Upper GIT - Foregut Anatomy Lecture Notes PDF

ANATOMY | TRANS 3 LE Upper GIT - Foregut MA. JENINA ANGELA ESGUERRA-PACULAN, MD | 01/22/2024 | Version #1...

ANATOMY | TRANS 3 LE Upper GIT - Foregut MA. JENINA ANGELA ESGUERRA-PACULAN, MD | 01/22/2024 | Version #1 04 OUTLINE An 8-year-old boy accidentally swallowed a ₱10 coin about 2 hours prior to ER consult I. Oral Region E. Appendix Since the patient swallowed the coin, it is probably in the A. Oral Cavity F. Footer esophagus. B. Lips, Cheeks, and G.Summary of Font Size Child was brought to the ER 2 hours after the incident so the Gingivae III. Review Questions coin did not block the airway. C. Teeth IV. How to add QR code D. Palate V. References OVERVIEW OF THE GASTROINTESTINAL SYSTEM E. Tongue VI. Formative quiz Three main functions: II. Esophagus VII. Appendix ○ Transport food A. General Formatting ○ Absorb food B. Figure ○ Maintain health and survival of individual (together with 💬 C. Tables accessory organs) D. Additional tables Food comes in through the mouth and goes down to the Must Lecturer Book Previou Youtube esophagus, stomach, small bowel, to your large colon, and exits through the anal canal ❗️ Know 💬 📖 📋 s Trans 🔺 Video I. ORAL REGION SUMMARY OF ABBREVIATIONS AOG Age of Gestation LEARNING OBJECTIVES ✔ Defining the functions of the digestive system. ✔ Naming, in consecutive order, the component parts of the digestive tract. ✔ Describing the anatomy of the oral cavity, with respect to its walls and boundaries, communication with the oropharynx, and its subdivisions. ✔ Describing the general structure of a tooth. ✔ Stating the approximate time and order of eruption of the two (2) sets of teeth and the total number of each set. ✔ Describing the gross structure of the tongue, including its innervation (sensory and motor), blood supply, and lymphatic drainage. ✔ Describing the actions of the extrinsic muscles of the tongue. ✔ Describing the structure of the soft and hard palate. Figure 2. Overview of the Oral Cavity[PPT] ✔ Identifying the openings of the salivary glands. ✔ Locating the palatine tonsils and describing their A. ORAL CAVITY (MOUTH) innervation, blood supply, and lymphatic drainage. ✔ Describing the gross anatomy (structure, anatomic relations, blood supply, lymphatic drainage, and innervation) of the esophagus. ✔ Locating the stomach and giving its anatomical relations. ✔ Describing the shape and parts of the stomach including some variations. ✔ Identifying the peritoneal attachments of the stomach. ✔ Describing the gross structure of the mucosa of the stomach. ✔ Stating mechanisms that serve sphincteric functions at the cardiac orifice of the stomach. ✔ Stating how the pyloric sphincter is formed, noting possible signs and symptoms in pyloric stenosis. ✔ Describing the innervation, blood supply, and lymphatic drainage of the stomach. Figure 3. Left Retromolar Region[PPT] I. CLINICAL CORRELATION Thin dotted line: Internal oblique ridge; Solid line: External oblique ridge; BM: Buccal mucosa; RP: Retromolar pad; T: Tongue Two parts: ○ Oral vestibule ○ Oral cavity proper Figure 1. Radiograph of patient who swallowed a ₱10 coin[PPT] LE 4 TG 18 | Constantino, Continuado, Contreras, Crave, TE | C. Cruz, G. Cruz AVPAA | C. Cabuyao, C. PAGE 1 of 14 TRANS 2 Crescini, Cristobal Cambas, M. Carating ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD NEUROVASCULATURE OF THE LIPS Figure 4. Oral Cavity[PPT] Figure 6. Superficial Arteries of Face[Moore] 💬 ORAL VESTIBULE Slit-like space between the teeth, gingiva and lips and The superior and inferior labial arteries anastomose with the cheeks Communicates with the exterior through the oral fissure or ○ 💬 each other at the lips forming an arterial ring If you grasp your lips in between two fingers, you can feel the pulsation of this arterial ring the opening (mouth) Size of the fissure is controlled by the perioral muscles Table 1. Summary of the Neurovasculature of the Lips ○ Orbicularis oris - sphincter of the oral fissure Lymphatic ○ Buccinator, risorius, depressors