Summarise the major structures of the oral cavity, teeth, tongue and salivary glands oral cavity teeth surface anatomy of the teeth tongue

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1 Anatomy Anatomy of the upper GI tract Summarise the major structures of the oral cavity, teeth, tongue and salivary glands The oral cavity is anteriorly bordered by the oral orifice, which is surrounded by the lips. The lips have no sebaceous glands, sweat glands or hair, and are made of the following features: cupids bow, vermillion border, oral commissures, and philtrum. The lateral walls of the mouth are formed by the checks and the superior walls are formed by the hard palate and soft palate. The posterior border of the oral cavity is formed by the fauces (palatoglossal and palatopharyngeal arch) and the oropharynx. The oral cavity consists of two regions: the vestibule (between the lips/cheeks and teeth/gingivae) and the oral cavity proper (enclosed by the teeth). The teeth are different between children and adults. Children have deciduous teeth, also known as primary dentition. There are 20 deciduous teeth (4x central incisor, 4x lateral incisor, 4x cuspid or canine, 4x first molar, 4x second molar). These erupt from 6 months (central incisor) to 32 months (second molar). Adults have permanent teeth, also known as secondary dentition. There are 32 permanent teeth (4x central incisor, 4x lateral incisor, 4x canine, 4x 1 st premolar, 4x 2 nd premolar, 4x 1 st molar, 4x 2 nd molar, 4x 3 rd molar). These typically appear from the age of 6 years (1 st molar, central incisor) to 21 years (3 rd molar i.e. wisdom teeth). The surface anatomy of the teeth is in 3 parts: crown, neck and root. The crown is made of den surrounded by a layer of enamel. The neck (surrounded by gingiva) and root (within the alveolar bone) of the teeth is made of an pulp cavity which is full of pulp, alveolar vessels and nerves. The pulp is surrounded by a layer of dentin, which is then surrounded by a layer of cementum. The cementum is attached to the alveolar bone by periodontal ligaments, forming the gomphosis/dental-alveolar joint, which is a peg and socket joint. The root canal is the extension of the pulp from the neck to the apical foramen, where the blood vessels and nerves pass to enter the pulp cavity. The tongue has its root attached posteriorly to the mandible and hyoid. Its anterior 2/3 forms the floor of the mouth and extends anteriorly as the apex which is posterior to the incisors. The anterior 2/3 (oral part) consists of filiform, fungiform and circumvallate papillae. The fungiform and circumvallate papillae contain taste buds. The circumvallate papillae form a v shape at the border of the anterior 2/3 and posterior 1/3 of the tongue, which is known as the sulcus terminalis. The posterior 1/3 (pharyngeal part) of the tongue consists of lingual tonsils. The tongue is made of intrinsic and extrinsic muscles. The intrinsic muscles are longitudinal/transverse/vertically oriented and are confined to the tongue itself (no bony attachments). They allow the tongue to alter its shape, giving precision movement. The extrinsic muscles give the tongue gross movements. Name Origin Insertion Function Genioglossus Mandible Tongue, hyoid bone Protraction Hyoglossus Hyoid bone Tongue Depression Styloglossus Styloid process of Tongue Retraction temporal bone Palatoglossus Soft palate Side of tongue Elevation

2 Summarise the division, connection and muscles of the pharynx The pharynx spans from the base of the skull to C6 and is divided into three parts: nasopharynx (from torus tubarius in nasal cavity to the salpingo pharymgeal fold), oropharynx (from salpingopharyngeal fold to epiglottis) and the laryngopharynx (from epiglottis to cricoid cartilage). The pharynx is made of two groups of striated muscles: the constrictors and longitudinals. There are 3 constrictor muscles superior, middle and inferior and these are the external layer which has the function of sequentially contracting, thus pushing the food bolus down to the oesophagus in the action of swallowing. Name Origin Attachment Action Superior constrictor (CNX pharyngeal plexus) Middle constrictor (CNX pharyngeal plexus) Inferior constrictor (CNX, pharyngeal plexus, recurrent/external Mandible, pterygomandibular ligament, pterygoid hamulus Hyoid bone, stylohyoid ligament Thyroid cartilage, cricoid cartilage Pharyngeal tubercle, Pharyngeal raphe Pharyngeal raphe Pharyngeal raphe Swallowing Swallowing Swallowing laryngeal nerve) There are 3 longitudinal muscles palatopharyngeus, salpinopharyngeus, and stylopharyngeus and these are the internal layer, which elevate the pharynx in the action of swallowing and yawning. Name Origin Attachment Action Palatopharyngeus (CNX) Salpinopharyngeus (CNX) Stylopharyngeus (CNIX) Hard palate Cartilage of auditory tube Styloid process Muscles of pharynx Thyroid cartilage Muscles of pharynx Muscles of pharynx Thyroid cartilage Elevate pharynx Closes nasopharynx Elevate pharynx Opens auditory tube Elevate pharynx and larynx Differentiate the different parts of the oesophagus, including the muscles, blood supply, lymphatic drainage and nerve supply

