5 Written Questions

1. "apposition." IDE cells stop to proliferate, except cells at cervical loop. Early bell stage.
   
   First layer of dentin appears at cusp tips and progresses cervically. Columnar cells of IDE elongate and show reverse polarization with nuclei adjacent to stratum inermedium (ameloblasts). nucleus is away from basement membrane.
   
   The boundary between IDE and odontoblasts defines future dentino-enamel jxn.
2. At 4 weeks these anterior vessels have passed through each branchial arch tissue and have dissappeared. The pouches project laterally between each arch.
3. The structure of this tissue is:
   
   1. Overlying oral epithelium
   2. Underlying CT (lamina propria and submucosa) Skin its called epidermis and dermis
4. Inner dental epithelium turns into this after mantle dentin formed.
5. Histology of a structure:
   
   Skin: keratinized start. squamous w/ adnexal structures
   
   Oral mucosa: Moist surface, nonkeratinized w/ small round seromucous glands of lamina propria. Submucosa contains fibers of orbicularis oris.
   
   Vermillion Zone: Very thin keratinized, NO ADNEXAL (can contain sebaceous)

5 Matching Questions

1. Oral Mucosa
2. Amelogenesis imperfecta
3. FOGP 3rd pouch
4. FOGP 2nd pouch
5. Initiation of tooth development

1. a begins at 37 days with horseshoe band of thickened epithelium in upper and lower jaws. PRIMARY EPITHELIAL BAND
2. b This pharyngeal pouch is obliterated by development of palatine tonsil
3. c Formed from ectoderm, unlike viscera, bcuz of head fold
4. d Look up 3 types. item 96, second lecture.
5. e This pharyngeal pouch:
   Dorsally forms inferior parathyroid gland
   Ventrally forms thymus by fusing w. counterpart from other side

5 Multiple Choice Questions

1. A term used to constitute the structure that has enamel organ, dental papilla, and dental follicle.
   1. Dermatome
   2. Dental organ / tooth germ
   3. CT other than head
   4. Stomatodeum
2. Muscles cells in 1ST ARCH become apparent during 5th week and spread into Mn arch into each muscle site's origin in the 6th and 7th week. THESE FORM MUSCLES OF MASTICATION. all relate to developing Mn.
   1. Muscles of facial expression 2nd arch
   2. Tongue formation
   3. Meckel's cartilage
   4. Muscles of mastication 1st arch
3. These are innervated by chorda tympani nerve on anteroir 2/3 of tongue and glosspharyngeal nerve on posterior 1/3.
   
   Seen on places like soft palate and epiglottis, glottis. larynx, pharynx.
   1. Page 32
   2. Taste buds
   3. Enamel cord
   4. Figure 2-12
4. Explanation of a structures red color:
   
   1. Thin epithelium
   2. Epithelium contains ELEIDIN, which is transparent and present in stratum lucidum clear semi-fluid
   3. Blood vessels present near surface.
   1. Sclerotome
   2. Myotome
   3. Enamel cord
   4. Vermillion Zone
5. connective tissue of skin over somite
   1. Submucosa
   2. Ameloblastoma
   3. Tongue
   4. Dermatome

5 True/False Questions

1. Gingival sulcus → These are due to deep rete pegs

   True        False

2. Cervical loop → This is the area where inner and outer dental epithelium meet at rim of enamel organ. Here the cells continue to divide until tooth crown attains its full size. After this, gives rise to epithelium for root formation. (zone of reflexion, never uses this word.

   True        False

3. Tooth Development Stages → Bud stage
   cap stage
   bell stage
   dentinogenesis
   amelogenesis
   crown formation
   root fromation and eruption
   function

   True        False

4. Pituitary gland → This gland is ectodermal in origin and develops from two sources:
   
   Upgrowth from ectodermal roof of stomatodeum called hypophysial diverticulum (rathke's pouch) - adenohypophysis
   
   Downgrowth from neuroectoderm of diencephalon called neurohypophysial diverticulum - neurohypophysis
   
   $th and 5th weeks it connects

   True        False

5. Seperation of 1st branchial arch → This branchial arch seperates into a maxillary process and mandibular arch. 1st branchial groove BELOW Mn arch!!!!

   True        False