and elevators of the lips - Arteries Innervation Drainage dilators Upper Lip Superior Superior (Including ❗️ ORAL CAVITY PROPER Boundaries of the Oral Cavity proper ○ Lateral and Anterior limitation: teeth and dental arches labial branches of the facial labial branches of the lateral lower lip) Submandibula ○ Posterior: Communicates with oropharynx and infra-orbital r lymph nodes ○ Roof: Hard and Soft palate infra-orbital nerves of CN Space between the upper and lower dental arches arteries V2 Fully occupied by tongue when mouth is closed Lower Lip Inferior Inferior labial (Medial lower B. LIPS, CHEEKS, GINGIVAE labial branches of lip) Submental LIPS branches of the mental lymph nodes the facial nerves of CN Mobile musculo-fibrous folds surrounding the mouth and mental V3 Extends: arteries ○ Laterally: Nasolabial sulci and nares ○ Inferiorly: Mentolabial sulcus GINGIVAE (GUMS) Contains: ○ Orbicularis oris Controls entry and exit from the mouth and the upper alimentary and respiratory tracts ○ Superior and inferior labial muscles, vessels, and nerves Covered externally by skin, and internally by mucous membrane Functions: ○ Act as the valves of the oral fissure ○ Grasping food, sucking different kinds of liquids, keeping food out of the vestibule, forming speech, and osculation (kissing) Figure 7. Oral Vestibule and Gingivae[Moore] Figure 5. Labial and Lingual Frenula[PPT] Composed of fibrous tissue covered with mucous membrane Labial and Lingual Frenula Gingiva Proper ○ Superior and inferior labial frenula ○ Firmly attached to the alveolar process of the maxilla, ○ Free-edged folds of the mucous membrane in the midline mandible, and necks of the teeth extending from the vestibular gingiva to the mucosa of ○ Normally pink, stippled. and keratinizing the upper and lower lips ○ Superior and Inferior Lingual Gingiva ○ Smaller frenula may appear laterally at premolar Gingiva proper closest or adjacent to the tongue vestibular regions ○ Maxillary Gingiva Gingiva proper adjacent to the lips ○ Mandibular (Buccal) Gingiva Gingiva proper adjacent to the cheeks Alveolar Mucosa ○ Red, shiny, and non-keratinizing ANATOMY Upper GIT - Foregut PAGE 2 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD ○ 💬 Attached to the lips INNERVATION Figure 8. Innervation of oral cavity[Moore] Figure 11. Sensory Innervation of Gingiva[Moore] (Nerves supplying the gingiva underlying the alveolar bone and periodontium) Upper part of oral cavity ○ Supplied by superior labial branches of the infraorbital 💬 Periodontium nerves ○ Surrounds the root of the tooth anchoring it to the tooth ○ Superior alveolar Nerves sockets Branches of the maxillary branch of the trigeminal SENSORY INNERVATION OF GINGIVA, TONGUE, AND nerve PALATAL MUCOSA Lower part of oral cavity ○ Supplied mostly by the inferior labial branches of the ○ 💬 mental nerves Inferior alveolar nerve Branches of the mandibular branch of the trigeminal nerve C. TEETH Incise, reduce, and mix food with saliva during mastication Help sustain themselves in the tooth sockets by assisting the development and protection of the tissues that support them Participate in articulation Two kinds: ○ Deciduous (primary) ○ Permanent 32 teeth in adults surrounded by alveolar bones Alveolar bone proper Adjacent to cementum and surrounding bone Resorbs along the loss of teeth Keeps the structure of oral cavity ○ Gums regress after tooth extraction or loss DECIDUOUS TEETH Figure 9. Innervation of Mouth and Teeth[Moore] Innervations in top left image: ○ Yellow (posterior region): Vagus nerve ○ Green area: Glossopharyngeal nerve ○ Pink area (tongue): Lingual nerve ○ Blue area (gingiva anterior to incisors): Mental nerve Figure 12. Deciduous Teeth[Moore] Figure 10. Innervation of oral mucosa[PPT] Children have 20 deciduous teeth ○ Supplied by superior labial branches of the infraorbital nerves Branches of the maxillary branch of the trigeminal nerve ANATOMY Upper GIT - Foregut PAGE 3 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD PARTS OF