MEDI7112Week2MouthtoStomachANATPrac2015.pdf

THE UNIVERSITY OF QUEENSLAND Faculty of Medicine & Biomedical Sciences (M+BS)

School of Biomedical Sciences (SBMS) Anatomy & Developmental Biology

2015

MEDI7112 Anatomy Practical Session Clinical Science 2 (Week 2)

Anatomy of Mouth to Stomach

Prepared by Dr Peter Wragg

in collaboration with Dr Vaughan Kippers & Dr Yacoob Omar (Updated Tuesday, 30th June, 2015)

There are a couple of ways in which you may find it useful to use these notes:

(a) Use them for your pre-lab prep, then perhaps prepare a checklist of the things YOU want to clarify and identify in the lab

(b) For those whose preferred learning methods dont involve pre-lab prep, bring the notes to the lab and work through them, preferably in a group, and using your resources as well as the specimens to work through the sections of the notes learning as you go.

Outline of this session: In todays prac, we will be looking at the details of the mouth, including the skeleton (maxilla, mandible, palatine bones), the tongue, salivary glands, palate, & floor of the mouth. We will then revise the pharynx, and see how it progresses down to become the oesophagus. We will look at the oesophagus in the thorax, and its relations to structures such as the aorta, thoracic duct, etc. We will then examine the oesophageal hiatus in the diaphragm in some detail, including its clinical relevance, before concentrating on the stomach itself. The stomach will be examined in detail, including its parts, blood supply, and innervation. We will end this weeks prac at the gastric outlet, the pylorus. Reading: Morton et al p240-244, 258-269, 294-299, 70/1, 98/9, 102/3, 108/9 Hankin et al p80-87

MEDI7112 Anatomy Prac Anatomy of Mouth to Stomach

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1. What do I REALLY need to know? Face, Mouth, and Mandible

To start this prac, find a specimen or model of a skull, and revise/study the following points.

On your specimens, identify the following bones, and note whether they are single or paired:

o Zygoma (zygomatic bone)

o Maxilla.

On the maxilla, note the two processes frontal and zygomatic which join with the bones of those names.

Note also that the maxilla has a palatine process that extends horizontally to meet its fellow of the opposite side, to form the greater part of the skeleton of the hard palate.

The alveolar process is actually the rim of the maxilla that carries the teeth of the upper jaw

Note that the main body of the maxilla is hollow the maxillary sinus.

Note also the infraorbital foramen just below the orbital rim this carries the infraorbital nerve and artery.


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Now turn your skulls over, so youre looking from below and behind. Note that the bony palate consists of the palatine processes of the maxillae, as seen above, but that posteriorly, and adjoining these, are the two horizontal plates of the palatine bones. These meet in the midline, as well as joining with the palatine processes of the maxillae, and it is these four components that together make up the skeleton of the hard palate.

Finally, check the mandible that you should have with your specimen/ model. Identify the following parts and features:

o Body of the mandible.

o Ramus of the mandible.

o Angle of the mandible.

o Mandibular notch.

o Condylar process, including the head and neck of the mandible.

o Coronoid process.

o Mandibular foramen on the medial aspect (the inside) of the ramus, guarded by a small tongue of bone, the lingula of the mandible.

o The mylohyoid line a roughened, slightly raised ridge on the inside of the body of the mandible. The mylohyoid the main muscle of the floor of the mouth attaches here.

o The alveolar margin of the mandible the part that carries the teeth of the lower jaw.

o See if your specimen has a mental foramen, and/or a visible mental symphysis.


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Teeth

Each tooth is composed of specialized connective tissue, the pulp, covered by three calcified tissues: dentine, enamel, and cementum. They are embedded in the alveolar processes of the maxilla and mandible, and surrounded by the gums known as the gingivae.

There are 20 primary teeth in a child, and 32 secondary, or permanent, teeth in an adult.

