head and neck ii

7/27/2019 Head and Neck II

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1. The Major Salivary

Glands

1. Parotid

2. Submandibular

3. Sublingual

2. The Minor Salivary

Glands

Salivary Glands


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Salivary Glands


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Functions

1. Cleanses the mouth due to the bactericidal action of lysozyme and IgA

(immunoglobulin A [one of the immune system's antibodies] )plus the

constant backward flow towards the esophagus.

2. Creates a feeling of oral comfort by it's lubricating action

3. Dissolve food chemicals so that they can stimulate the tongue's taste

buds.

4. Help to form a bolus (ball of food) by the action of mucins thus

facilitating swallowing.

Salivary Glands


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Salivary Glands

5. Contain a digestive enzyme called salivary amylase (ptyalin) which

starts the process of breaking down complex starchy sugars.

6. Buffering (phosphate ions and bicarbonate)

bacteria require specific pH conditions

plaque microorganisms produce acids from sugars

7. Maintenance of tooth integrity

calcium and phosphate ions (ionic exchange with tooth

surface)

8. Tissue repair

bleeding time of oral tissues shorter than other tissues

resulting clot less solid than normal

Re-mineralization


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Major glands

1. Paro t id

2. Submand ibu lar

3. Sub lingual

Salivary Glands


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Salivary Glands

1. Parot id Gland

The parotid salivary glands secrete a serous product only. They aresituated on either side of the head in front of the ears. They have long

ducts (Stensens duct)which open into the mouth opposite the second

molar tooth on either side.


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Salivary Glands

2. Submandibu lar Gland

The submandibular salivary gland secretes a mixed product containing

both serous and mucous secretions although the serous component

is the larger. They are roughly ovoid in shape and are situated below

the mandible (jaw bone) to the left and right. Their ducts (Whartons

duct) open into the floor of the mouth on either side of the tongue's

frenum.


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Salivary Glands

3. Subl ingual Glands

The sublingual glands produce a mainly mucous product. They are

situated just under the back of the tongue again in a left and right pair.

Their ducts (Bartholins duct) open close to those of the

submandibular glands.


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Minor glands

In addition there are numerous smaller groups of salivary gland tissue

scattered diffusely in the submucosa.

The most important are:

1. lingual glands in the submucosa and muscle layers of the dorsalsurface of the tongue

2. minor sublingual glands close to the larger major sublingual glands

(other tongue glands are found on the inferior surface of the tip of the

tongue and on its lateral borders)

3. labial glands on the inner surface of the lips

4. palatine glands in the submucosa of the soft and hard palates

Salivary Glands


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Salivary Glands

5. tonsillar glands in the mucosa associated with the palatine and

pharyngeal tonsils

6. buccal glands in the submucosa lining the cheeks.

7. The labial, sublingual, minor lingual and buccal glands are

composed predominantly of mucous cells, but some serous cells

may be present.

8. The palatine and lateral lingual glands are entirely mucous secreting


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Autonomic Innervation

Parasympathetic

Abundant, watery saliva

Amylase down

Sympathetic

Scant, viscous saliva

Amylase up

Salivary Glands


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Head & Neck

Blood Supply:

Major arteries


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Blood supply- Arteries The arterial supply of the head and neck is derived from the common

carotid, vertebral and subclavian arteries.

The right common carotid arises from the brachiocephalic trunk.

The left common carotid arises from the aortic arch directly.


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Blood supply- Arteries

The common carotid runs upwards in the neck to the upper border of the thyroid

cartilage.

Then it divides into external an internal carotid arteries.


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IThe external caro tid arteryprovides the major blood supply for

the face and mouth.

The two major terminal branches of the external carotid artery are

the maxillary and the facial arteries.


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i. The maxillary artery is the large of the two terminal branches of theexternal carotid artery.

It arises behind the angle of the mandible and supplies the deep structures ofthe face.


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Blood supply- ArteriesMajor branches of the maxillary artery:

1. Infraorbital artery

2. Posterior superior alveolar artery3. Inferior alveolar artery

1

2

3


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1. Infraorbital artery gives branches to anterior and middle superior alveolar

arteries. Their distribution to the maxillary incisors and cuspid teeth and to

the maxillary sinuses.

2. Posterior superior alveolarartery. Its distribution is to the maxillary molar

and premolar teeth and gingiva.

3. Inferior alveolar artery. It descends close to the medial surface of the

mandibular ramus to the mandibular foramen. Before entering the foramen, it

gives off the mylohyoid branch which supplies tissues in the floor of the

mouth.


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ii. The facial artery is

the other major branch of the

external carotid artery.

It enters the face at the inferior

border of the mandible. It

passes forward and upward

across the cheek towards the

angle of the mouth.

It continues upward along the

side of the nose and ends at

the medial canthus (inner

corner) of the eye.


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Blood supply- Arteriesiii. The lingual artery also is a branch of the external carotid artery.

Its distribution is along the surface of the tongue.


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I IThe internal carot id arteryhas a dilation at its root, the carotid sinus.

The internal carotid artery has no branches outside the skull and enters the

skull through the carotid canal.

Inside the skull the internal carotid artery gives off the ophthalmic artery which

supplies the optic nerve, eye, orbit and scalp.


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Head & Neck

Major veins


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Head and neck major veins drainage

The venous drainage of the head and neck begins as drainage of the

brain.

