Anatomy زكريا الحسنات + النعسان 10/111/2015

Transcription

1 3 15 Anatomy زكريا الحسنات + النعسان محمد 10/111/2015 د. م حمد ع لو ه

2 بسم هللا الرحمن الرحيم 1) pharynx: A-nasopharynx B-oropharynx C-laryngeopharynx 2) esophagus and general histology of gastrointestinal tract 3) introduction about anteriolateral abdominal wall The doctor started the lecture by announcing that in the practical lab there will be additional information, which is not explained in the theory part. 1) pharynx In the previous lecture doctor started talking about the wall of the pharynx, it consists mainly of six muscles, three main muscles (commonly known as circular/constrictors ) they are superior constrictor, middle constrictor, and inferior constrictor muscles, additional to them are other three minor vertical muscles, help in elevation of the pharynx during swallowing, these are stylopharyngeus muscle, salpingopharyngeus muscle and the most important one of the minor muscles is the palatopharyngeus muscle. These six muscles together form the wall of the pharynx. The pharynx extends from the base of the skull down to the level of C6, and divided into three main parts; Nasopharynx behind the nose at level of C1-C2, Oropharynx behind the oral cavity at level of C2-C3, and Laryngopharynx behind the larynx at level of C4-C6. A- nasopharynx The first part of pharynx, can be distinguished from nasal cavity by bony shells called concha (concha mean shells) the posterior border of concha marks the end of the nasal cavity, behind the concha you will get into nasopharynx, which is located above the soft palate.

3 2 1 3 Figure 1 In the roof of the nasopharynx there is an aggregation of lymphatic nodule, it is called the pharyngeal tonsil or adenoid tonsil(figure 1, arrow 1), and it is the largest tonsil in the human body. Down in the lateral wall there is an opening for a tube that connects the nasopharynx with the middle ear it is the auditory or Eustachian tube. At the upper border of that opening there is a small elevation, this is called tubal elevation(figure 1, arrow 2), it is formed because the medial end of the auditory tube pushing the mucosa, however another contribution to that elevation is another smaller aggregation of another lymphatic nodule around the opening, this aggregation is called the tubal tonsil, because it surrounds the opening of auditory tube in the nasopharynx. So we have two kinds of tonsils in nasopharynx; in the submucosa of the roof of the nasopharynx we have one adenoid/pharengeal tonsil, and in the right and left of the lateral walls of the nasopharynx we have two tubal tonsils in the right and left. Posteriorly and inferiorly to the opening of the auditory tube there is a fold of the mucosa, this fold contains a small bundle of muscle fibers, it is called salpingopharyngeal fold(figure 1, arrow 3), so called because it happened because of salpingopharyngeus muscle that descends from the auditory tube down and blends with palatopharyngeus muscle. Nasopharynx is lined with Pseudostratified ciliated columnar epithelium (respiratory epithelium).

4 B- oropharynx Oropharynxlocated at the level of C2-C3, is posterior to the oral cavity. Opens to the oral cavity through oropharyngeal isthmus(figure 2, arrow 1). Palatoglossal fold marks the border between oral cavity and oropharynx. The roof of oropharynx is soft palate, while the floor is posterior third of tongue, where there is a depression called vallecula(figure 2, arrow 2), located between tongue and epiglottis. In the floor of the oropharynx there is the lingual tonsil(figure 2, arrow 3). In the lateral wall of the oropharynx there is the palatine tonsil(figure 2, arrow 4), resting on the tonsillar ridge; which is marked anteriorly by palatoglossal fold, and posteriorly by palatopharyngeal fold, palatine tonsil located between these two folds and over superior constrictor muscle and sulcus terminalis to distinguish between oral cavity and oropharynx tongue. Palatine tonsil is related anteriorly with palatoglossal fold, posteriorly with palatopharyngeal fold, superiorly with soft palate, inferiorly with floor of posterior third of tongue, medially with the cavity of oropharynx and laterally with superior constrictor muscle. Clinical correlation: Tonsillitis is inflammation in any kind of tonsils, since the most common tonsil to be inflamed is the palatine tonsil, tonsillitis generally refers to inflammation in the palatine tonsil, but scientifically inflammation in palatine tonsil is called palatine tonsillitis. Adenoiditis is inflammation in adenoid tonsil.

