修改chapter7 Digestive system

Chapter 7Digestive systemAnatomy and Physiology of the Digestive SystemThe digestive system has three main functions: digesting food, absorbing nutrients, and eliminating wastes. Digestion is the mechanical and chemical breakdown of food into forms that cell membranes can absorb. Mechanical digestion breaks large pieces into smaller ones without altering their chemical composition. Chemical digestion breaks food into simpler nutrient molecules like glucose, triglycerides and amino acid. These simpler nutrient molecules are absorbed from the intestines and circulated throughout the body by the cardiovascular system. They are used for growth and repair of organs and tissues. Any food that cannot be digested or absorbed becomes a waste product and is expelled.The organs of digestive system are traditionally separated into two major groups: the alimentary canal, or gastrointestinal(GI) tract，and the accessory digestive organs. The alimentary canal is approximately 9 meters long in a cadaver but is considerably shorter in a living person. It consists of the mouth, pharynx, esophagus, stomach, and small and largeintestines(or colon), rectum, and anus. The accessory structures include the salivary glands, gallbladder, liver, and pancreas, each of which is connected to the alimentary canal by a duct, and secrete its products into the alimentary canal.Oral cavityThe digestive system begins when food enters the mouth and is mechanically broken up by the chewing movement of the teeth. The tongue, with its muscular action, moves the food within the mouth and mixes it with saliva. Saliva contains digestive enzymes that break down carbohydrates and lubricants that make it easier to swallow the food. Taste buds are found on the surface of the tongue and can distinguish the bitter, sweet, sour and salty flavors in our food. The roof of the oral cavity is known as the palate. The roof of the mouth consists of the hard palate, the bony anterior portion, and the soft palate, the flexible posterior portion. Hanging down from the posterior edge of the soft palate is the uvula. The uvula serves two important functions. It helps in the production of speech and is the location of gag reflex. The gag reflex helps prevent us from accidentally inhaling food or liquids without first swallowing. The cheeks form the lateral walls of this cavity and the lips are the anterior opening. The entire oral cavity is lined with mucous membrane.TeethTeeth are important for the first stage of digestion. The teeth in the front of the mouth bite, tear, or cut food into small pieces. These cutting teeth include the incisors, and the cuspids, or canines. The remaining teeth grind and crush food into even finer pieces. These grinding teeth include the bicuspids or premolars and the molars. A tooth can be subdivided into the crown and root. The crown is the part of the tooth above the gum line. The root is below the gum line and anchors the tooth in the jaw bone. The crown of the tooth is covered by a layer of enamel, the hardest substance in the body. Under the enamel is dentin, which makes the main bulk of the tooth. The hollow interior of a tooth is the pulp cavity in the crown and root canal in the root. These cavities contain soft tissue made up of blood vessels, nerves and lymph vessels.Humans have two sets of teeth. The first sets, often called baby teeth, or milk teeth, are the deciduous teeth. There are 20 teeth in this set erupt through the gums between ages of 6 to 28 months. At approximately 6 years of age, these teeth begin to fall out and are replaced by the 32 permanent teeth. This replacement process will continue until about 18 to 20 years of age.PharynxAfter food has left the mouth, it enters the oropharynx and then the laryngopharynx. The epiglottis covers the larynx and trachea so that food is shunted away from the lungs and into esophagus.EsophagusThe esophagus is a muscular tube that is about 10 inches long in adults. Food entering the esophagus from the pharynx is delivered to the stomach. The food is propelled along the esophagus by wave-like muscular movement called peristalsis. In fact, peristalsis will work to push food through the entire gut tube.StomachThe stomach is on the left side of the abdominal cavity and is hidden by the liver and diaphragm. This J-shaped muscular organ acts as a bag or sac to collect, churn, digest and store food. Different regions of the stomach are the cardiac region(the area surrounding the cardiac orifice through which food enters the stomach from the esophagus), the fundus (theexpanded portion of the stomach, superolateral to the cardiac region), the body or main