The teeth are divided into 4 quadrants, with 8 teeth in each in the adult:

o 2 incisors.

o 1 canine.

o 2 premolars.

o 3 molars. Note that the 3rd molar may erupt or not, and is known as the wisdom tooth for reasons unknown.

The nerve supply and blood supply of the teeth is well described in Morton et al p262/3. Some of the terms may be unfamiliar to you, eg cranial nerves, as you havent studied neuroanatomy yet, but it is worth a preliminary read of the innervation, and make a note to come back to it once you have done the neuroanatomy module.


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Hyoid, Muscles of Mastication, and Tongue

The hyoid is a bone that does not articulate with any other bone directly. It sits suspended from the styloid process of the skull by ligaments, lies in the front of the neck between the mandible and the larynx at the level of C3 vertebra approximately. It is the bone frequently fractured in cases of choking or strangulation (but not always the murder-mystery books imply that if the hyoid isnt fractured, then choking or strangulation could not have occurred. This is not the case).

The hyoid has a central body, and from this a pair of greater horns and a pair of lesser horns projects. Another name for a horn is cornu. So you will see the terms greater and lesser cornu as an alternative to horn.

The hyoid has several muscles attached to it, from above, behind, and below. These are involved in the functions of the tongue, floor of the mouth, and pharynx. There are also muscles that lie anteriorly in the neck, in front of the thyroid gland and the larynx, known as the strap muscles that attach to the hyoid (except for the sternothyroid).


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Next group is the facial muscles, and while they seem to be a complex set of muscles that are responsible for the entire expressive appearance of our faces, the main ones you need to learn for this prac is the group of muscles around the mouth the orbicularis oris. (The name means around the mouth). This acts as the sphincter of the mouth, controlling the opening and closure of the lips. One other you should know is the cheek muscle, the buccinator (pronounced buxinator). This is responsible for keeping food between the teeth while chewing, among other things.

Next, we have the muscles of mastication chewing. These move the mandible. Using your atlases etc, find and identify the following:

o Temporalis.

o Masseter.

o Lateral pterygoid.

o Medial pterygoid. Note how the two pterygoid muscles interleave at their attachments to the pterygoid process, and note that the lateral pterygoid attaches to the head and neck of the mandible to pull it forward, while the medial pterygoid attaches to the medial surface of the angle of the mandible much lower down, and hence acts to elevate the mandible.


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The muscles of the mouth and tongue include the tongue itself, which has intrinsic muscles, and the extrinsic muscles that attach the tongue to the mandible, hyoid, palate, and styloid process. The intrinsic muscles change the shape of the tongue, while the extrinsic muscles change the position of the tongue. The main ones you need to know are the extrinsic muscles, including the genioglossus, the hyoglossus, the styloglossus, and the palatoglossus. If you know that the glossus bit refers to the tongue (glossi = Greek; lingua = Latin), then you can work out which muscle comes from where. The genial tubercles are the little bumps on the inside of the anterior part of the body of the mandible, so the genioglossus runs from there to the tongue. Im sure you can work out for yourselves where the other three named above are attached at the end other than the tongue attachment!

Other muscles of the mouth include those associated with the soft palate, the pharynx, the cheek (eg the buccinator seen above), and the muscle forming the floor of the mouth, the mylohyoid, which is also included in the hyoid group of muscles.

Using your atlases and specimens, check as many as possible of the muscles that are attached to the hyoid, including:

o Mylohyoid forms the floor of the mouth

o Stylohyoid from the styloid process of the temporal bone

o Hyoglossus (upwards to the tongue - seen above)


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o Geniohyoid attaches the hyoid to the genioid tubercles

o Digastric (means two bellies) check anterior and posterior bellies

o Omohyoid from the scapula, via a fascial sling on the manubrium and clavicle

o Middle constrictor of the pharynx.

o Sternohyoid one of the infrahyoid muscles, from the back of the manubrium

o Thyrohyoid another infrahyoid muscle, from the thyroid cartilage of the larynx. The infrahyoid muscles are known as the strap muscles, and also include the sternothyroid.

