03 salivary glands, the nose and the associated structures

8/8/2019 03 Salivary Glands, The Nose and the Associated Structures

1/89

SALIVARY GLANDS


2/89

There are three major paired salivary glands:Parotid gland

Submandibular gland

Sublingual gland

There are also minor salivary glands located

within the mucosa of the oral cavity.


3/89

PAROTID GLAND

Largest of the salivary glands

Lies antero-inferior to the external acoustic

meatus

Parotid duct extends antero-inferiorly, pierces

the buccinator muscle and enters the oral

cavityOpens with a small orifice opposite to the 2nd

maxillary molar tooth


4/89


5/89


6/89

Structures within the parotid gland are,

Facial nerve

External carotid artery

Retromandibular vein Parotid duct

Parotid lymph nodes (drain into both the

superficial and deep cervical lymph nodes)


7/89


8/89


9/89

Innervation of the parotid gland

Parasympathetic innervation of the parotid gland isthrough the glossopharyngeal nerve (CN IX)

Course of parasympathetic innervation

GVE fibers of CN IX ----- tympanic nerve (br of CN IX) ---- lesserpetrosal nerve --- otic ganglion --- auriculotemporal nerve (br ofmandibular) ---- paroid gland

Sympathetic innervation is through the externalcarotid plexus (around the external carotid artery-arise from the superior cervical ganglion)


10/89


11/89


12/89

Parasympathetic stimulation of the parotid glandproduces a thin watery saliva


13/89

SUBMANDIBULAR GLAND

Lies medial to to the body of the mandible

Its duct runs medially to open at the side of

lingual frenulum (at the lingual caruncule)


14/89


15/89

Innervation of the submandibular gland

Parasympathetic innervation of the submandibulargland is through the facial nerve (CN VII)

Course of parasympathetic innervation

GVE fibers of CN VII ----- chorda tympani (br of CN VII) ---- lingualnerve (br of mandibular nerve) ------ submandibular ganglion ---

postsynaptic fibers follow the arteries ---- submandibular gland

Sympathetic innervation is through the externalcarotid plexus (around the external carotid artery-arise from the superior cervical ganglion)


16/89


17/89

SUBLINGUAL GLAND

Lies in the floor of the mouth

Numerous sublingual ducts open with small

foramina on the sublingual fold


18/89


19/89

Innervation of the sublingual gland

Same as the submandibular gland


20/89

NOSE


21/89

Functions of the nose and the nasal cavities are,

Olfaction (sense of smell)

Respiration

Filtration of the dust in the inspired air (the hairs in

the nasal mucosa are called the vibrissae) Humidification and warming of the inspired air

Reception of the secretions from the paranasal

sinuses and nasolacrimal ducts


22/89


23/89


24/89


25/89

EXTERNAL NOSE

Dorsum

Root

Apex

Nares (nostrils, anterior nasal apertures)

Alae of the nose


26/89


27/89

External nose has bony and cartilaginous parts

Bones contributing to the structure of the external nose

Nasal bones

Frontal process of maxilla

Nasal part of frontal bone

Cartilages contributing to the structure of the external nose

Lateral cartilages (paired)

Alar cartilages (paired)

Septal cartilage (single)


28/89


29/89


30/89


31/89


32/89


33/89

CLINICAL NOTE

Nasal fractures

Due to its prominence, the nasal fractures are common

Usually nasal deformity is visible and epistaxis (bleedingthrough the nose) occurs

Severe direct trauma may lead to the fracture of the cribriform

plate of the ethmoid bone If there is a tear of the cerebral meninges, cerebrospinal fluid rhinorrhea

may be observed

May lead to anosmia due to damage to the olfactory nerves


34/89

CLINICAL NOTE

Deviation of the nasal septum

May be due to birth injury or trauma in any age

Common cause of sinusitis due to insufficient

ventilation and drainage of the sinuses

Can be surgically repaired


35/89

Each nasal cavity is divided into

Olfactory area (upper 1/3)

Respiratory area (lover 2/3)


36/89


37/89


38/89


39/89

Posteriorly, each nasal cavity communicates with

the nasopharynx through two openings calledchoana


40/89


41/89


42/89


43/89

Walls of the nasal cavity

Roof

Anterior to posterior

nasal bone

frontal bone

cribriform plate of the ethmoid bone

body of the sphenoid bone

Floor

Floor is formed by the hard palate

Palatine process of maxilla

horizontal plate of the palatine bone.