portion (midportion of the stomach, inferior to the fundus), and the funnel-shaped pyloric region(consisting of the superior-most pyloric antrum, the more narrow pyloric canal, the terminal pyloris, which is continuous with the small intestine through the pyloric sphincter).The folds in the lining of the stomach are called rugae. When the stomach is filled with food, the rugae are stretched out and disappear. Hydrochloric acid is secreted by glands in the mucous membrane lining of the stomach. Food mixes with HC1 and other gastric juices toform a liquid mixture calledchyme, which then passesthrough the remaining portion ofthe digestive system.The stomach containsmuscular valves calledsphincters, that control the flowof food in one direction only.The cardiac sphincter, namedafter its location near the heart,is located between theesophagus and fundus. It is alsocalled the lower esophagealsphincter. It keeps food frombacking up into the esophagus.The pyloric sphincter opens andcloses to control the passage offood into the small intestines with each opening of sphincter for two important reasons: first, the small intestines are much narrower than the stomach and cannot hold as much as the stomach can. Second, the chyme is highly acidic and must be thoroughly neutralized as it leaves the stomach.Small intestineThe small intestine is a convoluted tube, 6 to 7 meters (about 20 feet) long in a cadaver but only about 2 meters long during life because of muscle tone. It is located between the pyloric sphincter and colon.The small intestine has three sections: the duodenum, the jejunum, and ileum. (1) The duodenum, which extends from the pyloric sphincter to the jejunum, is about 25cm (10 inches) long, and curves around the head of the pancreas. Digestion is completed in the duodenum after partly digested chyme from the stomach is mixed with digestive juices from the pancreas and gallbladder. (2) The jejunum, or middle portion, extends from the middle of the small intestine to the ileum and is about 2.5 m (8 feet) long. Most of the jejunum occupies the umbilical region of the abdominal cavity. (3) The ileum is the last portion of small intestine and extends from the jejunum to the colon. At 3.6m (12 feet) in length, it is the longest portion of small intestine. The ileum connects to the colon through a sphincter called the ileocecal valve.The small intestine is the major site of digestion and absorption of nutrients from food.Because the small intestine is concerned with absorption of food products, an abnormality in this organ can cause malnutrition.ColonFluid that remains after the complete digestion and absorption of nutrients in the small intestine enters the colon or large intestine. Most of this fluid is water and it is reabsorbed into the body. The material that remains after absorption is solid waste called feces. This is the product evacuated in bowel movements.The colon is approximately 5 feet long and extends from the ileocecal valve of the small intestine to the anus. The cecum is a pouch or sac-like area in the first 2-3 inches at the beginning of the colon. The appendix is a small worm-shaped outgrowth at the end of the cecum. The remaining colon consists of the ascending colon, transverse colon, descending colon, and sigmoid colon. The ascending colon on the right side extends from the cecum to the lower border of the liver. The transverse colon begins where the ascending leaves off and moves horizontally across the upper abdomen toward spleen. The descending colon then travels down the left side of the body to where the sigmoid colon begins. The sigmoid colon leads into the rectum. The rectum is the area for storage of feces. The rectum leads into the anus, which contains the anal sphincter. This sphincter is controlled by muscles that assist in the evacuation of feces or defecation.Accessory organs of digestive systemThe accessory organs of the digestive system, the salivary glands, the liver, the pancreas, and gallbladder, generally function by producing much of the digestive fluids and enzymes necessary for the chemical breakdown of food. Each is attached to the gut by a duct. Salivary glandFood in the mouth and mechanical pressure (even chewing rubber bands or wax)stimulate the salivary glands to secrete saliva. This very watery and slick fluid allows food to be swallowed with less danger of choking. Saliva mixed with food in the mouth forms a bolus, which is then ready to be swallowed. Saliva also contains the digestive enzyme amylase that begins the digestion of carbohydrates.There are three pairs of salivary glands. The parotid glands are in front of the ears. The submandibular glands and