Term
What are the boundaries of the vestibule?
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Definition
The Vestibule: is a slit-like space, bounded externally by the lips and cheeks; internally by the gums and teeth. It receives the secretion from the parotid salivary glands.
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Term
How does the vestibule communicate with the mouth cavity proper?
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Definition
| It communicates when the jaws are closed, with the mouth cavity proper by an aperture on either side behind the 3rd Molar teeth, and by narrow clefts between opposing teeth. |
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Term
How does the mouth cavity proper communicate with the pharynx?
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Definition
It communicates with the pharynx by a constricted aperture termed the isthmus of the fauces.
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Term
What are the boundaries of the mouth cavity proper?
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Definition
Is bounded laterally and in front by the alveolar arches with their teeth
It communicates with the pharynx by a constricted aperture termed the isthmus of the fauces.
Its roof is formed by the hard and soft palates
The greater part of the floor is formed by the tongue, the remainder by the reflection of the mucous membrane from the sides and under surface of the tongue to the gum lining the inner aspect of the mandible |
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Term
What are the components of the lips?
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Definition
| The Lips: Two fleshy folds which surround the orifice of the mouth, are formed externally of skin and internally of mucous membrane |
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Term
What lies in between the external skin layer and internal mucous membrane of the lips?
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Definition
The Orbicularis oris muscle, the labial vessels, some nerves, areolar tissue, and fat, and numerous small labial glands
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Term
Cheeks are continuous in front with the lips and they are composed externally of skin and internally of mucous membrane. What lies between these two layers?
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Definition
| A muscular stratum, besides a large quantity of fat, areolar tissue, vessels, nerves, and buccal glands. |
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Term
What are the boundaries of the hard palate?
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Definition
| The Hard Palate: is bounded in front and at the sides by the alveolar arches and gums; behind, it is continuous with the soft palate. It is covered by a dense structure, formed by the periosteum and mucous membrane of the mouth, which are intimately adhered. The bones forming the hard palate are the palatine processes of the maxilla and the horizontal plates of the palatine bone. |
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Term
| What are the boundaries of the soft palate? |
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Definition
| The Soft Palate: is a movable fold, suspended like a curtain from the posterior border of the hard palate, and forming an incomplete septum between the mouth and pharynx. It consists of a fold of mucous membrane enclosing muscles, an aponeurosis, vessels, nerves, adenoid tissue, and mucous glands. Its upper border is attached to the posterior margin of the hard palate, and its sides are blended with the pharynx. Its lower border is free. Hanging from the middle of its lower border is a small, conical, pendulous process, the palatine uvula. |
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Term
What does the mucous membrane of the soft palate enclose? |
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Definition
It encloses muscles, an aponeurosis, vessels, nerves, adenoid tissue, and mucous glands.
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Term
What is the palatine aponeurosis?
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Definition
| Attached to the posterior border of the hard palate is a thin, firm fibrous lamella which supports the muscles and gives strength to the soft palate. It is thicker above than below, where it becomes very thin and difficult to define. Laterally it is continuous with the pharyngeal aponeurosis. |
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Term
What is levator veli palatini? |
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Definition
Levator veli palatini: Origin: Inferior surface of the petrous part of the temporal bone and the medial surface of the cartilage of the auditory tube
Insertion: to the Palatine aponeurosis
Action: Elevates the soft palate and opens up the auditory tube
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Term
What is the tensor veli palatine? |
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Definition
Tensor veli palatini arises from the scaphoid fossa of the medial pterygoid plate, spine of sphenoid bone and cartilage of the auditory tube. It curves medially around the pterygoid hamulus and gets inserted to the palatine aponeurosis. It tenses the soft palate (depresses) and opens the mouth of auditory tube during swallowing or yawning.
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Term
What is the palatopharyngeus?
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Definition
Palatopharyngeus: It has two parts- anterior and posterior- with the levator palati in between. The posterior part belongs to superior constrictor of pharynx. It origins from the palatine aponeurosis and runs backwards in the lateral wall of the pharynx to be inserted to the pharyngeal raphe. Its fibers produce the ‘ridge of passavant’ which is well marked in patients with cleft palate.
The anterior part arises from palatine aponeurosis and crest and is inserted to the posterior border of the thyroid cartilage.
Palatopharyngeus prevents food from entering the nasopharynx during second stage of deglutition by bringing the soft palate into opposition with the posterior pharyngeal wall shutting the nasopharynx during deglutition and speech. |
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Term
| What are the musculus uvulae? |
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Definition
| musculus uvulae: two muscles close to the midline. Origin- posterior nasal spine. Insertion to the mucous membrane of the uvula. Action- it shortens the uvula and pulls it to its own side. In paralysis of one, the uvula deviates to the opposite side |
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Term
What is the nerve supply of all the muscles of the soft palate?