Pharynx

Revise the pharynx from your Upper Respiratory Tract in MEDI7111 (Week 11).

The pharynx consists of a muscular tube suspended from the base of the skull, comprising three circular muscles stacked like three plant pots into one another the constrictors. They are all open anteriorly, so theyre not complete circular muscles. Using your atlases to help, try to identify on a specimen or model the superior, middle, and inferior constrictor. Note where they attach anteriorly on either side of their openings.


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There are also three vertical muscles forming part of the pharynx see if you can find them: the stylopharyngeus, palatopharyngeus, and salpingopharyngeus (from the auditory tube).

The nerve supply to the pharynx is from the vagus and glossopharyngeal nerves (cranial nerves X and IX respectively), which form the pharyngeal plexus.

Salivary Glands

The parotid gland is a salivary gland that occupies the space between the mastoid process and external acoustic meatus behind, and the ramus of the mandible in front. It is wrapped around the posterior edge of the ramus of the mandible. It is divided into two nominal parts (superficial and deep) by the facial nerve. The parotid duct runs forward from the superficial part of the gland to pierce the buccinator and enter the oral cavity adjacent to the upper 2nd molar tooth. The gland has a tough fibrous pseudocapsule, and this is one of the reasons that swelling of the gland, trying to stretch this capsule, can be so painful eg. in mumps.


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The submandibular salivary gland lies in the submandibular region, and is folded over the posterior edge of the mylohyoid muscle, thus forming deep and superficial parts. The gland is closely related to the facial artery and vein (check in your atlases and on specimens), and the deep part of the gland lies lateral to (i.e. outside) the hyoglossus muscle. Other structures in this region to note include the lingual nerve, the hypoglossal nerve, and the submandibular duct running forward from the gland itself to enter the mouth just beside the frenulum of the tongue (the median fold that tethers the tongue to the floor of the mouth).

The sublingual gland lies above the mylohyoid, just beneath the mucous membrane of the floor of the mouth. It is the smallest of the three paired salivary glands, and opens into the mouth via multiple small ducts, directly into the floor of the mouth.


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Oesophagus

The oesophagus is the downward continuation of the pharynx, and the upper 20% of the oesophagus lies in the neck. The total length of the oesophagus is between 25 & 30cm, depending on the size of the person.

It starts behind the cricoid cartilage of the larynx, and the encircling muscle fibres here are known as the cricopharyngeus muscle. It is actually the lowermost fibres of the inferior constrictor of the pharynx, and these act as a sphincter at the top of the oesophagus. They are skeletal muscle.

Just above the cricopharyngeus, between it and the rest of the inferior constrictor proper, is a relatively weak spot, (Killians area) and it is here that you may see a diverticulum (a blow-out or outpouching) called a Zenkers diverticulum, otherwise known as a pharyngeal pouch.


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The oesophagus has an inner circular muscle layer, and an outer longitudinal muscle layer, starting just below the cricopharyngeus muscle. One interesting fact about the musculature of the oesophagus is that it is skeletal muscle at the top, and smooth muscle at the lower end, with a gradual transition from one type to the other.

The oesophagus descends into the thorax behind the trachea, and is closely related to the very thin, soft, posterior wall of the trachea. Below the tracheal bifurcation, the oesophagus is closely applied to the back of the left atrium of the heart. This is where the transducer is placed during a procedure called a transoesophageal echocardiogram, so that the ultrasonic view of the heart from behind is only looking through one wall of the oesophagus and the thin wall of the left atrium.

As the oesophagus descends through the posterior mediastinum, the descending aorta swings in behind it, so that the oesophagus is in front of the aorta. See following diagram, and also See diagram on page 71 of Morton et al.

The blood supply of the oesophagus is from several small arteries branches of the inferior thyroid arteries in the root of the neck, branches from the bronchial arteries in the chest, and usually one or two direct oesophageal branches from the descending aorta in the thorax. Also a branch of the left gastric artery supplies the lower oesophagus.