sublingual glands are in the floor of the mouth.Liver and GallbladderThe liver, the largest glandin the body, is locatedinferior to the diaphragm,more to the right than theleft side of the body. Ithides the stomach from theview in a superficialobservation of theabdominal contents. Thehuman liver has four lobes,and is suspended from thediaphragm and anteriorabdominal wall by thefalciform ligament.The human liver isone of the body’s most important organs, and performs many metabolic functions. However, its digestive function is to produce bile, which leaves the liver through the common hepatic duct and then enters the duodenum through the bile duct. Bile has no enzymatic action but emulsifies fats. Emulsification means the process of breaking up large fat particles into smaller ones and making them more soluble in the watery environment inside the intestines.When digestive activity is not occurring in the digestive tract, bile backs up the cystic duct, and enters the gallbladder, a small, green sac on the inferior surface of the liver. It is stored there until needed for digestive process. While in the gallbladder, bile is concentrated by the removal of water and some ions. When fat-rich food enters the duodenum, a hormonal stimulus causes the gallbladder to contract, releasing the stored bile and making it available to the duodenum.If bile contains an excessive amount of cholesterol and other secretions, it compacts into gallstones. There is a higher incidence of stone formation in women than in men, with obesity increasing the risk. If the common hepatic or bile duct is blocked, bile is prevented from entering the small intestine, accumulates, and eventually backs up into the liver. This exerts pressure on the liver cells, and bile begins to enter the bloodstream. As the bile circulates through the body, the tissue become yellow or jaundiced. Blockage is just one cause of jaundice. More often it results from actual liver problems such as hepatitis or cirrhosis, a condition in which the liver is severely damaged and becomes hard and fibrous.Besides the digestive functions, the liver is very important in the initial processing of nutrient-rich blood draining the digestive organs. And much of the glucose transported to the liver from the digestive system is stored as glycogen in liver for later use, and amino acids are taken from the blood by the liver cells and utilized to make plasma proteins.PancreasThe pancreas is a soft, triangular gland that extends horizontally across the posterior abdominal wall from the spleen to the duodenum. The pancreas produces a whole spectrum of hydrolytic enzymes, which it secretes in an alkaline fluid into the duodenum through the pancreatic duct. Pancreatic juice is very alkaline. It neutralizes the acidic chyme entering the duodenum from the stomach, enabling the pancreatic and intestinal enzymes to operate at their optimal PH. The pancreas is also an endocrine gland. It produces the hormones insulin and glucagon, which play a role in regulating the level of glucose in the blood.Combining forms relating to the digestive systemCombining forms Meaning Examplean/o anus anusappend/o, appendic/o appendix appendectomybucc/o cheek buccolabialcec/o cecum ileocecalcheil/o, labi/o lip cheilorrhaphychol/e bile, gall cholelithiasischolangi/o bile duct cholangiotomycholecyst/o gallbladder cholecystogramcholedoch/o common bile duct choledochectomycol/o, colon/o colon colectomydent/o, odont/o tooth orthodonticsenter/o small intestine enteritisgastr/o stomach gastrodyniagingiv/o gums gingivectomygloss/o tongue hypoglossalhepat/o liver hepatitislapar/o abdomen laparotomylingu/o tongue sublinguallith/o stone lithotripsyor/o mouth oropharynxpalat/o palate palatinepancreat/o pancreas pancreatitispharyng/o pharynx pharyngodyniaproct/o anus and rectum proctoptosisrect/o rectum rectalgiasial/o salivary gland sialolithstomat/o mouth stomatologySuffixes relating to the digestive systemSuffix Meaning Example-emisis vomit hematemesis-lithiasis condition of stones cholelithiasis-orexia appetite anorexia-ostomy surgically creating an opening colostomy-pepsia digestion dyspepsia-phagia eat, swallow polyphagia-prandial pertaing to a meal postprandial-tripsy surgical crushing lithotripsyDiagnostic Procedures Relating to the digestive systemAbdominal ultrasonography Using ultrasound equipment for producing sound wavesto create an image of the abdominal organs.Barium enema Radiographic examination of the small intestine, largeintestine, or colon in which an enema containing barium(Ba)is administered to the patient while X-ray pictures are taken.Also called a lower GI series.Barium swallow A barium(Ba) mixture