5 Tonsillitis can be two episodes; acute or chronic. Acute episode lasts for 1-2 weeks, but most cases usually last for 6-7 days. Chronic episode lasts for month. The main difference between acute and chronic tonsillitis is the causative agent, the acute is caused by viral infection like EPV, while the chronic is caused by bacterial infection. To make a proper diagnosis we need to take a swap and make culture. However, since it is very expensive especially in developing countries and it takes time, we prescribe antibiotics. If it is viral, antibiotics will not have any effect so we give NSAID. But if it is chronic bacterial infection we give antibiotic, DOC is amoxicillin, but if the patient is allergic to penicillin we give erythromycin, and in case of resistance as in the developing countries DOC is Azithromycin. If you find pus with white color on the tonsil, this indicates a bacterial infection, but if you find the tonsil swell and very reddish this is an indication for viral infection. Clinical correlation:tonsillectomy is the removal of tonsil, to get rid of the recurrent inflammation. We have rational and indicative tonsillectomy. The rational is because we have recurrent tonsillitis that will interfere with his life activities. In the indicative not any person can undergo tonsillectomy, there an indication to undergo tonsillectomy, the basal one patient should have tonsillitis 7 times per year within one year, 5times per year within two years, or 3 times per year within three years, that would be an indication for tonsillitis. this video is 3:03 minutes represent how tonsillectomy done, see it and then read these comments from doctor about this video: 1) symptoms of tonsillectomy: fever, painful, swallowing and sore throat 2) what is the second step after generalized anesthesia? It s intubation to prevent collapse of genioglossus muscle. 3) the video said intubation occur through your mouth so the intubation can be in your mouth or nose but in tonsillectomy which one preferred? In nose why because we work in mouth so to make working inside mouth more flexible we put the tube for inspiration in nose.

6 4) now we have new procedure for tonsillectomy which is electrocautery electro mean there is an electrical current pass and this current produce heat this heat will )تكوي( cauter the tissues so no bleeding only we need the device to be antiseptic to prevent the infection. this video 3:30 minutes represent real tonsillectomy procedure only see how the surgeon hold the tonsil by forceps and then removing it by electrocautery. C- laryngeopharynx Laryngopharynx, the lower part of the pharynx, it extends from the epiglottis to the base of cricoid cartilage, it is behind the larynx at the level of C4-C6. It continues down with esophagus, and lined with digestive epithelium; nonkeratinized stratified squamous epithelium, the same epithelium as esophagus and oropharynx. The main thing in the laryngopharynx is a depression on the sides

7 called piriform fossa (figure 3, arrow 1)it s appear black shadow in picture, it s a small rescess or depression in each side of the laryngopharynx they bordered medially be a membrane called arytenoepiglottic membrane (quadriangular membrane) of the larynx(figure 3, arrow 2) laterally it s cartilage the thyroid cartilage (figure 3, arrow 3). what is the function of this fossa? This fossa is very important area because during swallowing of sharp objects like fish bones for example, here these fish bones it can through all the esophagus and harm it and also it can harm gastric epithelium and produce several other problems to avoid that the swallowing of these object that usually stab in this area and they don t go through esophagus, something important here also if you looking here there is a very important nerve passing here just before the mucosa this is very important nerve called internal laryngeal nerve which is branch from the vagus so this is important why? Because when the fish bones stuck here on the mucosa of piriform this will lead to irritation of this mucosa this irritation will send signals through the internal laryngeal nerve to the vagus and now the vagus which is responsible for the contraction of constrictor muscles it will produce an action but in an inverted way (I told you that the swallowing represent the successive contraction of constrictor muscles) because the fish bones will not go through esophagus they will stuck in this recess now the internal laryngeal will stimulate the vagus and the vagus will stimulate the constrictor to contract in an inverted way from inferior to superior which called gap reflex, so the gap reflex it s a landmark of contraction of pharyngeal constrictor muscles in an inverted way why it s happen?so now we can get rid of this fish bones backway to outside. Clinical correlation:so why that is the clinical significant? It contains inside it s mucosa internal laryngeal nerve so any object stuck inside it this will produce gap reflex (dentists also suffer from it when they do procedures to patients), in some person if you put your fingers inside his mouth he tends to vomit it s not a vomit it s a gap reflex because irritation of this mucosa usually irritate the vagus to inverted contraction of sphenctor producing a gap reflex.