THE TOOTH Figure 13. Baby Teeth Chart[Google] Figure 17. Longitudinal section of an incisor and molar[Moore] Crown ○ Projects from the gingiva ○ Biting surface ○ Hardest substance in the human body (enamel) Figure 14. Teeth Chart[Moore] ○ When root canal procedure is done, this portion is replaced TYPES OF TEETH Neck ○ Between the crown and root ○ Portion surrounded by the gingivae Root ○ Fixed in the root socket surrounded by the periodontium or the connective tissues surrounding the roots ○ Number of roots varies on the type of tooth: Canine: 1 root Bicuspids/Premolars: 2 roots Tricuspids/Molars: 3 or more roots Dentine ○ Covered by enamel over the crown Cement [Moore] ○ Covers the root Figure 15. Teeth Regions Pulp Cavity Incisors: have cutting edges for tearing ○ Contains the connective tissue, blood vessels, and Canine: single prominent cones for piercing nerves, which pass through the apical foramen (root Premolars or bicuspids: have two cusps (can be seen from foramen) the root) ○ During root canal, pulp cavity is emptied of its contents, Molars: have three or more cusps for crushing removing the connective tissue together with its Eight kinds of permanent teeth (from midline to most lateral neurovascular structures portion): NEUROVASCULATURE OF THE TEETH ○ Central incisor ○ Lateral incisor Superior and inferior labial arteries ○ Canine ○ 1st Premolar 💬 ○ Branches of the facial artery Lymphatic drainage and alveolar veins have the same name as the arteries ○ 2nd Premolar ○ 1st Molar Superior alveolar arteries and veins ○ 2nd Molar ○ Supply/drains the maxillary teeth ○ 3rd Molar (wisdom teeth) Inferior alveolar arteries and veins ○ Supply/drains the mandibular teeth 💬 Erupts at age 18-25 Incisors and canines are sometimes referred to as “labial” while premolars and molars are sometimes referred to as Lymphatic vessels ○ drains into the submandibular lymph nodes “buccal” Innervation ○ Dental Plexuses Branches of superior (CN V2) and inferior (CN V3) alveolar nerves Supplies maxillary and mandibular teeth Figure 16. Inferior view of maxillary teeth (left) and Superior view of mandibular teeth (right)[PPT] ANATOMY Upper GIT - Foregut PAGE 4 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD D. PALATE SOFT PALATE Figure 18. Median section of head and neck[Moore] Figure 21. Muscles of soft palate[Moore] Forms the arched roof of the mouth and the floor of the nasal Movable structure forming the posterior ⅓ of the palate cavities Suspended from the border of the hard palate Separates the oral cavity from the nasal cavity and the No bony skeleton nasopharynx (superior to the palate) Posteroinferiorly, the soft palate has a curve free margin from Superior/Nasal surface: covered by respiratory mucosa where hands the muscular uvula Inferior surface: covered by oral mucosa Continuous with the walls of the pharynx laterally Cleft palate: failure of fusion of the intermaxillary bones The palatine aponeurosis attaches to the free edge of the HARD PALATE hard palate It is joined to the tongue and the pharynx by the palatoglossal and palatopharyngeal arches Contains a few taste buds at its oral surface VASCULATURE AND INNERVATION OF PALATE Figure 19. Inferior view of hard palate[Moore] Concave structure with its space mostly filled by the tongue at rest Anterior ⅔ of the palate forming the bony skeleton, Figure 22. Nerves and Vessels of the palate[Moore] formed by the palatine process of the maxilla and the horizontal plates of the palatine bones Palate has a rich blood supply Greater palatine artery OPENINGS OF THE HARD PALATE ○ Branch of descending palatine artery Incisive fossa Lesser palatine artery ○ Depression at the midline of the bony palate at the back ○ Smaller branch of descending palatine artery that enters 💬 of the central incisor teeth where the incisive canals open the palate to the lesser palatine foramen ○ Incisive canals Veins of the palate are tributaries of the pterygoid venous ○ Where the nasopalatine nerve passes from the nose plexuses 💬 Greater