The superior and inferior sagittal sinuses drain to the transverse then

sigmoid sinuses to form the internal jugular vein.

The ophthalmic veins from the orbit drain backwards to the cavernous

sinus or forwards to the facial vein.


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Head and neck major veins

The cavernous sinus drains to the pterygoid plexus of veins, through the

superior petrosal sinus to the transverse sinus and through the inferior petrosal

sinus to the internal jugular vein.

1. Facial vein

2. Cavernous sinus

3. Pituitary plexus

4. Superior petrosal sinus

5. Inferior petrosal sinus

6. Internal jugular vein

7. Transverse sinus

8. Confluence of sinuses


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The maxillary and superficial temporal veins form the retromandibular vein

behind the angle of the mandible.


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Head and neck major veins The retromandibular vein communicates with the external jugular vein and the

internal jugular vein.

The facial vein drains into the internal jugular vein. The internal jugular vein empties into the superior veina cava, which returns blood

from the upper portion of the body to right atrium of the heart.

H d & N k


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Head & Neck

Cranial nerves


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Cranial nerves

The cranial nerves are arranged in 12 pairs, so the two nerves on a pair

are identical in function and structure.

These nerves serve both sensory and motor functions.

The cranial nerves are generally named after the area or function they

serve, and are identified with Roman numerals: I, II, III, IV, V, VI, VII,

VIII, IX, X, XI, XII


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Cranial nerves


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Cranial nerves

I. Olfactory nerve: sensory for the sense of smell.

II. Optic nerve: sensory for the sense of sight.

III. Oculomotornerves: nerves controls muscle of the eye.

IV. Trochleal nerves controls muscles of the eye.


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Cranial nerves

v. Trigeminal nerves: each divide into 3 branches:

1. Ophthalmic branches go to the eyes & forehead.

2. Maxillary branches go to the upper jaw & innervate the teeth & surrounding

tissues.

3. Mandibular branches go to the lower jaw & innervate the teeth & surrounding

tissues.

VI. Abducens nerves control muscles of the eyes.


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Cranial nerves

VII. Facial nerves innervate the muscles of facial expression, salivary glands,

lacrimal glands & sense of taste on the anterior 2/3 rd of the tongue.


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Cranial nerves

VIII. Acoustic nerves: each divide into two branches

a. Cochlear branches, which are concerned with the sense of hearing.

b. Vestibular branches, which are concerned with the sense of balance.

IX. Glossopharyngeal nerves: innervate the parotid glands, sense of taste on the

posterior third of the tongue, and part of the pharynx.

X. Vagus nerves innervate part of the pharynx, larynx and vocal cords, part of the

thoracic and abdominal viscera.

XI. Spinal accessory nerves innervate the shoulder muscles.

XII. Hypoglossal nerves: innervate the muscles concerned with movements of the

tongue.


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Trigeminal nerve

The trigeminal nerve is the primary source of innervations for the oral

cavity.

The trigeminal nerve subdivided into three main branches:

1. Ophthalmic

2. Maxillary

3. Mandibular

T i i l M ill di i i


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Trigeminal nerve- Maxillary division

The maxillary division subdivides to provide the following innervations:

1. The nasopalatine nerve, which passes through the incisive foramen,

supplying the mucoperiosteum (periosteum covered with mucous

membrane) palatal to the maxillary anterior teeth.



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2. The anterior palatine nerve, which passes through the posterior palatine

foramen and forward over the palate, supplying the mucoperiosteum

intermingling with nasopalatine nerve.

3. The anterior superior alveolarnerve supplies the maxillary central lateral and

cuspid teeth, plus their periodontal membrane and gingiva. This nerve also

supplies the maxillary sinus.




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4. The middle superior alveolarnerve supplies the maxillary first and second

premolars, the mesiobuccal root of the maxillary first molar and maxillary sinus.

5. The posterior superior alveolarnerve supplies the other roots of the maxillary

first molar and the maxillary second and third molars, it also branches forward

to serve the lateral wall of the maxillary sinus.

T i i l M dib l di i i


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Trigeminal nerve- Mandibular division

The mandibular division of the trigeminal nerve subdivides into:

1. Buccal nerve

2. Lingual nerve

3. Inferior alveolar nerve, which subdivides into:

Mylohyoid nerve branch

Small dental nerves branches

Mental nerve branch

Incisive nerve branch



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1. The buccal nerve supplies branches to the buccal mucous membrane and the

mucoperiosteum of the maxillary and mandibular molar teeth.

2. The lingual nerve supplies the anterior 2/3 rd of the tongue and gives off

branches to supply the lingual mucous membrane and mucoperiosteum.



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Trigeminal nerve- Mandibular division3. The inferior alveolarnerve subdivides into

Mylohyoid nerve supplies the mylohyoid muscles and the anterior

belly of the digastric's muscle.

Small dental nerves supply the molar and premolar teeth, alveolar

process and periosteum.



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Mental nerve, which moves outward and anteriorly through the mental

foramen and supplies the chin and mucous membrane of the lower lip.

Incisive nerve, which continues anteriorly within the bone and gives offsmall branches to supply the cuspid, lateral and central incisors.

Head & Neck


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Head & Neck

Lymphatic drainage

head and neck ii

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