Recall that an anastomosis of the VEINS of the lower oesophagus with the left gastric vein is one of the important porto-systemic anastomoses, relevant in portal hypertension, when oesophageal varices can grow enormous and bleed profusely.


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The left and right vagus nerves approach the oesophagus from each side, and form a plexus on the surface of the oesophagus. At the level of the diaphragm, the plexus eventually merges into two vagal trunks. (See diagram on page 14 above).

o The left vagus becomes the anterior vagal trunk as it passes through the diaphragm

o The right vagus becomes the posterior vagal trunk.

o If you recall from your Embryology lecture how the stomach rotates, you will understand how the left vagus becomes anterior, and the right becomes posterior.


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The oesophagus passes through the diaphragm at about the level of thoracic vertebra 10 (T10). This aperture is the oesophageal hiatus, and is formed by looping fibres that arise from the RIGHT crus of the diaphragm, even though the hiatus itself is just to the LEFT of the midline.

The junction of the oesophagus with the stomach is known as the gastro-oesophageal (or oesophago-gastric) junction, but also by the much shorter name of the cardia.

There is no TRUE sphincteric muscle here in the oesophagus itself, but the looping fibres of the right crus of the diaphragm that form the oesophageal hiatus act as a physiological/functional sphincter to prevent gastro-oesophageal reflux.

When this hiatus is too loose, the stomach can either slide up through the hiatus (a sliding hiatus hernia) or the fundus of the stomach can roll up beside the oesophagus a para-oesophageal hiatus hernia. This latter type is potentially very dangerous, while the sliding type is more of a nuisance and can be very symptomatic due to the reflux.


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Stomach

Note that the adjective gastric refers to the stomach, specifically. It is NOT as commonly used by many members of the public - a term used to describe diarrhoea (!)

Note the general position of the stomach, and how it can vary in size and shape quite significantly from one specimen to another.

Using your texts, atlases, and other resources, and using the specimens and/or models, identify the following parts of the stomach:

o Fundus.

o Body.

o Antrum and pylorus feel the pylorus and note how much thicker it is than the stomach before it and the duodenum following it.

o Greater and lesser curvatures.

o Note that an empty stomach tends to keep much the same overall shape, but it flattens from front to back (that is, antero-posteriorly). When full, it assumes a much more globular shape, and there is usually a gas bubble of varying size in the fundus (when in the upright position).

Examine an opened stomach, and note the numerous folds in the gastric mucosa these are called rugae.


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Look for the cardiac orifice (in this context, the adjective cardiac does NOT refer to the heart it refers to the cardia, the opening into the stomach of the oesophagus). This is also called the oesophago-gastric junction.

Try and find the pyloric sphincter, and if it has been cut through on your specimen, note just how thick that circular muscle is. If it has not been cut through, try to push your fingertip through it and note how tight it can be.

Note the four main arteries supplying the stomach:

o Left gastric artery, from the coeliac trunk, supplying mainly the lesser curvature from the upper part heading down and to the right. This joins with the right gastric artery, usually from the common hepatic artery, heading back around the lesser curve from right to left. This forms an arterial arc running around the lesser curve, with branches running from it onto the stomach.

o In a very similar way, there are two gastroepiploic arteries (epiploic refers to omentum) that form an arc running around the greater curvature. The left gastroepiploic artery arises from the splenic artery near or in the hilum of the spleen, and runs down and around to the right where it joins the right gastroepiploic artery that arises from the gastroduodenal artery.

o In addition to these four main arteries, there are some smaller arteries that arise from the splenic artery near the hilum of the spleen, and run towards the right to supply mainly the fundus of the stomach. These are the short gastric arteries.


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If you have access to a specimen with an intact lesser omentum, note where it attaches to the stomach, and to the liver (this is also known as the gastrohepatic ligament).


