1.3 Salivary Glands PDF

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Summary

AnatomySALIVARY GLANDS❑ Parotid gland is like a three sided pyramid➢Superior surface➢Superficial surface➢Anteromedial surface# Medial surface is subdivided into anterior and posterior surfaces.➢Posteromedial surfaceSuperior Surface Related to external acustic meatus (indicated with black circle) and...

Description

Anatomy

SALIVARY GLANDS ❑ Parotid gland is like a three sided pyramid ➢ ➢ ➢ ➢

Superior surface Superficial surface Anteromedial surface# Medial surface is subdivided into anterior and posterior surfaces. Posteromedial surface

Superior Surface •

Related to external acustic meatus (indicated with black circle) and zygomatic arch (indicated with black box ).

•

Auriculotemporal nerve (indicated with black arrow) is closely related to superior surface.

#Mandibular n. leaves the cranial cavity from oval foramen and gives a branch called auricotemporal n. . It extends laterally, curves superiorly adjacent to temperomandibular joint. It is close related to parotid gland. #Auricotemporal n. carries nerve fibers to innervate parotid gland but this fibers are not its own fibers, they are actually fibers of glossopharyngeal n. .

Anatomy

1.3 Salivary Glands

Superficial Surface(or lateral surface) •

Covered by skin& superficial fascia.

•

Related to lymph nodes, great auricular nerve(, posterior border of platysma.

#Superficial surface is covered by fibers of platysma muscle. Platysma muscle overlaps parotid gland # The cutaneous nerves of cervical plexus emerge from midpoint of posterior margin of sternocleidomastoid muscle

(yellow circle). Great auricular n. İs one of them and some fibers of it overlaps parotid gland.

Anteromedial Surface • • •

Grooved by the posterior margin of ramus of mandible Covers the posterior part of the masseter Facial nerve emerges from this surface

#Medial surface of parotid gland is subdivided into anterior and posterior surfaces. (anteromedial and posteromedial) #Transvese section in the picture below is from the level indicated by black line.

Masseter m. indicated by black arrow. Ramus of mandible indicated by blue arrow. The red line indicates anteromedial surface of parotid gland. #Posterior part of ramus of mandible grooves anteromedial surface of parotid. #For the picture below: You can see isolated mandible, masseteric muscle. Care please;

#In the picture you can see isolated mandible masseteric muscle and parotid gland. Care please; as you can see posterior part of ramus of mandible grooves anteromedial surface of parotid gland(red circle). Anteromedial surface of parotid g. covers masseteric muscle.

Anatomy

1.3 Salivary Glands

#Picture shows course of facial nerve within the parotid gland and the terminal branches of facial n. #There is a important nerve that leaves crainal cavity from stylomastoid foramen : Facial Nerve. It pierces parotid gland. Within the parotid gland facial n diverges into superior and inferior divisions then this divisions diverge inyo 5 terminal branches. They leave parotid gland from anteromedial surface and innervate facial expression muscles. #During a parotid gland surgery, surgeon may damage the facial nerve and this causes facial paralysis.

Posteromedial Surface Related to ; • mastoid process • Scm muscle • Posterior belly of digastric muscle • Styloid process & ascociated muscles • E xternal carotid artery grooves this surface

• Internal carotid a. and internal juguler vein are seperated from the gland by the styloid process and its muscles. #In the picture SCM, platysma, digastric m removed and parotid gland is faded. You can see styloid process and highlighted associated muscles( superior to inferior : styloglossus m , stylohyoid m, stylopharyngeus m. ) that related to posteromedial surface of parotid. These there muscle are medial to posteromedial surface of parotid gland. #Stylohyoid m. : from styloid proc. to hyoid bone. #Styloglossus m. : from styloid proc. to tongue. #Stylopharyngeus m. : from styloid proc. to internal surface of a muscular tube called pharynx

Anatomy

1.3 Salivary Glands

#Posteromedial surface is indicated with red line. You can also see internal carotid a., internal jugular vein, vagus n. ; they are separated from parotid anterimedial surface of parotid gland with a grup of muscle.

#In the picture you can see higlighted internal carotid artery. It is entering the cranial cavity from carotid canal to supply brain. It ascends along lateral wall of pharynx. Lateral to internal carotid a there is parotid gland but btw internal carotid a and parotid there is a grup of muscle. These muscles are: Stylohyoid m , styloglossus m. , stylopharyngeus m.(you can see these three at the 3d model picture before) and posterior belly of digastric muscle.