palatine foramen Sensory nerves are branches of Maxillary nerve ○ Located medial to the 3rd molar Palatine nerves accompanies the arteries of the greater ❗️ ○ Pierces the lateral border of the bony palate and lesser palatine foramina ○ Significance: neurovascular provisions of the palate Tensor Veli Palatini: supplied by V3, the rest are V2 ○ Where greater palatine vessels and nerves emerge from this foramen and run anteriorly to the palate Table 2. Innervation of Palate Lesser palatine foramen Nerve Structure ○ Posterior to the greater palatine foramen Greater palatine nerve Gingivae, mucus membrane, ○ Pierces the pyramidal process of the palatine bone glands of most of the hard palate ○ Significance: transmits the lesser palatine vessels and Nasopalatine nerve Mucus membrane of the anterior nerves to the soft palate and adjacent structure part of the hard palate Lesser palatine nerve Soft palate Figure 20. Nerves and vessels of palate[Moore] ANATOMY Upper GIT - Foregut PAGE 5 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD F. TONGUE PARTS OF THE TONGUE Underside of the tongue / inferior tongue ○ Movable, no lingual papillae ○ Covered by a transparent mucous membrane Frenulum ○ Allows anterior part of the tongue to freely move MUSCLES OF THE TONGUE Figure 23. Parts of the tongue[PPT] Root ○ Attached between the mandible, hyoid and vertical posterior surface of the tongue Body ○ ⅔ of the tongue Apex (tip of the tongue) ○ Anterior end of the body that rests on the incisors The body and the tip of the tongue are extremely mobile Figure 26. Muscles of the tongue[Moore] while the root does not move There are two opposing forces by the muscles that allows the SURFACES OF THE TONGUE tongue to stick out at the midline (like genioglossus supplied by hypoglossal nerve) See Figure 52 in the Appendix for Muscles of the Tongue INNERVATION OF TONGUE Figure 24. Top surface of the tongue[PPT] Top of the tongue (Dorsum of tongue) ○ Terminal Sulcus ○ V shaped groove which divides the tongue to anterior and posterior surfaces of the tongue ○ The angle which points posteriorly is the Foramen Cecum A small pit that is a remnant of the embryonic thyroglossal duct from which the hyoid gland developed Figure 27. Nerve supply of the tongue[Moore] ❗️ ○ Can be located because of the lining of papilla called Vallate papilla All muscles of the tongue EXCEPT the Midline groove PALATOGLOSSUS receive motor innervation from CN XII ○ Divides the tongue into left and right parts Anterior 2/3 ○ Touch and Temperature - Lingual nerve (V3) ○ Taste (except for vallate papillae) - chorda tympani nerve (VII) Posterior ⅓ ○ Mucosa of the posterior 1.3 and vallate papillae is supplied by the lingual branch of the Glossopharyngeal Nerve (IX) for both general sensation and taste 4 basic taste sensations ○ Sweet (Apex), Salty (Lateral Margin), Sour & Bitter (Posterior) ○ All other tastes aside from 4 are not actual tastes, they come from olfactory sense. Figure 25. Inferior surface of the tongue[PPT] ANATOMY Upper GIT - Foregut PAGE 6 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD VASCULATURE OF TONGUE Figure 28. Vasculature of Tongue[PPT] Arteries are derived from lingual artery which arise from Figure 30.Oral cavity proper[PPT] external carotid artery G. SALIVARY GLANDS ○ Dorsal lingual arteries Supply root of the tongue ○ Deep lingual arteries Supply tip of the tongue ○ Arteries separated by lingual septum Are always a pair Veins of the tongue ○ Dorsal lingual veins that accompanies the lingual arteries LYMPHATIC DRAINAGE OF TONGUE Figure 31. Salivary glands[Moore] Submandibular gland ○ Submandibular/Wharton’s duct Sublingual gland ○ Rivinus duct Parotid gland ○ Stensen’s duct Function of Saliva Figure 29. Lymphatic drainage of the tongue[Moore] ○ Keeps the mucous membrane moist ○ Lubricates food during mastication Superior deep cervical lymph nodes ○ Begins digestion of starches ○ Drains bilaterally from root of the tongue ○ Serves as an intrinsic mouthwash Inferior deep cervical lymph nodes ○ Plays a significant role in prevention of tooth decay and in ○ From medial part of the body of the tongue the ability to taste Submandibular lymph nodes ○ From right and left parts of the body of the tongue E. CLINICAL CORRELATION: ORAL CAVITY Submental lymph nodes CLEFT LIP ○ From tip/apex of the tongue 📖 All lymph from the tongue drains to the deep cervical nodes and passes via the jugular venous trunk. Figure 32. Cleft lip[PPT] Caused by a failure in development on the 4th-8th week of life, AOG (when the face is developing) Highly correctable with surgery ANATOMY Upper GIT - Foregut PAGE 7 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD CLEFT PALATE It is also aided by gravity Muscular tube 25 cm long with 2 cm average diameter 3 constrictions (where potential foreign body may lodge) ○ Cervical constriction ○ Thoracic/ Broncho-aortic constriction ○ Diaphragmatic constriction Follows the curve of the vertebral column as it descends down the neck and the mediastinum It has internal circular and external longitudinal muscles ○ Proximal ⅓ of the external layer - voluntary striated muscles ○ Distal ⅓ of the external layer - smooth muscles ○ Middle ⅓ of external layer - both smooth and striated General direction: vertical but will have 2 slight curves Figure 33. Cleft Palate[SYNCH] through its course Caused by a failure of the intermaxillary suture and ○ Starts at the midline → inclines to the left (at the root of interpalatine suture to fuse the neck level) → passes through the midline again(at Highly correctable with surgery T5 level) → deviates to the left as it passes forward to the esophageal hiatus and diaphragm CYANOSIS OF THE LIPS ○ Important when accessing the esophagus for drainage in cases of trachea-esophageal fistula (TEF) You should drain at the left side of the neck Encircled by the esophageal plexus distally ○ Formed by the vagal trunks and thoracic sympathetic trunks via the greater splanchnic nerves Flares distally into a trumpet shape as it enters the cardiac orifice of the stomach Figure 34. Cyanosis of the lips[PPT] A. ESOPHAGEAL CONSTRICTIONS May be physiologic Important in reviewing radiographs and evaluation of ○ Lips generally have abundant superficial arteriole supply dysphagia that constrict during cold ○ Dysphagia: difficulty in swallowing ○ Purplish cold is caused by deficiency of oxygen Can be visualized through barium swallow test May also be pathologic, as in heart conditions ○ Special type of imaging test that uses barium and xrays SUPERNUMERARY TEETH to create images of your upper GI tract Figure 35. Supernumerary teeth[PPT] Existence excessive number of teeth in relation to the normal dental formula Common orthodontic problem Easily be corrected by extraction or braces Associated with other symptoms II. ESOPHAGUS Figure 37. Esophageal constrictions under the barium swallow test [Moore] 1. Cervical Constriction At the upper esophageal sphincter at the pharyngo-esophageal junction 15 cm from the incisors Caused by cricopharyngeus muscles 2. Thoracic/ Broncho-aortic Constrictions 2 constrictors 1st constrictor → 22.5 cm from the incisors → Caused by the arch of the aorta Figure 36. Esophagus and its relationships [Moore] 2nd constrictor Function: conveys food from the pharynx to the stomach → 27.5 cm from the incisors Food passes rapidly due to the peristaltic action of its → Caused by the left main bronchus musculature ANATOMY Upper GIT - Foregut PAGE 8 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD 3. Diaphragmatic Constriction 5th thoracic vertebrae. Finally, deviates to the left as it Passes through the esophageal hiatus of the diaphragm 40 cm from the incisors, at the level of T10 💬 passes down the esophageal hiatus For newborns, when esophagus is not yet patent, deviation is created on the left side of the neck – B. RELATED STRUCTURES TO THE ESOPHAGUS Phrenico-esophageal ligament ○ Permits independent movement of the diaphragm and 💬 esophagostomy Esophageal plexus: formed by vagal trunks and thoracic sympathetic trunks