swallowed while X-ray pictures aretaken of the esophagus, stomach, and duodenum; used tovisualize the upper GI. Also called upper GI series. Gastroscopy A flexible gastroscope is passed through the mouth anddown the esophagus in order to visualize inside the mouth.Used to diagnose peptic ulcers and gastric carcinoma.Liver biopsy Excision of a small piece of liver tissue for microscopicexamination. Generally used to determine if cancer ispresent.Stool culture A laboratory test of feces to determine if any pathogenicbacteria are present.Upper GI series Administering a barium contrast material orally and thentaking an X-ray to visualize the esophagus, stomach, andduodenum. Also called barium swallow.Pathology Relating to the Digestive System1.Gastric cancerGastric cancer can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs and the liver. Stomach cancer causes nearly one million deaths worldwide per year. Stomach cancer is the fourth most common cancer worldwide with 930,000 cases diagnosed in 2002. It is a disease with a highdeath rate (700,000 per year) making it the second most common cause of cancer death worldwide after lung cancer. It is more common in men.EtiologyIt is suspected several risk factors are involved including diet, gastritis, intestinal metaplasia and Helicobacter pylori infection. It is associated with high salt in the diet, smoking, and low intake of fruits and vegetables. Infection with the bacterium H. pylori is the main risk factor in about 80% or more of gastric cancers. A Korean diet, high in salted, stewed and broiled foods, is thought to be a contributing factor. Ten percent of cases show a genetic component. Gastric cancer shows a male predominance in its incidence as up to 3 males are affected for every female. Estrogen may protect women against the development of this cancer form.SymptomsStomach cancer is often asymptomatic or causes only nonspecific symptoms in its early stages. By the time symptoms occur, the cancer has generally metastasized to other parts of the body, one of the main reasons for its poor prognosis. Stomach cancer can cause the following signs and symptoms:Early∙Indigestion or a burning sensation (heartburn)∙Loss of appetite, especially for meatLate∙Abdominal pain or discomfort in the upper abdomen∙Nausea and vomiting∙Diarrhea or constipation∙Bloating of the stomach after meals∙Weight loss∙Weakness and fatigue∙Bleeding (vomiting blood or having blood in the stool), which can lead to anemia∙Dysphagia; this feature suggests a tumor in the cardia or extension of the gastric tumor in to the esophagus.These can be symptoms of other problems such as a stomach virus, gastric ulcer and diagnosis should be done by a gastroenterologist or an oncologist.DiagnosisTo find the cause of symptoms, the doctor asks about the patient's medical history, does a physical exam, and may order laboratory studies. The patient may also have one or all of the following exams:∙Gastroscopic exam is the diagnostic method of choice. This involves insertion of a fibre optic camera into the stomach to visualize it.∙Upper GI series (may be called barium roentgenogram)∙Computed tomography or CT scanning of the abdomen may reveal gastric cancer, but is more useful to determine invasion into adjacent tissues, or the presence of spread to local lymph nodes.Abnormal tissue seen in a gastroscope examination will be biopsied by the surgeon or gastroenterologist. This tissue is then sent to a pathologist for histological examination under a microscope to check for the presence of cancerous cells. A biopsy, with subsequent histological analysis, is the only sure way to confirm the presence of cancer cells.TreatmentLike any cancer, treatment is adapted to fit each person's individual needs and depends on the size, location, and extent of the tumor, the stage of the disease, and general health. Cancer of the stomach is difficult to cure unless it is found in an early stage (before it has begun to spread). Unfortunately, because early stomach cancer causes few symptoms, the disease is usually advanced when the diagnosis is made. Treatment for stomach cancer may include surgery, chemotherapy, and/or radiation therapy. New treatment approaches such as biological therapy and improved ways of using current methods are being studied in clinical trials.SurgerySurgery is the most common treatment for stomach cancer. The surgeon removes part or all of the stomach, as well as some of the tissue around the stomach, with the basic goal of removing all cancer and a margin of normal tissue. Depending on the extent of invasion and the location of the tumor, surgery may also include removal of part of the intestine