Structures Transversing The Parotid Gland ✓ ✓ ✓

External carotid artery Retromandibular vein Facial nerve

External Carotid Artery •

Enters the gland from posteromedial surface

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Gives the the branches maxillary artery and superficial temporal artery within the gland

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Posterior auricular artery may also originate from the external carotid artery within the gland #Common Carotid Artery bifurcates into 2 branches at the level of the superior margin of the thyroid tartilage. External carotid a pierces the parotid. In this picture parotid is removed. In the parotid gland it gives 3 branches( 1 : superficial temporal a, 2: maxillary a, 3: posterior auricular a.) #Faded parotid gland and highlighted external carotid a. . As you see these 3 branches of external carotid artery arises within the parotid gland.

Anatomy

1.3 Salivary Glands

Retromandibular Vein •

Formed by the union of maxillary and superficial temporal veins #formed inside the parotid gland

#superficial temporal vein carries deoxygenated blood from temporal region. Maxillary vein carries deoxygenated blood from cheek region. •

Leaves the gland through the posterior aspect of apex

•

Located superficial to the external carotid artery

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Joins the posterior auricular vein to form external juguler vein #a division from retromandibular vein unites with posterior auricular vein and form External Jugular Vein. #You can see superficial temporal vein entering parotid gland.

#Here is maxillary vein and faded mandible. It extends posteriorly medial to ramus of mandible. And then enters parotid gland

#Maxillary vein and superficial temporal vein enters parotid end unite to form Retromandibular Vein within the gland. Retromandibular vein is posterior to ramus of mandible

Facial Nerve • Enters the gland from the superior part of the posteromedial surface • Divides into two main divisions and these branches pass forward and down behind the mandibular ramus

•

Terminal branches leave the gland by anteromedial surface

#yellow line shows facial nerve in parotid gland. Entering from posteromedial surface leaving from anteromedial surface. Black line is the boundaries of parotid gland. #Inside the parotid gland it diverges into two main branches and these two main branches diverges into 5 terminal branches. Terminal branches leave the gland from anteromedial surface. #facial n leaves cranial cavity from stylomastoid foramen. #3d model picture in the right shows the course of facial n and its branches inside the parotid gland

Anatomy

1.3 Salivary Glands

Terminal branches of facial nerve; 1.

Temporal

2.

Zygomatic

3.

Buccal

4. Marginal mandibular 5.

Cervical

#here you can see the branches of facial nerve. They innervate facial expression muscles. ( ı dont know if they are important for us know but at least look at these pictures for an idea about them).

Vessels of Parotid Gland

#Branches from external carotid a. Supplies parotid gland and deoxygenated blood of parotid gland drains into external jugular vein.

Anatomy

1.3 Salivary Glands

Lymphatics of Parotid Gland •

To superficial and deep cervical lymph nodes

#lymphatic fluid from parotid gland drains into parotid lymph nodes, superficial cervical lymph nodes and deep cervical lymph nodes.

Innervation of Parotid Gland •

Tympanic branch of the glossopharyngeal nerve to otic ganglion

•

From the otic ganglion auriculotemporal nerve carries the secretory fibers to the gland

#You know in the body there are sensory nerve fibers that carry sensory information, motor fibers that innervates skeletal muscles. There is also another type of nerve fiber in body : The Parasympathetic Fibers. They innervate glands to secreting. # there is a cranial nerve ( 9th) that leaves the crainal cavity from jugular foramen called glossopharyngeal nerve. It carries parasympathetic fibers. These parasympathetic fibers first; go to a ganglion( ganglions are nodular structures they include neuron cell bodies) inferior to oval foramen called Otic Ganglion, then they terminate on the neurons in this ganglion ( synapse). After these fibers from otic ganglion join the auricotemporal nerve ( the nearest nerve). Auriculotemporal nerve carries this nerve fibers to parotid gland, they are not nerves of its own auriculotemporal nerve is just carrier. #these parasympathetic fibers increase salivary secretion from gland.

Anatomy

1.3 Salivary Glands

#Pictures show inflammated parotid gland. # Picture in the right is shows the opening of parotid gland. Parotid duct opens to oral cavity at the level of the 2nd molar tooth of maxilla. Parotid duct pearses the cheek to enter the oral cavity. Normally this opening is not visible but because of the inflammation it is visible at the mucosal surface of cheek. #Visible and prominent parotid duct opening is a sign of parotid gland inflammation.