3 The oesophagus is a 25cm long tube that is continuous with the pharynx and stomach and it has three constrictions. The cervical constriction is at its junction with the pharynx, 15cm from the teeth and is the upper esophageal sphincter (C6). The bronchoaortic constriction is 25cm from the teeth and is at the crossing of the aortic arch and left main bronchus. The diaphragmatic constriction is 41cm from the teeth and is the lower oesophageal sphincter. The oesophagus is made of 3 parts: cervical, thoracic and abdominal. The cervical portion is from C6 to the jugular notch and runs posteriorly to the trachea and medial to the carotid sheath. The thoracic portion is from the jugular notch to the oesophageal hiatus, and runs posteriorly to the heart (LA) and aorta and anteriorly to the vertebral column. The abdominal portion is inferior to the diaphragm. The musculature, blood supply and drainage of the oesophagus is divided into thirds. Third Muscles Arterial supply Venous Lymphatic drainage drainage Upper Striated Subclavian artery -> thyrocervical trunk - > inferior thyroid arteries Middle Striated and smooth Thoracic aorta -> oesophageal arteries Lower Smooth Abdominal aorta -> coeliac trunk -> left gastric artery Inferior thyroid veins -> brachiocephalic veins -> SVC Oesophageal veins -> azygos vein -> SVC Left gastric vein -> portal vein Deep cervical nodes Superior and posterior mediastinal nodes Left gastric nodes Coeliac nodes The nerve supply of the oesophagus is divided into halves Half Nerve supply Type of innervation Upper Recurrent laryngeal nerve Somatic motor (from CNX) Lower CNX Sympathetic ganglia Enteric Parasympathetic Sympathetic Describe the stomach and the major parts, blood supply, lymphatic drainage and nerve supply The stomach has four major parts, these being the cardia (just after the oesophagus), the fundus (the anterior protruding portion), the body (makes up most of the mass), and the pyloric region (the antrum and canal which head into the duodenum). It has two borders: lesser curvature (more superior) and greater curvature (more inferior), which both have omenta attached to them. The omenta are part of the peritoneum. The stomach is innervated by branches of the celiac trunk. The celiac trunk branches into the left gastric artery, splenic artery (left gastroepiploic, short gastric), and common hepatic artery (right gastric, gastroduodenal -> right gastroepiploic). Artery Course Supplies Left gastric Coeliac trunk -> left gastric Superior part of lesser curvature, cardia

4 Right gastric Left gastro-epiploic Right gastro-epiploic Short gastric Gastroduodenal hepatic artery -> right gastric Coeliac trunk -> splenic artery -> left gastro-epiploic artery hepatic artery -> gastroduodenal artery -> right gastro-epiploic artery Coeliac trunk -> splenic artery -> short gastric hepatic artery -> gastroduodenal artery Inferior part of lesser curvature, cardia Greater omentum (superiorly) Greater curvature Greater omentum (inferiorly) Greater curvature Upper portion of greater curvature Fundus Pylorus The veins of the stomach are as follows: left gastro-epiploic vein, short gastric vein, left gastric vein, IMV -> splenic vein -> portal vein; right gastric vein -> portal vein; right gastroepiploic vein -> pancreaticoduodenal vein -> SMV -> portal vein. The stomach is innervated by the anterior and posterior vagal trunks (parasympathetic), thoracic splanchnic nerves, celiac ganglion and plexus, sympathetic trunk and ganglia (lumbar portion), lumbar splanchnic nerves, and the superior mesenteric ganglion and plexus. The lymphatic drainage of the stomach is to the splenic nodes, gastro-epiploic nodes, gastric nodes, and pyloric nodes. Describe the different parts of the duodenum and pancreas, and their blood supply and lymphatic drainage The duodenum and pancreas are both retroperitoneal organs, which means that they are situated posterior to the peritoneum in the space between the parietal peritoneum and the erector spinae muscles and vertebral column. The duodenum is a C shaped tube which has 4 parts. The superior part (bulb of duodenum), descending part (has the greater and lesser duodenal papilla), horizontal part, and the ascending part (duojejunal flexure, suspensory ligmant of duodenum, also known as the ligament of Treitz). The inside of the tube is lined by plicae circulares, which are circular folds in the mucosa. The pancreas is situated adjacent to the curvature of the duodenum and has 4 parts: uncinated process (next to ascending part of duodenum), head (next to the horizontal part of the duodenum), neck (next to the descending part of the duodenum), body and tail. The duodenum and pancreas are supplied by branches of the coeliac trunk and the superior mesenteric artery. Artery Source Supplies Superior anterior pancreatico-duodenal artery hepatic artery -> gastroduodenal artery -> superior anterior pancreatico-duodenal artery Head of pancreas (drains into SMV) Upper half of duodenum