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While the greater omentum is essentially continuous around the greater curvature of the stomach, note that if you follow it round and up towards the fundus, it attaches to the spleen this is the gastrosplenic ligament (its really just a part of the greater omentum). Recall from the video you saw in the Embryology lecture that this whole structure forms from the dorsal mesogastrium, with the spleen forming within the dorsal mesogastrium. The rest of the dorsal mesogastrium, between the spleen and the left kidney and diaphragm, is the lienorenal ligament (also known as the spleno-renal ligament. Lieno (pronounced lye-eeno) refers to the spleen).

After watching the video linked below, you should understand that surgical entry into the lesser sac is via the gastrocolic ligament, and the following picture shows this part of the greater omentum cut through, and the stomach reflected upwards to reveal the posterior abdominal wall structures, such as the pancreas.

For those who would like to watch the 4-minute video again, on the development of the foregut and the mesogastria, here is the link:

https://www.youtube.com/watch?v=s2cNCUL1r3A

Note that there are two or three versions of this video on YouTube, including one with background music(!) The version I have linked to here is the one with the better audio.


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From that video, remind yourself of the derivatives of the:

o ventral mesogastrium (lesser omentum, liver with its coronary and triangular ligaments, falciform ligament) and

o dorsal mesogastrium (greater omentum, spleen, spleno-renal ligament, etc).

Also, remind yourself why there is a free edge of the lesser omentum (its where the ventral mesogastrium finishes, at the junction of foregut and midgut), and how the lesser sac forms. The lesser sac, you will recall, lies behind the stomach, and in front of the pancreas.

In the free edge of the lesser omentum, the portal vein (posteriorly) and the bile duct and hepatic artery can be found. Now look for an opening that has these three structures in front, and the IVC, liver, right suprarenal gland, and perhaps the upper pole of the right kidney behind. This is the opening into the lesser sac of the peritoneal cavity known as the epiploic foramen (also widely known by its eponym of the foramen of Winslow), indicated by the little arrow just to the right of the red dot in the following picture. Also seen in the picture on p19 above.

In cases of severe bleeding from the liver, during abdominal surgery, there is a manoeuvre whereby a finger is placed through the epiploic foramen, and the structures in the free edge of the lesser omentum (portal vein, hepatic artery, and bile duct) are grasped between the thumb in front and the finger behind. This can control the bleeding significantly, and is known as the Pringle Manoeuvre. It is used to gain control of massive haemorrhage until a more definitive strategy can be applied, eg direct oversewing of a liver laceration, or even just a proper clamp to replace the fingers performing the manoeuvre, etc.


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In the following diagram, on the left is the Pringle Manoeuvre while on the right is a clamp replacing the finger and thumb.

In the next diagram, the Pringle Manoeuvre is being used to guide a clamp that has been inserted through an opening in the lesser omentum:

Lymphatic drainage

The stomach lymphatic drainage tends to follow its arterial supply back, as is the case generally. So a cancer of the stomach can spread to nodes in the spleen, the pancreas, greater omentum, and to the para-aortic nodes.


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There is a collection system for the lymphatic drainage of the stomach and upper small intestine, lying just below the diaphragm, called the cisterna chyli. It is named this because the fatty substances absorbed from the upper bowel form a milky-white oily fluid called chyle. This accumulates in the cisterna chyli and then the thoracic duct drains upwards from this structure, to end in the major veins at the root of the neck, draining back into the venous circulation at that point. Thus, lymph and chyle together empty back into the venous circulation eventually. So it is not hard to imagine how malignancies of the upper GI tract particularly the stomach can spread to the root of the neck and subsequently back into the venous system, and thence to anywhere.


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2. What would be useful to know in addition to the above?

