GENERAL STRUCTURE OF THE GASTROINTESTINAL TUBE Mucous membrane (tunica mucosa): Folds (plicae), smaller processes (papillae), villi (villi intestinales). Lamina epithelialis, lamina propria mucosae,lamina muscularis mucosae. Folliculi lymphatici solitarii or folliculi lymph. aggregati – Peyer’s patches. Submucous tissue (tunica submucosa) The nervous plexus is called plexus submucosus Meissneri. Muscular tissue (tunica muscularis) Is striated musculature or smooth. Internal circular and external longitudinal. The nervous plexus myentericus Auerbachi. Outer layer Tunica adventitia or tunica serosa (visceral peritoneum). Glands of the GIT Intramural (e.g. goblet cells) or extramural glands. ORAL CAVITY (CAVUM ORIS) Rima oris Vestibulum oris Cavum oris proprium Vestibule of the mouth Labia oris - labium superius – sulcus nasolabialis, philtrum - tuberculum labii superioris cheiloschisis (cleft lip) gnathoschisis (cleft jaw) palatoschisis (cleft palate) - labium inferius - sulcus mentolabialis pars intermedia fornix vestibuli superior et inferior - frenulum (bridle) anguli oris glandulae labiales m. orbicularis oris. Buccae - glandulae buccales, m. buccinator, papilla parotidea - ductus parotideus. Raphe pterygomandibularis –mandibular anesthesia Gingiva - gingiva proper (attached gingiva) - pars fixa gingivae - pars libera gingivae Alveolar mucosa – separated from the gingiva by the mucogingival border The oral cavity proper (cavum oris proprium) diaphragma oris - mylohyoid muscles, geniohyoid muscles, anterior belly of the digastric muscle glandula submandibularis glandula sublingualis Salivary glands Glandulae salivariae minores - labiales, buccales, molares, palatinae, linguales Glandulae salivariae majores - sublingualis, submandibularis and parotis Glandula submandibularis – ductus submandibularis – caruncula sublingualis Glandula sublingualis– plica sublingualis, ductus sublingualis major, ductus sublinguales minores Glandula parotis - fossa retromandibularis, fascia parotideomasseterica.Tractus angularis separates the gland from the trigonum submandibulare. Parotid plexus - the CN VII – nervus facialis. Ductus parotideus - papilla parotidea Glandula parotis accessoria The palate (palatum) The hard palate (palatum durum) - the palatine processes of the maxillae and horizontal plates of the palatine bones Raphe palati Papilla incisiva Plicae palatinae transversae Glandulae palatinae The soft palate(palatum molle, velum palatinum) Aponeurosis palatina Uvula palatina Arcus palatoglossus et arcus palatopharyngeus Tonsilla palatina – fossa (sinus) tonsillaris, plica triangularis, fossa supratonsillaris– plica semilunaris, 12 – 15 cryptae tonsillares– tonsillitis – tonsillar pegs, paratonsillar vein - tonsillectomy. Muscles of the soft palate: Musculus tensor veli palatini – CN V. M. levator veli palatini M. uvulae M. palatoglossus M. palatopharyngeus plexus pharyngeus (CN IX., X.). Tongue (lingua) Corpus linguae Radix linguae - tonsilla lingualis Dorsum linguae - sulcus terminalis (ductus thyroglossus), sulcus medianus Papillae filiformes, fungiformes, foliatae, valatae, (calliculi gustatorii) Apex linguae Margines linguae Facies inferior linguae - frenulum linguae, plicae fimbriatae, plica sublingualis -caruncula sublingualis Plica glossoepiglottica mediana and two plicae glossoepiglotticae laterales - valleculae epiglotticae DENTITION Dentes permanentes 32 teeth: 2 incisors, 1 canine, 2 premolars and 3 molars in one quadrant of the complete permanent dentition. Description of the tooth: The crown (corona dentis) The masticatory s. (facies occlusalis) - tubercula dentalia The contact ss. (facies approximales) - facies mesialis, facies distalis The vestibular s. (facies vestibularis) - f. labialis, f. buccalis The oral s. (facies oralis) - f. palatina, f. lingualis The neck ( collum dentis) - gingivodental cap The root (radix dentis) is inserted into the alveolus of