8 Innervation of the pharynx: the innervation of pharynx similar to structure contain it mean the nosapharynx behind the nose so what is the sensory innervation of the nose? General sensation it s maxillary nerve from the trigeminal nerve so here it will be the maxillary nerve from trigeminal. Oropharynx supply by glossopharyngeal (9) nerve it s same to the posterior third of the tongue and posterior one third of tongue located in the oropharynx so this make sense. Laryngopharynx supply by vagus.so nasopharynx through maxillary division from trigeminal nerve and oropharynx through glossopharynx and laryngopharynx through vagus. For the motor innervation (always we have exception in tongue we have exception represented by palatoglossus which supply by vagus nerve not similar to other tongue muscles that supply by hypoglossus and in palatine we have exception) all muscles of pharynx innervated by vagus nerve through pharyngeal plexus except stylopharyngeus it s innervated by glossopharyngeal nerve. Waldeyer ring: Last thing to talk about pharynx in general aspect is Waldeyer ring. Now when we look here there is oral and nasal opening where the object can enter your body so we need a protection we called it first line of defense, the first line of defense it represents in your body by tonsils in the pharynx, this tonsils should surround these opening nasal opening and oral opening so that is why you will see one pharyngeal tonsil at the top and two tubal elevation in each side behind the nasal opening. now if you go to pharynx behind oral cavity you will see tow palatine

9 tonsils on the lateral walls of oropharynx and lingual tonsil in the floor of oropharynx so it s a collection hexagonal ring; one pharyngeal tonsil above two in the nasopharynx two tubal elevation in the lateral wall of nasopharynx and two palatine tonsils in the wall of oropharynx and one lingual tonsil in the posterior part of the tongue so they provide a hexagonal ring this called waldeyer s tonsillar ring. 2) esophagus and general histology of gastrointestinal tract esophagus it s a muscular tube that pass posterior to trachea (mainly respiratory system anterior and digestive system posterior for example larynx anterior to laryngopharynx and trachea anterior to esophagus. So again esophagus is a muscular tube that lies posterior to trachea and extend from neck (C6) to stomach at the level of (T11) be aware the esophageal opening in the diaphragm is located at the level of (T10) then descend to stomach at level of T11- it s function to transport food to the stomach.

10 Now when we talk about the histology of GIT from esophagus until anal canal they have the basic structure of four layers in histology but they differ slightly according to function we need so sometimes there is a characteristic features for example some has more glands other has more muscles but in general we need four layers in any of GIT as you pass the first layer which is covered by epithelium from inside to outside, the epithelium lining is called the mucosa now when we put cells beside each other (epithelial lining) how we can make it to attach with each other? If there is nothing to hold it together they can easily slash or slough away so to keep it together I put a membrane under the epithelium a connective tissue membrane and put them on it so now the cells stuck to each other by basal membrane that is why we need this basal membrane so you will find beneath epithelium something called lamina الرئيسية( propria )الصفيحة in the mucosa because we need something to put the cells over it to hold them together that is why we need something like lamina propria so the mucosa usually made up of epithelium and below the epithelium always lamina propria. This is the mucosa however the main parts is the epithelium because the lamina propria only to hold the cells with each other. Now the epithelial lining of esophagus is masticator so it s nonkeratinized stratified sequamous epithelium but in the stomach the epithelium becomes digestive one mean columnar epithelium when we enter the intestine become absorptive mean columnar epithelium, at the end of large intestine in the base of rectum and in the anal canal cells begin to become shorter that mean become more cuboidal so the upper part of anal canals is simple cuboidal then after you get behind pectinator line they become nonkeratinized stratified sequamous epithelium and anal canal then to skin which is keratinized stratified sequamous epithelium. Below the mucosa we have another important layer it s a layer of irregular connective tissue it s fiber go in different direction that is called the layer below mucosa or submucosa layer and it s a very important layer why? We need submucosa because here we will have blood vessels and nerves which we need them for any vital organs (VAN) mean any structure to become vital you need

11 VAN which is vein الصحي(,)الصرف artery )الماء( and nerve )الكهرباء( so this is a very important structure passing through submucosa. Then we have a layer responsible for movement peristalsis movement it s muscularis layer or muscularis externa in GIT in general it s consist of tow layers of smooth muscles (the hollow tubes in your body is smooth muscles) these two layers the inner usually circular and the outer for strengthening longitudinal so there is two layers inner circular and outer longitudinal and if you see this gross section this fiber go in this way to complete a circle and this layer go like this why? Because it s longitudinal in column. And after that we need covering (protection) and this is occur by connective tissue called adventitia (very difficult to be seen histologically) and when it s become attached with smooth mesothelial cells we called it serosa (more smooth). So four main layers: mucosa, submucosa, muscularis and adventitia, and in histology lecture we will talk about more special characters to differentiate between the walls of each organ in GIT. In esophagus the upper third is striated muscles not smooth this is the only exception because