In relation to the soft palate, examine a skull from below, and imagine how the soft palate hangs from the back of the bony hard palate. The control of the soft palate is vital for coordinated swallowing, the gag reflex, and speech. So how is this controlled? The soft palate consists of a sheet of fibrous aponeurosis with muscles inserted into it, and hence can be tensed and elevated. A muscle called tensor palati arises from the fossa between the pterygoid plates, and has a tendon that hooks around the pterygoid hamulus on the medial pterygoid plate, and enters the soft palate from the side. It thus pulls sideways against its opposite number, tensing the soft palate. Another muscle, the levator palati, arises from the inferior surface of the petrous temporal bone and the cartilaginous part of the auditory tube, and inserts into the palatine aponeurosis. As this muscle is pulling from more posteriorly, it elevates the free edge of the palate, as opposed to tensing it. There are two other muscles involved with this small structure, the soft palate the palatoglossus, and the palatopharyngeus. These run downwards from the lateral part of the soft palate, forming two arches on the side wall of the pharynx near the back of the tongue. It is between these two folds that the palatine tonsils lie these are masses of lymphoid tissue, and generally called simply the tonsils. But the muscles that make up the two arches are also active in closing off the oral cavity from the pharynx (by moving together with the corresponding muscles on the opposite side) and moving the soft palate down like a trapdoor.


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You can see from the above descriptions (which, believe it or not, are simplified) that the control and function of the soft palate is vital. And due to the complexity of its operation, it is one of the control mechanisms that fails in conditions such as stroke, for example.

Now look at the tongue and its muscles. As mentioned earlier, the intrinsic muscles change the SHAPE of the tongue, while the extrinsic muscles change the POSITION of the tongue. And all of these except the palatoglossus are innervated by the hypoglossal nerve (cranial nerve XII). Identify on a specimen or model the genioglossus. Note that it is attached anteriorly, to the genial tubercles on the posterior surface of the mental process of the mandible (the chin). So, given that it fans backwards and upwards into the tongue, what is its action if it contracts?

The answer to that, of course, is that it protrudes the tongue. Now, if a patient has a lesion of the hypoglossal nerve, so that the muscles of the tongue on one side are paralysed, and if you ask that patient to poke out their tongue which way would you expect the tongue to deviate? Towards the side of the lesion, or away from it? Think of the anatomy of the genioglossus to work out the answer.

Note from the following picture that the intrinsic muscles are in 3 dimensions longitudinal, transverse, and vertical.


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And just as a reminder, here are the extrinsic muscles again but you should be familiar with these by now ;)

And finally, a summary of the tongue muscles and their actions, innervation etc:


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The nerve supply of the oesophagus is worth mentioning, particularly as the muscular coat of the oesophagus (inner circular and outer longitudinal) is skeletal muscle in the upper third (so-called voluntary muscle), smooth muscle in the lower third, and mixed in the middle third. It forms a gradual transition from top to bottom. So the nerve supply is interesting.

Special motor fibres in the vagus supply the skeletal muscle in the upper oesophagus. Parasympathetic preganglionic fibres also from the vagus enter the smooth muscle in the lower part, with these fibres synapsing in the wall of the oesophagus with very short postganglionic fibres then supplying the smooth muscle.

It is worth remembering that the vagus is not JUST a parasympathetic nerve, although that is its major function. It supplies skeletal muscle (oesophagus, and you will recall that it also supplies most of the skeletal muscle of the pharynx, and larynx too). This is an example of so-called voluntary skeletal muscle acting in an involuntary way, innervated by the vagus although swallowing, speech etc can be initiated voluntarily, the actual muscle functions are largely autonomous once initiated. It is hard to stop a swallow once it is under way.

There is also sympathetic innervation of the oesophagus, both directly from the sympathetic trunk and via branches from the splanchnic nerves (all as postganglionic fibres). These are thought to act contrary to the parasympathetic fibres, causing relaxation of the oesophagus to allow bolus passage. Pain from the oesophagus is also mediated via these sympathetic connections back to the sympathetic trunks. This is the pain that is commonly referred to as heartburn as it is burning in nature and situated just behind the lower sternum, and is usually caused by acid reflux from the stomach. Heres a summary of autonomic supply to the GIT


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The stomach has a strong muscular layer arranged chiefly into an inner circular and outer longitudinal layer, although there are spiral oblique fibres interspersed with these, particularly towards the inner part of the stomach wall. Some books describe a definite innermost oblique layer, while others have the oblique fibres throughout the wall as described above, but with a predominance towards the inner (luminal) part of the wall. These layers ensure that the stomach is capable of churning and grinding food and ensuring good mixing, especially as it gets softened by gastric enzymes.