44/89


45/89

Walls of the nasal cavity (continued)

Lateral

Anterior to posterior frontal process of maxilla

lacrimal bone

superior nasal concha (of the ethmoid bone), middle nasal

concha (of the ethmoid bone), inferior nasal conchaperpendicular plate of the palatine bone

medial lamina of the pterygoid process.

Medial Formed by the nasal septum


46/89


47/89

The medial wall has a smooth surface, whereas the

lateral wall is uneven due to the existance of the

nasal conchae

The spaces between the nasal conchae and the lateral wall

of the nasal cavity are called the meatus.

Superior nasal meatus

Middle nasal meatus

Inferior nasal meatus


48/89


49/89


50/89


51/89


52/89


53/89


54/89


55/89


56/89


57/89

Arterial supply of the nose

The nose has an extensive arterial supply

Sphenopalatine artery (from maxillary)

Anterior and posterior ethmoid arteries (from ophthalmic)

Greater palatine artery (from descending palatine)

Superior labial artery (from facial)

Lateral nasal artery (from facial)


58/89


59/89


60/89


61/89


62/89

Kiesselbachs area

Lies on the anterior part of each side of the nasal septum

This area is rich in capillaries

Here, all five arteries supplying the nose constitute anextensive network of anastomoses

This area is often where profuse bleeding from the nose

occurs


63/89


64/89

Veins of the nose

There is a rich network of veins deep to the mucosa

of the nose

This venous network is important in warming the air

before it enters the trachea and the lungs

Veins drain into

Sphenopalatine vein

Facial vein

Ophthalmic vein


65/89

Nerves of the nose

Sensory innervation of the nose is mainlyfrom the maxillary nerve and the

ophthalmic nerve


66/89

N f h ( i d)


67/89

Nerves of the nose (continued)

Within the epithelium of the olfactory region lies theolfactory cells (neurons)

The peripheral processes of these cells terminate

under the mucosa and are sensitive to odourmolecules in the air

Central processes forms the olfactory nerves (CN I)

Olfactory nerves pass through the cribriform plate of

the ethmoid bone to reac to the olfactory bulb


68/89


69/89


70/89

CLINICAL NOTE


71/89

CLINICAL NOTE

Rhinitis

Excessive nasal secretion due to the swelling and inflamation

of the mucosa as a result of upper respiratory tract infections

or allergic reactions.

Infections may spread to

Paranasal sinuses

Middle ear through the pharyngotympanic tube

Nasopharynx

Lacrimal apparatus and conjunctiva

Anterior cranial fossa through the cribriform plate

CLINICAL NOTE


72/89

CLINICAL NOTE

Epistaxis Bleeding of the nose is called epistaxis

May be due to trauma, hypertension or infections

Is common due to the rich blood supply of the mucosa

The bleeding usually occurs at the Kisselbachs area (anterior

part of the nasal septum).

Mild epistaxis is often due to the tearing of the veins, while profuse bleeding may occur as a result of rupture of the

arteries


73/89

PARANASAL SINUSES

Ai fill d l i ithi th b d th


74/89

Air filled spaces lying within the bones around the

nasal cavity are called the paranasal sinuses

The inner surface of the sinuses are covered by themucosa

Sinuses are named according to the bones they are

located in. Frontal sinuses

Ethmoid sinuses

Sphenoid sinuses Maxillary sinuses


75/89


76/89


77/89


78/89


79/89


80/89


81/89


82/89

Sphenoid sinus


83/89

Sphenoid sinus

Situated within the body of the sphenoid bone

Sinuses of each side is seperated by a bony septum

Drains into the sphenoethmoidal recess

Innervated by the ophthalmic nerve (V1)


84/89

Maxillary sinus


85/89

Maxillary sinus

Lies within the body of the maxilla

Maxillary opening drains into the middle nasal

meatus through the semilunar hiatus

Innervated by the maxillary nerve (V2)


86/89

CLINICAL NOTE


87/89

CLINICAL NOTE

Sinusitis

Infection from the nasal cavity may easily spread to

the sinuses

Resulting inflamation and swelling of the mucosa ofthe sinus(es) may lead to local pain

Swelling may block the opening of sinus and

obstruct the drainage

CLINICAL NOTE


88/89

CLINICAL NOTE

Maxillary sinusitis

Maxillary sinuses are the most commonly infected

sinuses

Due to the edema, its opening may be obstracted

The close relation of the maxillary molar teeth with

the maxillary sinuses may cause problems during the

removal of a molar tooth

Due to its thin wall, a broken root may be forced into the

maxillary sinus


89/89

03 salivary glands, the nose and the associated structures

Documents