or pancreas. Endoscopic mucosal resection is a treatment for early gastric cancer that has been pioneered in Japan, but is available in the United States at some centers. In this procedure, the tumor is removed from the wall of the stomach using an endoscope, with the advantage in that it is a smaller operation than removing the stomach. Endoscopic submucosal dissection (ESD) is a similar technique pioneered in Japan, used to resect large sections of mucosa in a successful attempt to decrease gastric cancer recurrence.ChemotherapyThe use of chemotherapy to treat stomach cancer has no established standard of care. Scientists are exploring the benefits of giving chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy remaining cancer cells. Combination treatment with chemotherapy and radiation therapy is also under study. Doctors are testing a treatment in which anticancer drugs are put directly into the abdomen (intraperitoneal hyperthermic chemoperfusion). Chemotherapy also is being studied as a treatment for cancer that has spread, and as a way to relieve symptoms of the disease. The side effects of chemotherapy depend mainly on the drugs the patient receives.Radiation therapyRadiation therapy (also called radiotherapy) is the use of high-energy rays to damage cancer cells and stop them from growing. When used, it is generally in combination with surgery and chemotherapy, or used only with chemotherapy in cases where the individual is unable to undergo surgery. Radiation therapy may be used to relieve pain or blockage by shrinking the tumor for palliation of incurable disease2.Peptic ulcer diseaseA peptic ulcer, also known as ulcus pepticum, PUD(peptic ulcer disease), is an ulcer (defined as mucosal erosions equal to or greater than 0.5 cm) of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. As much as 80% of ulcers are associated with Helicobacter pylori, a spiral-shaped bacterium that lives in the acidic environment of the stomach, however only 20% of those cases go to a doctor. Ulcers can also be caused or worsened by drugs such as aspirin and other NSAIDs(non-steroid anti-inflammatory drugs). Contrary to general belief, more peptic ulcers arise in the duodenum (first part of the small intestine, just after the stomach) than in the stomach. About 4% of stomach ulcers are caused by a malignant tumor, so multiple biopsies are needed to make sure. Duodenal ulcers are generally benign.ClassificationA peptic ulcer may arise at various locations:∙Stomach (called gastric ulcer)∙Duodenum (called duodenal ulcer)∙Esophagus (called esophageal ulcer)Types of peptic ulcers:∙Type I: Ulcer along the lesser curve of stomach∙Type II: Two ulcers present - one gastric, one duodenal∙Type III: Prepyloric ulcer∙Type IV: Proximal gastresophageal ulcer∙Type V: Anywhere along gastric body, NSAID(non-steroid anti-inflammatory drugs) inducedSigns and symptomsSymptoms of a peptic ulcer can be∙abdominal pain, classically epigastric with severity relating to mealtimes, after around3 hours of taking a meal (duodenal ulcers are classically relieved by food, while gastriculcers are exacerbated by it);∙bloating and abdominal fullness;∙waterbrash (rush of saliva after an episode of regurgitation to dilute the acid in esophagus);∙nausea, and lots of vomiting;∙loss of appetite and weight loss;∙hematemesis (vomiting of blood); this can occur due to bleeding directly from a gastric ulcer, or from damage to the esophagus from severe/continuing vomiting.∙melena (tarry, foul-smelling feces due to oxidized iron from hemoglobin);∙rarely, an ulcer can lead to a gastric or duodenal perforation. This is extremely painful and requires immediate surgery.A history of heartburn, gastroesophageal reflux disease (GERD) and use of certain forms of medication can raise the suspicion for peptic ulcer. Medicines associated with peptic ulcer include NSAID (non-steroid anti-inflammatory drugs) and most glucocorticoids (e.g. dexamethasone and prednisolone).The timing of the symptoms in relation to the meal may differentiate between gastric and duodenal ulcers: A gastric ulcer would give epigastric pain during the meal, as gastric acid is secreted, or after the meal, as the alkaline duodenal contents reflux into the stomach. Symptoms of duodenal ulcers would manifest mostly before the meal—when acid (production stimulated by hunger) is passed into the duodenum. However, this is not a reliable sign in clinical practice.Complications∙Gastrointestinal bleeding is the most common complication. Sudden large bleeding can be life-threatening. It occurs when the ulcer erodes one of the blood vessels.