The mucosa of the empty stomach is thrown into folds called rugae, which generally run longitudinally. However, these folds are not permanent they are dynamically changing as the stomach changes its shape, due both to filling and also to the contractions of the muscle layers.

Solid food can remain semisolid or solid for several hours, before slowly becoming a smooth liquid mixture called chyme. The pylorus allows passage of liquid, but solids are retained in the stomach until digested more. Interestingly, different foods are emptied into the duodenum at different rates. Carbohydrates are the first to be emptied (after an hour or two), proteins are next, and fats are the slowest.

The lymphatic drainage of the stomach is important, as gastric tumours can occur in different parts of the stomach. The routes of drainage are important for the treating medical team to understand. They eventually drain into the cisterna chyli as described in Section 1 of these notes, and thence to the thoracic duct. But there are regional groups of nodes around the stomach, as shown in the following diagram:


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3. WHY do I need to know this?

You will be seeing patients who have cancer of the stomach and you need to understand the anatomy of the condition itself eg where is it likely to spread via either the lymph nodes or via the venous return but also the anatomy of the surgery that may need to be performed.

You will be seeing some of this anatomy from the INSIDE in your clinical rotations you will see endoscopies performed, looking down into the stomach and duodenum.

The various developmental anomalies mentioned earlier in these notes and in the lectures, such as trachea-oesophageal fistula or oesophageal atresia are particular problems in infants, and unless treated, can be incompatible with life.

Hiatus hernia is a very common problem but we dont really know why is it diet-related? Obesity? Is there any geographical difference in the incidence? (something for you to research). But it is important that you know the anatomy of the condition, and also to understand why a sliding hiatus hernia can be very symptomatic but rarely acutely dangerous, whereas a rolling (para-oesophageal) hiatus hernia has the potential for very acute life-threatening complications.

Cancer of the oesophagus is an awful condition, related to smoking (but also occurring in non-smokers). The oesophagus is lined by non-keratinising squamous epithelium, so tumours of the main part of the oesophagus tend to be squamous cell carcinomas. Tumours close to the oesophago-gastric junction (the cardia) tend to involve the glandular gastric-type epithelium and therefore are more commonly adenocarcinomas. Treatment of oesophageal cancer is an area that can be particularly demanding, and depending on the stage at which the tumour is diagnosed, the results of treatment can range from very good to very poor. Complications of treatment are common, whether the treatment is surgical, or chemo-radiation, or both. But the anatomy of the oesophagus and the applied anatomy of the surgical options to treat this devastating condition is obviously very important.

Problems involving the mouth are everyday common problems that are seen by GPs, emergency doctors, dentists, pharmacists, nurses, and a whole range of other specialties. These problems can range from fungal infections (Candidiasis, for example) that can severely impact on the ability to eat properly, problems with the teeth, problems with the tongue, palate, pharynx (eg pharyngeal pouch), all the way through to major malignant tumours involving the mandible, maxilla, tongue, lips, or even half the face. These can be a real challenge in terms of being able to work with the anatomy to provide airway, ability to drink and eat, and drain salivary secretions.

We will see more potential problems when we study the rest of the GIT.

Outline of this session:1. What do I REALLY need to know?Face, Mouth, and MandibleTeethHyoid, Muscles of Mastication, and TonguePharynxSalivary GlandsOesophagusStomachLymphatic drainage

2. What would be useful to know in addition to the above?3. WHY do I need to know this?

MEDI7112Week2MouthtoStomachANATPrac2015.pdf

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