Anatomy of Teeth

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of tissue surrounds and supports the teeth?

Gingiva

Cementum

Alveolar bone

Periodontium (correct)

What is the primary function of enamel?

Supports dentin

Attaches to the cementum of the roots

Acts as a barrier to protect teeth (correct)

Provides sensation to the tooth

What percentage of dentin is composed of hydroxylapatite?

33%

55%

45% (correct)

22%

What two characteristics distinguish dentin from enamel?

Forms throughout life and sensitivity Signup and view all the answers

What attaches to the cementum of the roots by the periodontal ligament?

This part Signup and view all the answers

What fibers attach the cementum overlaying the root to the adjacent cortical surface of the alveolar bone?

Horizontal fibers of the periodontal ligament Signup and view all the answers

Which part of the tongue lies posterior to the palatoglossal arches?

Pharyngeal part of the tongue Signup and view all the answers

What is the function of filiform papillae?

Mechanical effect and tactile sensation Signup and view all the answers

Which type of lingual papillae is not associated with taste buds?

Filiform papillae Signup and view all the answers

Which nerve innervates the taste buds associated with fungiform papillae?

Facial nerve Signup and view all the answers

Where are foliate papillae typically found?

On the lateral margins of the tongue, near the sulcus terminalis Signup and view all the answers

Which type of lingual papillae are the largest?

Vallate papillae Signup and view all the answers

Which muscle of the tongue is not innervated by the hypoglossal nerve?

Palatoglossus Signup and view all the answers

What is the primary function of the palatoglossus muscle?

Elevates the back of the tongue and draws the soft palate inferiorly Signup and view all the answers

Which artery supplies the root of the tongue?

All of the above Signup and view all the answers

What is the function of the superior longitudinal muscles?

Shortens and turns the apex and sides of the tongue upwards Signup and view all the answers

Which vein drains the tongue?

All of the above Signup and view all the answers

What is the function of the inferior longitudinal muscles?

Shortens and turns the apex and sides of the tongue downwards Signup and view all the answers

Which muscle attaches to the lingual septum?

Transverse muscle Signup and view all the answers

What is the blood supply to the palatoglossus muscle?

Ascending palatine artery, a branch of the facial artery Signup and view all the answers

What is the purpose of the sublingual caruncle?

To mark the opening of the submandibular ducts Signup and view all the answers

Which nerve is responsible for the somatic afferents in the areas posterior to the vallate papillae?

Glossopharyngeal nerve Signup and view all the answers

What is the function of the fimbriated folds?

To shape the mucosa of the oral cavity Signup and view all the answers

Which nerve is responsible for the efferent innervation of the tongue, except for the palatoglossal muscle?

Hypoglossal nerve Signup and view all the answers

What is the purpose of the lingual frenulum?

To connect the tongue to the mucosa of the floor of the oral cavity Signup and view all the answers

Which nerve is responsible for the special visceral afferent (taste) in the areas anterior to the vallate papillae?

Facial nerve Signup and view all the answers

What is the function of the Palatine Aponeurosis?

Provides attachment to palatal muscles Signup and view all the answers

What is the origin of the Palatoglossus muscle?

The palatine aponeurosis Signup and view all the answers

What is the function of the Pharyngeal Plexus?

Innervates the muscles of the soft palate Signup and view all the answers

What is the function of the Tensor Veli Palatini?

Supports the integrity of the soft palate Signup and view all the answers

What is the location of the Scaphoid Fossa?

In the pterygoid process of the sphenoid Signup and view all the answers

What is the Spine of Sphenoid?

A process of the sphenoid bone Signup and view all the answers

What is the innervation of the Palatopharyngeus muscle?

The pharyngeal plexus Signup and view all the answers

What is the relationship between the Tensor Veli Palatini and the Palatine Aponeurosis?