5 Superior posterior pancreatico-duodenal artery Inferior pancreaticoduodenal Pancreatic hepatic artery -> gastroduodenal artery -> superior posterior pancreaticoduodenal artery Superior mesenteric artery - > inferior pancreaticoduodenal artery Coeliac trunk -> splenic artery -> pancreatic artery Lymphatic drainage is through the pancreatico-duodenal nodes. Head of pancreas (drains into SMV) Upper half of duodenum Head of pancreas (drains into SMV) Lower half of duodenum Neck, body and tail of pancreas (then drains into splenic vein) Surface anatomy of the abdomen 9/2/16 Understand the boundaries of the abdominal cavity Superiorly, the abdomen is boarded by the diaphragm. Posteriorly, it is bordered by the lumbar vertebrae, quadratus lumborum, and transverse abdominis. Anterolaterally, it is bordered by the muscles of the abdominal wall: transversus abdominis, internal and external abdominal obliques. Inferiorly, it is bordered by the pelvic brim: left and right coxal bones. Be able to locate surface landmarks of the abdomen The following is the list of surface landmarks on the abdomen:

6 Also useful is: linea semilunaris, iliac crest, iliac tubercle, pubic symphysis, superficial inguinal ring Know the planes that create the four quadrants and nine regions The four quadrants of the abdomen are made by the median plane and the transumbilical plane. There are two longitudinal and two transverse planes that create the nine regions of the abdomen. The two longitudinal planes are the left and right midclavicular planes. The two transverse planes are the subcostal and transtubercular planes List the structures at the transpyloric plane. What vertebral level is this? The transpyloric plane is halfway between the jugular notch (T2/T3) and the top of the pubic symphysis. This corresponds to vertebral level L1. The structures it contains can be remembered using the mnemonic Grandparents Like Paediatric Doctors Preventing Kids Sickness. Sick Newborns Often Rank #One. Gall bladder fundus Liver Pylorus of stomach Duodenal bulb and duodenojejunal flexure Pancreas neck Kidneys hila Spleen Spinal cord end Ninth costal cartilage Original of superior mesenteric artery Root of transverse mesocolon Origin of portal vein Know the four quadrants of the abdomen and their contents Right upper quadrant Left upper quadrant Liver Tip of medial liver lobe Duodenum Spleen Pancreas Stomach Pylorus of stomach Left kidney Right kidney Pancreas Hepatic flexure Splenic flexure Parts of ascending and transverse Parts of transverse and descending colons colons Right lower quadrant Appendix Caecum Ascending colon Bladder Right ovary Uterus (if enlarged) Right spermatic cord Right ureter Left lower quadrant Sigmoid colon Descending colon Bladder Left ovary Uterus Left spermatic cord Left ureter

7 Know the nine regions of the abdomen and their contents Right hypochondriac region Epigastric region Liver Stomach Gall bladder Liver Right kidney Pancreas Small intestine Duodenum Spleen Adrenal glands Left hypochondriac region Spleen Colon Left kidney Pancreas Right lumbar region Gall bladder Liver Ascending colon Umbilical region Umbilicus Jejunum Ileum Duodenum Left lumbar region Descending colon Left kidney Right iliac region Appendix Caecum Hypogastric region Urinary bladder Sigmoid colon Female reproductive organs Left iliac region Descending colon Sigmoid colon Know the clinical relevance of important surface markings Organ Surface markings Diaphragm - dome Right 4 th intercostal space Left 5 th intercostal space Periphery Costal margin to 12 th ribs Anterior Xiphoid process Liver upper border Under diaphragm Liver right edge 4 th intercostal at mid-clavicular line Liver left edge Epigastrium Gall bladder - fundus Transpyloric plane (L1) at semilunaris Pancreas - neck Transpyloric plane (L1) at the midline Pancreas - head L1-3, to the right of the midline Pancreas body and tail L and upward to hilum of spleen Spleen 5cm to the left, 9-11 th ribs posteriorly (behind mid-axillary line) Kidney - hila Transpyloric plane (L1), 4 finger breadths from the midline Kidney upper half Sits under th ribs

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