the jaw. Some teeth have one root, others 2 or 3. The pulp cavity (cavitas dentis) - canalis radicis - foramen apicis dentis Structure of the tooth Dentin (dentinum) formed by odontoblasts, 70% of inorganic substances. Enamel (enamelum) 97% of inorganic substances. Cement (cementum) formed by the fibrous bone. Pulp (pulpa dentis) - loose connective tissue, vessels and nerves. Fixation of the tooth Periodontium - collagen Sharpey’s fibers Parodontium - gum, periosteum, alveolus, periodontium, cement Morphology of individual teeth Dentes incisivi -1 root, crown - occlusal edge. The largest incisor is upper medial one. The root is long, conical and flat from sides. Dentes canini are long teeth with one root, the crown projects in the acute spike with cutting edges at its sides. The root is long and flat from sides. The upper canine is bigger than lower. Dentes premolares has 2 tubercles on its occlusal surface (one vestibular, the other lingual). Upper premolars have both tubercles of the same size, the lower have the bigger vestibular tubercle. Premolars have one root except the upper first premolar that has two roots – palatinal and buccal. Dentes molares - the occlusal surface of upper molars has 4 tubercles separated by the deep groove. The size of molars decreases distally. The crown has 2 buccal and 2 palatinal tubercles. The groove has the shape of the letter H. Upper 1^st molar is the strongest and biggest tooth of the upper arch. The additional tubercle may be on its palatine side (tuberculum anomale Carabelli). Upper 2^nd and 3^rd molar have often only 2 tubercles. The occlusal surface of the lower molars has the quadrangular shape. The groove has the shape of the cross. The 1^st molar has often 5 tubercles the 5^th lies distally. Third molars have variable crowns and may be impacted. Upper molars have 3 roots (2 vestibular and 1 palatinal), lower have 2 roots (1 mesial and 1 distal) Dentes decidui Crowns of milk teeth are lower and wide. They are of white colour with the blue shade. Roots are narrower and sharper and are more distant because surround primordia of crowns of permanent teeth. Dental formula i1, i2, c, m1, m2 (I, II, III, IV, V) – deciduous teeth I1, I2, C, P1, P2, M1, M2, M3 (1, 2, 3, 4, 5, 6, 7, 8) – permanent teeth Dentition is divided into 4 quadrants: 1|2 5|6 4|3 8|7 permanent deciduous 23 = upper left permanent canine 85 = lower right milk second molar Occlusion Upper dental arch has a shape of the half of the oval, lower arch of parabola. Therefore the teeth do not meet each other exactly. Normally the crowns of the upper teeth are slightly oblique toward the vestibule and those of the lower teeth toward the tongue. Thus the cutting edges of the front teeth bypass each other like the blades of a pair of scissors. In the premolars and molars the vestibular tubercles of upper teeth overhangs those of lower teeth. Each tooth is in contact with two opposing teeth, with the principal antagonist (over a large contact area) and with an adjacent secondary antagonist. Only the 1^st lower incisor and the third upper molar have a single antagonist. In rare cases the cutting edges are opposite each other like a forceps. In prognathism – the upper jaw is displaced anteriorly; in progenism – the lower jaw is ventral the upper one. Eruption The primordia of the deciduous teeth are already in a newborn child. The growing root pushes the crown to the gum, this atrophies and the tooth erupts. I 6^th-8^th month II 8^th -12^th month III 16^th -20^th month IV 12^th -16^th month V 20^th -36^th month Exchange of the teeth Crowns of the permanent teeth grow orally and elicit resorption of alveoli of milk teeth and their roots. Roots of milk teeth shorten and disappear, the rest of the crown releases from the gum. 1 7^th -8^th year 2 8^th -9^th year 3 11^th -13^th year 4 9^th -11^th year 5 11^ th -13^ th year 6 6^th -7^th year 7 12^th -14^th year 8 17^th -40^th year