The Tensor Veli Palatini is a muscle that inserts into the Palatine Aponeurosis Signup and view all the answers

Study Notes

Tooth Structure

Teeth are attached to the cementum of the roots by the periodontal ligament
Gingiva covers the alveolar bone
Enamel is very hard, white to off-white, and highly mineralized, acting as a barrier to protect teeth
Enamel can be degraded by acids from food and drink
Dentin is yellow in appearance and greatly affects the color of the tooth due to the translucency of enamel
Dentin is less mineralized and less brittle than enamel, and is necessary for supporting enamel
Two main characteristics distinguishing dentin from enamel are that it forms throughout life and is sensitive

Periodontium

Periodontium refers to the tissues surrounding and supporting teeth
The four principal components of the periodontium are:
- Gingiva
- Periodontal ligament
- Cementum
- Alveolar bone
Alveolar bone is surrounded by gingival subepithelial connective tissue
Cementum overlays the root and is attached to the adjacent cortical surface of the alveolar bone by the alveolar crest, horizontal fibers of the periodontal ligament, and oblique fibers of the periodontal ligament

Palatine Aponeurosis

Supports the integrity of the soft palate
Provides attachment to palatal muscles
Composed of the expanded tendons of the tensor veli palatini and encloses the musculus uvulae
Thin, firm fibrous plate attached to the posterior border of the hard palate
Is an autonomous neural crest structure
Supports the muscles of the soft palate and gives strength

Scaphoid Fossa and Spine of Sphenoid

Scaphoid fossa is a small, oval, shallow depression in the pterygoid processes of the sphenoid, above the pterygoid fossa
Spine of sphenoid is a triangular process that projects from the postpart of each great wing of the sphenoid, fitting into the angle between the squama and petrous portion of the temporal bone

Muscles of the Palate and Pharynx

Palatoglossus muscle:
- Innervation: Pharyngeal plexus
- Origin: Palatine aponeurosis
- Insertion: Side of the tongue
- Action: Elevates the back of the tongue and draws the soft palate inferiorly, closing the oropharyngeal isthmus
Palatopharyngeus muscle:
- Innervation: Pharyngeal plexus
Pharyngeal plexus:
- Innervates all muscles of the soft palate except the tensor veli palatini
- Formed by pharyngeal branches from the glossopharyngeal nerve and the vagus nerve

Tongue

Connected to the mucosa of the floor of the oral cavity via the lingual frenulum
Sublingual folds lateral to the lingual frenulum are formed by sublingual glands and ducts of submandibular glands, shaping the mucosa
Sublingual caruncle is located at the confluence of the sublingual folds and the lingual frenulum
Fimbriated folds flank the lingual frenulum
Deep lingual veins are visible deep to the surface of the mucosa between the lingual frenulum and the fimbriated folds

Innervation of the Tongue

Except for the palatoglossal muscle, the tongue is entirely innervated by the hypoglossal nerve
Somatic afferents:
- Areas anterior to the vallate papillae: Lingual nerve
- Areas posterior to the vallate papillae: Glossopharyngeal nerve
Taste buds are innervated by:
- Areas anterior to the vallate papillae: Facial nerve (chorda tympani)
- Areas posterior to the vallate papillae: Glossopharyngeal nerve

Lingual Papillae

Projections of mucosa on the presulcal part of the dorsum
Four types:
- Fungiform
- Filiform
- Foliate
- Vallate
All carry taste buds except for the filiform papillae

Extrinsic Tongue Muscles

Palatoglossus muscle:
- Elevates the back of the tongue and draws the soft palate inferiorly, closing the oropharyngeal isthmus
- Aids in the initiation of swallowing
Innervation: Pharyngeal branch of the vagus nerve
Motor fibers from the cranial accessory nerve

Intrinsic Tongue Muscles

Only attach to other structures in the tongue
Named by direction in which they travel
Affect the shape and size of the tongue
Have a role in facilitating speech, eating, and swallowing
Motor innervation via the hypoglossal nerve
Four paired intrinsic tongue muscles:
- Longitudinal
- Transverse
- Vertical
- Inferior longitudinal

Blood Supply of the Tongue

Arteries of the tongue:
- Lingual artery
- Dorsal lingual artery
- Root of the tongue is also supplied by:
  - Tonsillar and ascending palatine branches of the facial artery
  - Ascending pharyngeal artery
Veins of the tongue:
- Lingual vein
- Union of dorsal lingual vein, deep lingual vein, and vena comitans of the hypoglossal nerve

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the structure and composition of teeth, including enamel, dentin, and the periodontal ligament. Learn about the properties and functions of each component.