esophagus during respiration and swallowing Esophagogastric junction ○ AKA gastroesophageal junction ○ Right border of the abdominal esophagus ○ Gastroesophageal sphincter: lies to the left side of the T11 vertebra as it enters the stomach ○ Z line: line where the mucosa abruptly changes into gastric mucosa From non-keratinized stratified squamous epithelium to simple columnar epithelium with goblet cells (mucus secreting type) Jagged line Esophageal hiatus ○ Functions as physiologic inferior esophageal sphincter (contracts and relaxes) Figure 40. Abdominal portion of the esophagus 💬 Lies in the esophageal groove on the posterior surface of the left lobe of the liver C. VASCULATURE OF ESOPHAGUS ARTERIAL SUPPLY Cervical esophagus ○ Supplied by the inferior thyroid artery Each artery gives off ascending and descending branches that anastomose with each other and across the midline Thoracic esophagus ○ Supplied by the branches of thoracic aorta Figure 38. Related structures to the esophagus Bronchial arteries 💬 Use trachea as the landmark. Palpate the spine of the Esophageal arteries Abdominal esophagus 💬 cervical vertebra to locate the muscular esophagus Esophagus inclines more to the left side of the neck. It is below the trachea and above the spine ○ Supplied by the ascending branches of: Left phrenic arteries Left gastric arteries VENOUS DRAINAGE Venous blood from the esophagus drains into the submucosal plexus, and further drains to the periesophageal venous plexus Esophageal veins arise from this plexus and drain in a segmental way similar to the arterial supply Cervical esophagus ○ Drains into the inferior thyroid vein Thoracic esophagus ○ Drains into the azygos and hemiazygos veins (to the SVC), intercostals, and bronchial veins Abdominal esophagus ○ Drains into the left gastric vein (tributary of the portal venous system) In cases of portal hypertension or liver disease, there is dilatation of these esophageal veins that may cause them to bleed INNERVATION Cervical esophagus ○ Upper half: somatic motor and sensory Figure 39. Relationship of thoracic aorta and esophagus ○ Lower half: parasympathetic (vagal), sympathetic, and 💬 💬 Esophagus anterior to the thoracic aorta General direction of the esophagus is vertical, but it visceral sensory Receives somatic fibers via branches from the recurrent laryngeal nerves and vasomotor fibers from presents as two slight curvatures. First curvature starts at the the cervical sympathetic trunks through the plexus midline then it inclines to the left side up to the root of the around the inferior thyroid artery neck. Then, it passes to the midline again at the level of the ANATOMY Upper GIT - Foregut PAGE 9 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD Thoracic esophagus A. PARTS OF THE STOMACH ○ Right and left vagus nerves Left vagus nerve Travels down anteriorly and laterally Right vagus nerve Travels down posteriorly ○ Left recurrent laryngeal nerve Abdominal esophagus Esophageal plexus, formed by the vagal trunks and the thoracic sympathetic trunks via the greater splanchnic nerves and periarterial plexuses around the left gastric and inferior phrenic arteries MNEMONICS LARP: Left Anterior, Right Posterior → Left Vagus Nerve travels Laterally and Anteriorly → Right Vagus Nerve travels Posteriorly Figure 42. Parts of stomach [Moore] Also applies to the stomach 1. Cardia Receives terminal portion of the esophagus E. CLINICAL CORRELATION: ESOPHAGUS 2. Fundus ESOPHAGEAL VARICES Dilated superior part 3. Body Major part of the stomach between the fundus and the pyloric antrum 4. Pyloric part Funnel-shaped region Pyloric Antrum → Leads into the pyloric canal Pyloric Sphincter → Leads to the duodenum → Aids as a gatekeeper Figure 41. Esophageal varices Because of submucosal veins of the inferior esophagus draining to both the portal and systemic venous system ○ They constitute a portal systemic anastomosis In portal hypertension, blood is unable to pass through the liver through the hepatic portal vein ○ Causing