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Definition
Nerve supply of the muscles of the soft palate: All are supplied by the cranial accessory nerve through the pharyngeal plexus except the tensor veli palatine which is supplied by the mandibular nerve through a branch from the otic ganglion (without synapsing).
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Term
Describe the mucous membrane of the soft palate. |
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Definition
Mucous Membrane— The mucous membrane of the soft palate is thin, and covered with stratified squamous epithelium on both surfaces, excepting near the pharyngeal ostium of the auditory tube, where it is columnar and ciliated
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Term
What are the vessels and nerves supplying the soft palate?
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Definition
Vessels and Nerves.—The arteries supplying the palate are the Greater (descending) palatine branch of the internal maxillary, the ascending palatine branch of the external maxillary, and the palatine branch of the ascending pharyngeal. The veins end chiefly in the pterygoid and tonsillar plexuses. The lymphatic vessels pass to the deep cervical glands. The sensory nerves are derived from the palatine and nasopalatine nerves and from the glossopharyngeal.
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Term
How does carcinoma of the lips normally spread?
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Definition
| Carcinoma of the lips usually involves the lower lip and the cancer cells metastasize through the lymph vessels to reach the submandibular (from the lateral part of the lip) and submental (from the medial part) lymph nodes. |
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Term
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Definition
Cyanosis is a dark bluish or purplish coloration of the lips and mucous membrane resulting from deficient oxygenation of capillary blood.
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Term
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Definition
Gingivitis is a form of periodontal disease. Periodontal disease involves an inflammation and/or infection that results in the destruction of the supporting tissues of the teeth, including the gingiva (gums), the periodontal ligaments, and the tooth sockets (alveolar bone). Gingivitis is the inflammation of the gums, and often includes redness, swelling, bleeding, exudation, and sometimes pain.
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Term
How does one anaesthetize the neopalatine nerves?
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Definition
The nasopalatine nerves can be anesthetized by injecting anesthetic in to the incisive foramen in the hard palate. The affected tissues are the palatal mucosa, the lingual gingivae and the alveolar bone, maxillary teeth and hard palate.
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Term
How can the greater palatine nerve be anesthetized?
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Definition
The greater palatine nerve can be anesthetized by injecting anesthetic into the greater palatine foramen. The nerve emerges between the 2nd and 3rd molar teeth. The affected tissues are the palatal mucosa, the lingual gingivae posterior maxillary canine teeth and the
underlying bone of hard palate.
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Term
What are the parts of the tongue?
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Definition
It has a root, apex and body
The root is attached to the mandible and hyoid bone through the muscles
The apex of the tongue is free and placed anteriorly
Body: has two surfaces (Dorsal and ventral) and two lateral borders.
The dorsum of the tongue has papillae and it is divided into anterior two thirds and posterior one third.
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Term
What is the sulcus terminalis?
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Definition
The junction between the anterior 2/3 and posterior 1/3 of the tongue is indicated by “V” shaped suclus terminalis. The apex of the sulcus terminalis is at the foramen cecum, a blind depression. This depression is the site of attachment of thyroglossal duct during development of thyroid gland.
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Term
In what regions of the tongue do the main taste sensations predominate?
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Definition
· Sweet sensation is predominant at the tip of the tongue
· Salt on the sides of the tongue
· Sour and bitter on the posterior part of the tongue
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Term
What are some features of the mucous membrane of the tongue?
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Definition
The mucus membrane loosely covers the inferior surface of the tongue and presents the following features:
v Frenulum linguae (a median fold of mucous membrane)
v Deep lingual vein shining through the mucous membrane placed lateral to the frenulum
v Plica fimbriata: Fimbriated fold of mucus membrane lateral to the deep lingual veins
v Submandibular ducts open on the sublingual papilla
v Sublingual gland elevation is seen on either side of the median plane in the floor of the mouth.
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Term
| How can one administer drugs quickly via the tongue? |
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Definition
· When quick absorption of a drug is necessary, then it can be placed under the tongue in the floor of the mouth. It is absorbed directly into the lingual vein. This is used to place nitroglycerine tablets that relieve angina pectoris symptoms by dilating the vessels.
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Term
What is the median groove of the dorsum of the tongue?
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Definition
Median groove on the dorsum of the tongue in its anterior two thirds represents the bilateral origin from two lingual swellings of the first arch.
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Term
What is the palatoglossus?
