Anatomy of the Alveolar Unit and Tongue

Questions and Answers

Which condition is characterized by partial or complete lack of fusion of the maxillary prominence with the medial nasal prominence?

Cleft between the primary and secondary palates (correct)

Robin Sequence

Treacher Collins

22Q11.2 Deletion Syndrome

Which of the following cleft deformities is located anterior to the incisive foramen?

Cleft palate

Cleft upper jaw (correct)

Cleft uvula

Cleft secondary palate

What is the primary defining landmark between anterior and posterior cleft deformities?

Lateral cleft lip

Medial nasal prominence

Maxillary prominence

Incisive foramen (correct)

Which of the following conditions is NOT typically associated with cleft deformities?

Xerostomia Signup and view all the answers

Which of the following accurately describes a characteristic of anterior lingual depression?

It is associated with lateral cleft lip. Signup and view all the answers

What structural feature delineates the site of union between the base and body of the tongue?

V-shaped groove Signup and view all the answers

During which weeks does the occipital myotomes migrate anteriorly into the tongue?

Weeks 5 to 7 Signup and view all the answers

What is the initial embryonic representation of the tongue?

Two lateral lingual swellings and one medial swelling Signup and view all the answers

What type of ossification center is present for each maxilla?

Single ossification center Signup and view all the answers

Which structure is responsible for moving the maxilla in a downward and forward direction?

Deposition at the palatal surface Signup and view all the answers

Which type of tissue develops into the base of the tongue?

Lymphatic tissue Signup and view all the answers

From which embryonic structure do the initial swellings of the tongue originate?

First pharyngeal arch Signup and view all the answers

What describes the process that moves the maxilla forward?

Deposition at anterior surface Signup and view all the answers

What is the most common syndrome associated with cleft lip with or without cleft palate?

Van der Woude syndrome Signup and view all the answers

Which of the following statements describes a potential cause for cleft palate?

Failure of shelves to elevate Signup and view all the answers

Which genetic factor is associated with Van der Woude syndrome?

INTERFERON REGULATORY FACTOR 6 Signup and view all the answers

Infants with DiGeorge syndrome often present with which of the following?

Frequent infections due to thymic aplasia Signup and view all the answers

What is one result of the smallness of the palatine shelves during embryonic development?

Increased risk of cleft palate Signup and view all the answers

What might inhibit the fusion of the palatine shelves?

Micrognathia affecting tongue position Signup and view all the answers

Which of the following conditions is characterized by congenital heart and aortic arch defects alongside learning disabilities?

DiGeorge syndrome Signup and view all the answers

The internal ear is responsible for converting sound waves into what kind of signals?

Nerve impulses Signup and view all the answers

What connects the thyroid to the tongue during its migration?

Thyroglossal duct Signup and view all the answers

At what point in development does the thyroid reach its final position?

Seventh week Signup and view all the answers

Which cells are responsible for producing calcitonin in the thyroid?

C cells Signup and view all the answers

What structure overgrows the second branchial arches during the thyroid's migration?

Hypobranchial eminence Signup and view all the answers

Which thyroid hormones begin to function at the end of the third month?

Thyroxine and triiodothyronine Signup and view all the answers

What type of cells differentiate into cementoblasts?

Mesenchymal cells Signup and view all the answers

What role does the periodontal ligament serve?

Absorbs shock and holds the tooth firmly Signup and view all the answers

Which structure is NOT involved in the thyroid's early development?

Fifth branchial arch Signup and view all the answers

What is the role of the hyaloid vessels during intrauterine life?

They provide vascular support to the retina and lens. Signup and view all the answers

What happens to the interstitial spaces of the hyaloid vessel network during fetal life?

They fill with a transparent gelatinous substance. Signup and view all the answers

What is the fate of the hyaloid canal after the obliteration of the hyaloid vessels during fetal life?

It remains as a remnant known as the hyaloid canal. Signup and view all the answers

Where does mesenchyme invade during the formation of the vitreous body?

Through the optic cup via the choroid fissure. Signup and view all the answers

Which structure is NOT directly involved in the formation of the vascular layer of the retina?

Vitreous body. Signup and view all the answers

At what stage of development do the hyaloid vessels typically obliterate?

At the end of fetal life. Signup and view all the answers

What component largely contributes to the structure of the vitreous body after the hyaloid vessels disappear?

Transparent gelatinous substance. Signup and view all the answers

Which of the following correctly describes the development of the vitreous body?

It is formed by the invasion of mesenchyme into the optic cup. Signup and view all the answers

Study Notes

Alveolar Unit and Tongue Development

The base and body of the tongue connect at the sulcus terminalis, signified by a V-shaped groove.
Alveolar unit development includes a single ossification center for each maxilla.
Displacement occurs due to cranial base bone formation, causing the maxilla to move downward and forward.
Tongue myotomes migrate anteriorly between the 5th and 7th weeks of embryonic development.

Formation of Premaxilla

The premaxilla forms from the fusion of maxillary prominence with two medial nasal processes.
Initially indicated by bilobed diverticulum with two midline elevations.
The hypobranchial eminence overgrows the second branchial arches, connecting with the tongue body.
The thyroid gland remains attached to the tongue during development via the thyroglossal duct.

Tongue Functionality

The tongue begins its functional phase around the third month of gestation.

Thyroid and Dental Development

Follicular cells in the thyroid produce thyroxine and triiodothyronine.
Parafollicular cells derived from the ultimobranchial body produce calcitonin.
Mesenchymal cells near developing teeth differentiate into cementoblasts and form the periodontal ligament, which stabilizes teeth and absorbs shocks.

Cleft Deformities and Craniofacial Defects

The incisive foramen divides anterior and posterior cleft conditions.
Anterior cleft defects include lateral cleft lip and cleft upper jaw due to improper fusion of maxillary and medial nasal prominences.
Posterior cleft conditions, such as cleft palate, arise from palatine shelf fusion failure, possible causes include small shelf size and micrognathia.

Syndromes Associated with Clefting

Van der Woude syndrome is the most frequent genetic condition linked with cleft lip and/or palate, caused by mutations in the IRF6 gene.
Associated defects include congenital heart defects and learning disabilities in infants.

Internal Ear Development

The internal ear functions to convert sound waves and maintain equilibrium.
Otic placodes develop into the internal ear structures.
Hyaloid vessels provide intrauterine blood supply and contribute to the vascular layer of the retina.
The vitreous body forms from interstitial spaces that fill with gelatinous substance, later leaving behind the hyaloid canal after obliteration during fetal life.

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Description

This quiz covers the anatomical aspects of the alveolar unit and its association with the teeth, including the unique features of the tongue, such as the sulcus terminalis. Additionally, it touches on the formation of the maxilla and the migration of occipital myotomes. Test your knowledge on these essential topics in anatomy.