reversal of flow in the esophageal tributaries Large volume of blood causes the submucosal veins to Figure 43. Anterior Stomach enlarge, forming the esophageal varices ○ Because of failure to drain in the portal system 💬 Gastric canal: located along lesser curvature at the III. STOMACH Expanded part of the digestive tract between the esophagus and the small intestine 💬 Gastric folds: longitudinal surface interior of stomach B. CURVATURES OF THE STOMACH Functions: Lesser Curvature ○ Accumulates ingested food ○ Shorter concave at right border of the stomach ○ Food blender ○ Angular notch ○ Reservoir Most inferior part that lies to the left of the midline ○ Chief function: Enzymatic digestion Indicates the junction of the body and pyloric part Larger in diameter than intestine, capable of accumulating Greater Curvature 2-3L of food ○ Longer convex at the left border of the stomach Chyme ○ Gastric juices convert masses of food into a semiliquid mixture called chyme which passes into the duodenum ANATOMY Upper GIT - Foregut PAGE 10 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD C. POSITION OF THE STOMACH Gastric canal/groove ○ Forms temporarily and longitudinally during swallowing along the lesser curvature ○ Observed endoscopically Muscular pylorus ○ Thickened portion at the most distal part of the stomach ○ Leads to the pyloric canal and into the duodenum Figure 44. Common position of stomach in a person of medium build in supine position [Moore] Figure 48. Mucosa of the Stomach Part of the stomach is within the thoracic cage F. RELATIONS OF THE STOMACH D. VARIATIONS OF STOMACH SHAPE Borders ○ Anterior: Diaphragm, left lobe of the liver, and anterior abdominal wall ○ Posterior: Omental bursa and pancreas ○ Inferolaterally: Transverse colon along the greater curvature of the stomach and to the left colic flexure Stomach bed ○ On which the stomach rests in the supine position ○ Formed by structures of the posterior wall of omental bursa (superior to inferior): Left dome of the diaphragm Spleen Left kidney and suprarenal gland Splenic artery Pancreas Figure 45. Variations of stomach shape [Moore] Transverse mesocolon Size, shape, position of stomach varies on your eating habits ○ Wide and fat: More superiorly located ○ Long and slim: More inferiorly located, almost to the pelvis E. INTERIOR STOMACH Figure 46. Interior stomach (pathologic) Figure 49. Stomach bed Stomach is muscular, so it contracts Gastric folds/Gastric Rugae 💬 If you cut the greater omentum and release the stomach from its attachment to transverse colon, you will be able to ○ Longitudinal ridges or wrinkles ○ Found along the pyloric part along the greater curvature ○ More prominent when stomach is contracted 💬 locate the anterior and posterior portion of the stomach If you have ulcerations in the posterior portion of the stomach, you know how catastrophic it is since you have Diminishes as the stomach is distended (filled) blood vessels, it will bleed easily G. VASCULATURE OF STOMACH ARTERIAL SUPPLY From the celiac trunk of the abdominal aorta Most blood is supplied by anastomosis along the: ○ Lesser curvature by the right and left gastric arteries ○ Greater curvature by the right and left gastro-omental arteries (gastroepiploic arteries) ○ The fundus and the upper body of the stomach are supplied by the short and posterior gastric arteries Figure 47. Gastric canal [PPT] ANATOMY Upper GIT - Foregut PAGE 11 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD BRANCHES OF THE CELIAC TRUNK Posterior surface of the esophagus, to the lesser Left gastric artery curvature of the stomach ○ Towards the lesser curvature Anterior and posterior surfaces of the stomach Splenic artery T6 - T9 segments of the spinal cord ○ Towards the fundus and the spleen ○ Sympathetic innervation ○ Short gastric artery H. PYLORIC SPHINCTER ○ Left gastro-omental artery Relax with antral peristalsis Common hepatic artery Contracts as a response to endogenous duodenal stimuli ○ Towards the liver Alters retrograde movement of duodenal