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Definition
Palatoglossus: It extends between the soft palate and the side of the tongue
It elevates the tongue during the first stage of swallowing. Palatoglossus is supplied by the pharyngeal plexus, fibers derived from the cranial part of accessory nerve through vagus. |
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Term
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Definition
Hyoglossus: it is a quadrilateral muscle which extends between the hyoid bone and the side of the tongue. It depresses the corresponding side of the tongue.
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Term
What structures lie superficial to the hyoglossus?
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Definition
The following structures lie superficial to the hyoglossus muscle:
1. Lingual nerve
2. Submandibular ganglion
3. Submandibular gland
4. Submandibular duct
5. Hypoglossal nerve
6. Veins accompanying the hypoglossal nerve
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Term
What structure lie deep to the hyoglossus?
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Definition
· Glossopharyngeal nerve
· Stylohyoid ligament
· Lingual artery and accompanying vein
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Term
What happens when the genioglossus is paralyzed? |
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Definition
Genioglossus: This is a fan shaped muscle which arises from the genial tubercle and is inserted from the apex to the root of the tongue on either side of the median fibrous septum.
It protrudes the tongue out of the mouth. Therefore in hypoglossal nerve paralysis, the tongue is deviated to the paralyzed side.
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Term
What is the superior longitudinal muscle?
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Definition
Superior longitudinal: It lies nearer to the dorsum of the tongue. Upon contraction it curls the tip of the tongue upwards as in touching the hard palate from the tip of the tongue.
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Term
What is the inferior longitudinal muscle?
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Definition
Inferior longitudinal: It lies nearer to the inferior surface of the tongue. It turns the tip of the tongue downwards as in touching the back of incisor teeth.
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Term
What are the transverse and vertical muscles of the tongue?
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Definition
Vertical muscle of tongue: extends vertically from the dorsum to the inferior surface of the tongue. It flattens the tongue
Transverse muscle of tongue: It extends from the fibrous median septum to the side of the tongue and upon contraction it thickens the tongue.
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Term
What are the intrinsic muscles of the tongue supplied by?
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Definition
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Term
Summarize the nerve supply of the tonuge.
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Definition
Nerve supply of the tongue:
It is supplied by the following six nerves:
1. Lingual nerve ( sensory to the anterior two thirds of the tongue excluding the vallate papillae)
2. Chorda tympani ( taste sensation from the anterior two thirds of the tongue except the region of the vallate papillae(circumvallate papillae)
3. Glossopharyngeal nerve ( sensory and taste to posterior one third of the tongue and region over the vallate papillae immediately anterior to the sulcus terminalis
4. Internal laryngeal nerve( a branch of superior laryngeal nerve of vagus) supplies the small area in front of the epiglottis by sensory and taste fibers
5. Hypoglossal nerve supplies seven muscles
6. Palatoglossus is supplied by the pharyngeal plexus |
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Term
What is the arterial supply of the tongue?
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Definition
Blood supply:
It is supplied by the lingual artery:
Lingual artery gives the dorsal lingual branches to the posterior one third of the tongue.
It supplies the anterior two thirds of the tongue and continues as deep lingual artery to the tip of the tongue.
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Term
What is the venous drainage of the tongue?
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Definition
Venous drainage: It is drained into the lingual vein. There are two sets of veins. One set accompanies the lingual artery deep to the hyoglossus muscle and continues as lingual vein and opens into the internal jugular vein. The other set accompanies the hypoglossal nerve superficial to the hyoglossus and either opens into the lingual vein or facial vein.
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Term
| What is lymphatic drainage of the tip of the tongue? |
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Definition
| The tip is drained into the submental lymph nodes and subsequently to upper or lower deep cervical lymph nodes. |
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Term
What is the lymphatic drainage of the posterior third of the tongue?
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Definition
The posterior one third of the tongue is drained into the upper deep cervical lymph nodes of both sides
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Term
What is the lymphatic drainage of the medial part of the anterior 2/3s of the tongue?
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Definition
The medial part of anterior two thirds is drained into the upper and lower deep cervical lymph nodes of both sides
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Term
What is the lymphatic drainage of the lateral 2/3s of the tongue?
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Definition
The lateral part of the anterior two thirds of the tongue is drained into the submandibular lymph nodes of the same side and later drained into either upper or lower deep cervical nodes.
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Term
What do the lower deep cervical lymph nodes mostly drain into?
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Definition
The majority of vessels which reach the lower deep cervical lymph nodes are drained into the jugulo-omohyoid node. This node is called as the lymph node of the tongue. This is a sentinel node which forces the physician to do further tests to rule out the possibility of cancer of the tongue. Jugulo-omohyoid is one of the lower deep cervical lymph nodes.
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