla, which is situated at the side of which is situated at the side of the the frenulum of the tongueof the tongue.

Submandibular GlandSubmandibular Gland

Anteriorly: anterior belly of digastric. Posteriorly: posterior belly of digastric , stylohyoid & parotid gland. Medially: mylohyoid, hyoglossus, lingual nerve, submandibular ganglion hypoglossal nerve. Laterally: submandibular fossa of the

mandible. NB. Inferolaterally, it is

covered by the investing layer of deep cervical fascia, platysma & skin.

Anteriorly: sublingual gland. Posteriorly: posterior belly of digastric & stylohyoid, parotid gland. Medially: hyoglossus & styloglossus. Laterally: mylohyoid muscle & superficial part of the gland. Superiorly: lingual nerve & submandibular ganglion. It is covered by the mucous It is covered by the mucous

membrane of floor of the membrane of floor of the mouth.mouth.

InferiorlyInferiorly:: hypoglossal nerve.

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The hyoglossushyoglossus is a flat, quadrilateral muscle. Origin:Origin: from the upper border of the body and greater cornu of the

hyoid bone. Insertion:Insertion: to the side of the tongue. Action:Action: depression of tongue. Nerve supply:Nerve supply: hypoglossal nerve.

It emerges from the anterior end of the deep part of the gland. It passes forward along the side of the tongue, beneath the mucous membrane of the floor of

the mouth. It is crossed laterally by the lingual nerve. It then lies between the sublingual gland and the genioglossus muscle. It opens at the summit of a small papilla, situated at the side of the frenulum of the tongue. The duct and the deep part of the gland could be palpated through the mucous membrane of

the floor of the mouth.

•The sublingual gland lies beneath the mucous membrane (sublingual fold) of the floor of the mouth, close to the frenulumfrenulum of the tongue •It has both serous and mucous acini. •The sublingual ducts (8 to 20 in number) open into the mouth on the summit of the sublingual fold.

Nerve Supply

Parasympathetic secretomotor supply is from the facial nerve via the chorda tympani, and the submandibular ganglion.

Postganglionic fibers pass directly to the gland.

Sublingual GlandSublingual Gland

Relations:› Anteriorly : the gland of the opposite side› Posteriorly:› deep part of the submandibular gland› Medially:› genioglossus muscle, ›lingual nerve &› submandibular duct› Laterally:› sublingual fossa of the mandible› Superiorly:› mucous membrane of the floor of the mouth. The gland forms the sublingual fold.› inferiorly:› mylohyoid muscle.

Blood supply: facial and lingual

arteries. Venous

drainage: into the facial

and lingual veins. Lymph

drainage: submandibular &

deep cervical lymph nodes.

.

Small parasympathetic ganglion

Location: on the lateral surface of the

hyoglossus muscle. Suspended from the lingual

nerve by several branches; Preganglionic

parasympathetic fibers reach the ganglion from the superior salivary nucleus of the facial nerve via the chorda tympani & lingual nerves.

The pre-ganglionic fibers synapse within the ganglion, and the post ganglionic fibers pass to the submandibular & sublingual salivary glands.

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Parasympathetic secretomotor supply from the superior superior salivary nucleussalivary nucleus of the seventh cranial nerve.

The nerve fibers pass › to the

submandibular submandibular ganglionganglion via

› the chorda chorda tympani nervetympani nerve and

› the lingual lingual nervenerve.

Postganglionic parasympathetic fibers pass to the gland via the lingual lingual nerve.nerve.

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Postganglionic sympathetic fibers reach the gland as a plexus of nerves around the facial and lingual arteries.

The submandibular lymph nodes are situated on the superficial surface of the submandibular salivary gland.

They can be palpated just below the lower border of the body of the mandible.

They receive lymph from a wide area, including the anterior two thirds of the tongue (except the tip); the floor of the mouth & vestibule; and the gums.

The efferent lymph vessels drain into the deep cervical lymph nodes.

The submental lymph nodes are situated in the submental triangles.

They receive lymph from tip of the tongue, floor of the mouth beneath the tip of the

tongue, incisor teeth and the associated gums, center part of the lower lip, skin over the chin. The efferent lymph vessels drain into the

submandibular and deep cervical lymph nodes.

The deep cervical lymph nodes form a chain along the course of the internal jugular vein, from the skull to the root of the neck. They are embedded in the fascia of the carotid sheath and the tunica adventitia of the internal jugular vein; Most lie on the anterolateral aspect of the internal jugular vein. Two of the nodes are often referred to clinically and are called the jugulodigastric node and the jugulo-omohyoid node.

The jugulodigastric node lies just below the posterior belly of the digastric muscle and is located just below and behind the angle of the mandible. It is chiefly concerned with the lymph drainage of the tonsil and the tongue.

The jugulo-omohyoid node is related to the intermediate tendon of the omohyoid muscle and is associated mainly with the lymph drainage of the tongue.

The sublingual The sublingual salivary gland, salivary gland, opens into the opens into the mouth by mouth by numerous numerous small ducts. small ducts.

Blockage of Blockage of one of these one of these ducts is ducts is believed to be believed to be the cause of the cause of cyst (Ranula)cyst (Ranula) under the under the tongue.tongue.