∙Perforation (a hole in the wall) often leads to catastrophic consequences. Erosion of the gastro-intestinal wall by the ulcer leads to spillage of stomach or intestinal content into the abdominal cavity. Perforation at the anterior surface of the stomach leads to acute peritonitis, initially chemical and later bacterial peritonitis. The first sign is often sudden intense abdominal pain. Posterior wall perforation leads to pancreatitis; pain in this situation often radiates to the back.∙Penetration is when the ulcer continues into adjacent organs such as the liver and pancreas.∙Scarring and swelling due to ulcers causes narrowing in the duodenum and gastric outlet obstruction. Patient often presents with severe vomiting.∙Pyloric stenosisStress and ulcersDespite the finding that a bacterial infection is the cause of ulcers in 80% of cases, bacterial infection does not appear to explain all ulcers and researchers continue to look at stress as a possible cause, or at least a complication in the development of ulcers.An expert panel convened by the Academy of Behavioral Medicine Research concluded that ulcers are not purely an infectious disease and that psychological factors do play a significant role. Researchers are examining how stress might promote H. pylori infection. For example, Helicobacter pylori thrives in an acidic environment, and stress has been demonstrated to cause the production of excess stomach acid.A study of peptic ulcer patients in a Thai hospital showed that chronic stress was strongly associated with an increased risk of peptic ulcer, and a combination of chronic stress and irregular mealtimes was a significant risk factor.DiagnosisAn esophagogastroduodenoscopy (EGD), a form of endoscopy, also known as a gastroscopy, is carried out on patients in whom a peptic ulcer is suspected. By direct visual identification, the location and severity of an ulcer can be described. Moreover, if no ulcer is present, EGD can often provide an alternative diagnosis.The diagnosis of Helicobacter pylori can be made by:∙Urea breath test (noninvasive and does not require EGD);∙Direct culture from an EGD biopsy specimen; this is difficult to do, and can be expensive. Most labs are not set up to perform H. pylori cultures;∙Direct detection of urease activity in a biopsy specimen by rapid urease test;∙Measurement of antibody levels in blood (does not require EGD). It is still somewhat controversial whether a positive antibody without EGD is enough to warrant eradication therapy;∙Stool antigen test;∙Histological examination and staining of an EGD biopsy.TreatmentYounger patients with ulcer-like symptoms are often treated with antacids or H2 antagonists before EGD is undertaken. Bismuth compounds may actually reduce or even clear organisms, though it should be noted that the warning labels of some bismuth subsalicylate products indicate that the product should not be used by someone with an ulcer.Patients who are taking nonsteroidal anti-inflammatories (NSAIDs) may also be prescribed a prostaglandin analogue (Misoprostol) in order to help prevent peptic ulcers, which may be a side-effect of the NSAIDs.When H. pylori infection is present, the most effective treatments are combinations of 2 antibiotics (e.g. Clarithromycin, Amoxicillin, Tetracycline, Metronidazole) and 1 proton pump inhibitor (PPI), sometimes together with a bismuth compound. In complicated, treatment-resistant cases, 3 antibiotics (e.g. amoxicillin + clarithromycin + metronidazole) may be used together. An effective first-line therapy for uncomplicated cases would be Amoxicillin + Metronidazole + Rabeprazole (a PPI). In the absence of H. pylori, long-term higher dose PPIs are often used.Treatment of H. pylori usually leads to clearing of infection, relief of symptoms and eventual healing of ulcers. Recurrence of infection can occur and retreatment may be required, if necessary with other antibiotics. Since the widespread use of PPI's in the 1990s, surgical procedures (like "highly selective vagotomy") for uncomplicated peptic ulcers became obsolete.Perforated peptic ulcer is a surgical emergency and requires surgical repair of the perforation. Most bleeding ulcers require endoscopy urgently to stop bleeding with cautery or injection.Vocabularies Relating to the Digestive Systemalimentary [ ✌●♓❍♏⏹♦☜❒♓] 食物的，营养的amino acid [ ✌❍♓⏹☜◆ ✌♦✋♎] 氨基酸bicuspid [♌♋♓✈♦☐♓♎] 两尖齿，前磨牙canine [ ♏♓⏹♋♓⏹]犬牙，犬齿cardiac region [ ♎♓✌] 心脏的, (胃的)贲门的chyme [ ♋♓❍] 食糜cuspid [ ✈♦☐♓♎] 犬牙cystic duct [ ♦♓♦♦♓ ♎✈♦] 晶体管deciduous teeth [♎♓♦♓♎✞◆☜♦] 乳牙dentin [♊♎♏⏹♦✋⏹] 牙本质duodenum [ ♎◆☎✆☜◆♎♓⏹☜❍] 十二指肠emulsification [♓❍✈●♦♓♐♓♏♓☞☜⏹] 乳化, 乳化作用enamel[♓⏹✌❍☜●] 牙釉质epiglottis [ ♏☐♓♈●♦♓♦] 会厌esophagus [♓☎✆♦♐☜♈☜♦] 食管，食道falciform ligament. [ ♐✌●♦♓♐❍ ☯●♓♈☜❍☜⏹♦] 镰状韧带。