contents ○ Hepatic artery proper The human pylorus is a true physiological sphincter Right gastric artery ○ Characterized by a high pressure zone that will lax with Right and left hepatic artery antral peristalsis ○ Gastroduodenal artery Superior pancreaticoduodenal artery I. CLINICAL CORRELATION: STOMACH Right gastro-omental artery GASTRIC ULCER ○ Supraduodenal artery Open lesions on the mucosa of the stomach Peptic lesions ○ Lesions on the mucosa of the pyloric canal; more often found in the duodenum ○ Helicobacter pylori ○ Cause most infections of the duodenum and the stomach ○ Symptoms Burning stomach pain Fullness or bloating Fatty food intolerance Heartburn Nausea 💬 Foregut isFigure 50. Anterior celiac trunk innervated by the branches of the celiac trunk VENOUS DRAINAGE Figure 51. Gastric Ulcer[PPT] Gastric veins parallel the arteries REVIEW QUESTIONS Right and left gastric veins drain into the hepatic portal 1. What is the innervation of the upper lip? vein a. Infraorbital nerves Short gastric and left gastro-omental vein drains into the b. Superior labial branches of maxillary n. splenic vein c. Both ○ Which joins with the superior mesenteric vein to form the 2. What is the blood supply of the lower lip? hepatic portal vein a. Inferior labial branch of facial and mental artery Right gastro-omental vein drains into the superior b. Inferior alveolar arteries mesenteric vein 3. What is the innervation of the lower lip? Prepyloric vein a. Mental nerve ○ Used as a landmark in identifying the pylorus during b. Mandibular nerve surgery 4. What is the gingiva adjacent to the tongue? To drain excessive hydrochloride, speed up gastric a. Tongue lingual gingiva emptying b. Maxillary gingiva LYMPHATIC DRAINAGE 5. What is the gingiva adjacent to the cheeks and lips? Gastric lymphatic vessels accompany arteries along the a. Tongue lingual gingiva lesser and greater curvature of the stomach b. Buccal Maxillary gingiva Gastric and Gastro-omental lymph nodes c. Buccal Mandibular gingiva ○ Drains anterior and posterior surfaces towards the d. Both B and C curvatures 6. What is the nerve supply for the alveolar area, gingiva, Celiac lymph nodes alveolar bone? ○ Efferent vessels course together the large arteries to the a. Superior alveolar nerves celiac lymph nodes b. Glossopharyngeal nerve 7. What is the nerve supply for the area of mental NERVE SUPPLY prominence? Vagus nerves a. Mental branch of Maxillary nerve ○ Parasympathetic innervation b. Infraorbital nerve ○ Anterior vagal trunk 8. What divides the tongue into its anterior and posterior Left vagus nerve surfaces? Anterior to the esophagus, to the lesser curvature of a. Midline groove the stomach b. Terminal Sulcus Distributed to the hepatic and duodenal branches 9. What is the level of esophageal hiatus? ○ Posterior vagal trunk a. T8 Right vagus nerve b. T10 c. T12 ANATOMY Upper GIT - Foregut PAGE 12 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD 10. What is the blood supply of the cervical portion of the esophagus? a. Inferior thyroid artery b. Thoracic aorta c. Phrenic artery 11. What is the blood supply of the thoracic portion of the esophagus? a. Thoracic aorta b. Inferior thyroid artery c. Phrenic artery 12. What is the blood supply of the abdominal portion of the esophagus a. left phrenic artery b. left gastric artery c. Both 13. The cervical esophagus drains into the a. Inferior thyroid vein b. Superior thyroid vein 14. The abdominal portion of esophagus drains into the a. Left gastric vein b. Right gastric vein 15. What muscle of the tongue is NOT innervated by CN XII a. Hyoglossus b. Palatoglossus Answers: 1) C 2) A 3) A 4) A 5) D 6) A 7) A 8) B 9) B 10) A 11) A 12) C 13) A 14) A 15) B V. REFERENCES 2025 Trans 2026 Trans Asynchronous and Synchronous Lecture of Dr. Paculan Asynchronous Recording: ANATOMY Upper GIT - Foregut PAGE 13 of 14 ANATOMY | LE 1 Upper GIT - Foregut | Ma. Jenina Angela Esguerra-Paculan, MD VI. APPENDIX Figure 52. Muscles of the Tongue ANATOMY Upper GIT - Foregut PAGE 14 of 14