SUBMANDIBULAR GLANDS •

Hook shaped

•

Superficial part

•

Deep part

#It is one of the major salivary glands.

#They are paired. #It is hook shaped and has superficial and deep parts.

Anatomy

1.3 Salivary Glands

Superficial Part of Submandibular Gland •

Outside the oral cavity

•

In the digastric triangle

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Surfaces; Inferior surface Medial surface Lateral surface

#Submandibular gland curves around posterior margin of mylohyoid muscle. In the picture we can see the superficial part of the gland. Deep part is superior to myhlohyoid muscle. This gland covers the posterior margin of mhylohyoid muscle. #The highlighted area in the picture is show the submandibular triangle(digastric triangle). The superficial part is located in there. # Deep part overlies mylohyoid m. Extends anteriorly medial to mandible.

Surfaces of Submandibular Gland •

Inferior surface; covered by skin, platysma, deep fascia Crossed by facial vein &cervical branch of facial nerve.

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Lateral surface; in relation with submandibular fossa Facial artery grooves this surface.

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Medial surface;mylohyoid, styloglossus, posterior belly of digastric m. glossopharyngeal n, hypoglossal n, lingual n, a.v.n mylohyoideus, deep lingual vein.

#In the picture below mandible is removed. You can see the mhylohyoid muscle and and two parts of the submandibular gland. #You can clearly see inferior surface in the upper picture. The vein shown in the picture that crosses inferior surface is facial v. #Lateral surface faces the submandibular fossa(indicated with red circle) Facial artery grooves lateral surface, you can see its course at upper picture(in black circle) #Medial surface: Mylohyoid muscle faces this surface.

Anatomy

1.3 Salivary Glands

#Medial surface of superficial part of submandibular gland: As you see mhylo hyoid muscle has a slope ( indicated with circle) . mylohyoid muscle faces this surface # Posterior belly of digastric muscle and styloglossus muscles are alos medial to medial surface of superficial part of submandibular gland

#Medial surface is close related to 1*hypoglossal n. ( begins from hypoglossal canal descends in neck curving anteriorly and giving terminal branches before entering oral cavity) 2* glossopharyngeal n. (leaves cranial cavity from jugular foramen descends in neck then it gives branches toward to pharynx and oral cavity) #Higlighted 3rd molar and faded mandible. Relation of submandibular gland lingual n. and 3rd molar. #Lingual n is a branch of mandibular n. lingual n descends medial to ramus of mandible then curves anteriorly to reach oral cavity, it carries sensory info from tongue. This nerve is medial to medial surface of sublmandibular gland. It also crosses the duct of submandibular gland (so important). Along it is course it also close related to 3rd molar tooth, when operating this tooth dentist may damage the ligual n. causes sense loss of tongue.

#Mylohyoid muscle is cut and retructed. You can see inferior surface of submandibular gland and important structures related with it.

Anatomy

1.3 Salivary Glands

Deep Part of Submandibular Gland •

Extends forward to posterior end of sublingual gland

•

Lies between mylohoid and hyoglossus muscles

# Superficial part underlies, deep part overlies the mylohyoid muscle.

# Deep parts anterior end is posterior to another salivary gland named sublingual gland we will learn in next slides.

#Deep part of submandibular gland is btw mylohoid(1) and hyoglossus(2)muscle.

Submandibular Duct (Wharton) • Begins from numerous tributaries in superficial part of gland • Emerges from the medial surface of superficial part behind posterior border of mylohyoid muscle, transverses deep part #then it pearses the deep part and leaves the deep part extends anteriorly along the flor of the oral cavity • Passes between genioglossus m and sublingual gland •

Opens in the floor of mouth on the summit of sublingual papilla ( #posterior the inferior incisior teeth)(at the side of frenulum of tongue)

#Opening of this duct elevates the mucosa this elevated mucosa called sublingual papilla.

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Lingual nerve loops under the duct !!!#Wharton duct crossed by the lingual n. So it may be damaged during the operations of wharton duct and sublingual gland. IMPORTANT

Anatomy

1.3 Salivary Glands

Vessels & Lymphatics of Submandibular Gland ➢

Arteries; Facial artery, lingual artery

➢ ➢

Veins; same with the arteries

Lymph nodes; Submandibular, deep cervical lymph nodes

#Picture :Facial artery and vein supplies the submandibular gland.