12 we know that the muscularis of GIT consist of smooth muscles they contain also smooth muscle fibers but mostly striated muscle fibers more close to skeletal muscles but not same because skeletal muscle attached with skeleton bones but these not mean the same structure of skeletal muscles but without attachment with bone, in middle third of esophagus we have inner circular smooth muscles and outer striated muscles, the lower third is completely smooth muscles. 3) introduction about anteriolateral abdominal wall Now we will talk slightly about new topic which is anterio-lateral abdominal wall? Which is it? Why we will talk about abdominal wall? What is the relationship between abdominal wall and digestive system? May be protection, support of internal organ and pain mean the disease in digestive system can be expressed as abdominal wall pain and this is important clinically so we need to know where is the abdominal wall and what is the relationship between abdominal wall and digestive system? Clinically it s diagnostic for example if I want to test patient liver then I should go upper right so it s very important in clinical examination of digestive system another example appendicitis when there is inflammation in appendix in first stage he pain go with autonomic nervous system but reflex and go with dermatome to terminate in the umbilical region (we called it referred pain we will talk about it later) so appendicitis in early stage there is a pain around umbilicus and you should know that this pain can be indicated for first stage of appendicitis, later appendicitis when the appendix flamed and become with touch with parietal peritoneum and irritating it now we have a lower right third pain this is why we study abdominal wall clinically. Physiologically is important in protection, support of GIT and also the contraction of muscles in this region is very important because when it s contract it will increase the intra-abdominal pressure and this action is very important or we need it in movement of GIT, defecation, urination(urinary system) and during childbirth.

13 Before we start studying anteriolateral abdominal wall to let you know the general structure of human body consist of four layers in human the body is divided to walls and cavities such as cranial, thoracic, abdominal, pelvic cavities. In the limbs no cavity but the wall still there, the wall consists of several layers which are from outside to inside skin, fascia, muscles and skeletal system(bones). The bones in the human body is the keystone structure in your body عمدان االساس في العمارة( )تمثل, the connect structure between bones is muscles الطوب(,)تمثل after that we put insolation layer )القسارة( which represent fascia which covers the muscles and after fascia we have thermal insulation layer represent the adipose tissue. so here we have two types of fascia in human body the superficial fascia or subcutaneous and it s main function is to storage energy but it s also thermal insulation (the superficial fascia in women is thicker than men that is why the women feel cold less than men), and the second type is the deep fascia it s the layer that cover the muscles to make them a one integrity one unit so this will make the contraction and relaxation without fibrous separation we called it engulfing muscle fascia or investing fascia or deep fascia and the final layer provided the color )الدهان( it s the skin. So in any region of human you should see these four layers but there is some specification in each part of body for example in thoracic cavity it s contain a very important vital organ which are lungs and heart that is why we need a very strong protection and this is occur by bone increase over the muscles in the abdominal cavity there are organs that need to move I need peristalsis movement, pressure for defecation, urination and childbirth so the specialization occur in muscles and fascia over the bones. If we go down in the pelvis cavity, what is going

14 there?thereis bones, why bones increase in pelvis cavity? To hold the lower limb because there is a movement large muscles in lower limb need movement and attachment to hold them that is why the bones increase in this area. If we go to cranial cavity the head here we have a completely bone to more and more protection to brain so each region have itsown specification. Linea Linea alba semilunaris Now if we look to anteriolateral abdominal wall there is a skin, a fascia superficial and deep, and then the muscles of the anteriolateral abdominal wall and then we have another type of fascia for protection we called it transversalis fascia because it s covering muscle called transversus abdominis and there is no bone in anteriolateral abdominal wall, in the posterior wall we have bone. But why we study the anteriolateral abdominal wall without posterior abdominal wall? Because in clinical anatomy not in gross anatomy the nerve supply is continuous mean the same nerve supply the lateral and then the anterior, also the fascia that cover muscles is the same one it s continuous they usually over the lateral abdominal muscles then they unite in this groove and split again in the anterior abdominal muscles so any damage to fascia in anterior wall will affect the lateral

15 wall and any damage to lateral fascia affect the anterior fascia it will affect the anterior one, so they are move as a one integrity and that is why we considering it an one subject the anteriolateral abdominal wall important landmark on abdominal wall to distinguish it. We see a semilunar groove here or lineasimilunaris is the demarcated border between anterior and lateral wall of abdominal walls but for us we need to study both as a one unit. In the middle there is another groove that is occur why because there is no muscles only fascia if we take these area and cut in it and reflect the skin what will you see? Is a very white fibrous tissue that is what we called lineaalba (alba mean white) the linea alba is demarcated the midsagittal line in the abdominal wall so we have two important landmarks lineasemilunaris and linea alba and in the next lecture we will continue the anteriolateral abdominal wall. قال تعالى: )وتواصوا بالمرحمة( اعلم من صاحبك اذا كان يوصيك بالرحمة على الناس زميالكما : زكريا الحسنات, محمد النعسان