Innervation of Submandibular Gland •

Sensory; lingual nerve

•

Parasymp; Chorda tympani (#increase saliva secretion)

By chorda tympani parasymp fibers reach lingual nerve synapse in submandibular gang and reach gland #Chorda tympani is a branch of facial n. Parasymp fibers go to gland with lingual nerve. Lingual nerve carries them. •

Symph; sympathetic trunck (#decrease saliva secration)

Symph fibers synapse in sup cervical ganglion, course around arteries (external carotid artery , facial artery) and reach gland # Sympathetic fibers accompany arteries to reach the target organs. !!!

SUBLINGUAL GLANDS •

Above; mucosa of oral floor, raised as a sublingual fold

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Below; mylohyoid muscle

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In front; Ant end of its fellow

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Behind; deep part of submandibular gland

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Lateral; mandible

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Medial; genioglossus muscle

#She used this pictures over and over again, i think we must care about them. # Anterior part en of suplingual glan is attached to opposite suplingual gland #Care please; forming floor of the oral cavity is whic muscle? -- Mylohyoid muscle As you see in the picture sublingual gland sits on the mylohyoid muscle

Anatomy

1.3 Salivary Glands

Extretory Duct of Sublingual Gland •

8-20 in number #this ducts directly opens to the mucosa of the oral cavity

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Smaller sublingual ducts open seperately on the summit of sublingual fold, a few sometimes into submandibular duct

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From anterior part small rami sometimes form major sublingual duct, opening with or near the orifice of the submandibular duct

#These ducts elevates overlying mucosa and formes a fold ( red circle) #Supbmandibular duct is adjacent to this ducts.

Vessels & lymphatics of Sublingual Glands •

Arteries; Sublingual a (lingual artery), submental a (facial artery)

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Veins; Same with aa.

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Lymphatics; Submandibular nodes, deep cervical nodes

#Begining from facial artery a branch called submental branch this artery also pierces the mylohyoid muscle to reach sublingual gland and supplies it #highlighted arteries : upper one is submental other one is lingual a.

Innervation of Sublingual Gland •

Sensory; Lingual nerve

•

Parasymp; Chorda tympani

Presyn. Parasym fibers carried by chorda tympany, pass to lingual nerve ,synapse in submandibular gang and reach gland •

Symp; Sympathetic trunk

Sympathetic fibers synapse in sup cervical gang and around blood vessels (external carotid artery and facial artery) reach the gland #Innervation is same with the submandibular gland.

Anatomy

1.3 Salivary Glands

PHARYNX #Pharynx is a muscular tube. Located posterior to oral, nasal and laryngeal cavities. #Red circle is the base of cranium formed by basilar part of occipital bone (purple) and body of sphenoid bone(black) #pharynx begins from base of cranium at the lvl of 7th vertebra it is continious with esophagus. #pharynx attaches to medial plate of pterygoid process, auditory tube, petrous part of temporal bone and basilar part of the occipital bone

#On the base of the cranium attachment site for the pharynx is medial plate of pterygoid process. (red arrow). Pharynx begins from medial plate of pterygoid process. # Pharynx attaches to auditory tube (white arrow) it attaches to petrous part of temporal bone ( yellow arrow) and finally it attaches to basilar part of the occipital bone (black arrow)

Boundries-Above •

Posterior margin of medial pterygoid plate

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Cartilaginous part of pharyngotympanic tube

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Petrous part of temporal bone

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Pharyngeal tubercle of occipital bone

Below •

Level of C7

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Esophagus

Anatomy

1.3 Salivary Glands

Anterior Wall #Posterior wall of pharynx removed. We can see anterior wall and openings of pharynx. Choanae to nasal cavity, Isthmus faucium to oral cavity and Laryngeal aditus to laryngeal cavity.

Behind-Posterior Wall •

Buccopharyngeal fascia

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Pharyngobasilar fascia

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Between them; Pharyngeal constrictor muscles

#Constrictor muscles contributes to posterior and lateral walls of pharynx. #Also the covering fascias contributes this walls.

Lateral Walls ❑

Constrictor Muscles; (red boxes) ✓

Superior constrictor muscle

✓

Middle constrictor muscle

✓ ❑