Digestive System Organs PDF

-​ 4 phase of digestion -​ Ingestion ,Digestion, absorption, Elimination -​ Digestive system organs -​ Liver Vs Gallbladder Liver -​ The liver is the largest gland in the body. It lies below the diaphragm in the upper right quadrant of the a...

-​ 4 phase of digestion -​ Ingestion ,Digestion, absorption, Elimination -​ Digestive system organs -​ Liver Vs Gallbladder Liver -​ The liver is the largest gland in the body. It lies below the diaphragm in the upper right quadrant of the abdomen, extending into the upper left quadrant -​ The liver is a vital organ that performs several functions for the body. It secretes bile at a rate of over a pint a day, and the bile is continuously excreted through bile passages to the bile duct. Gallbladder -​ The gallbladder is a small sac attached to the underside of the liver -​ Its sole purpose is the concentration and storage of bile. -​ When the body needs bile to digest food, the gallbladder releases the concentrated bile to supplement that being currently produced by the liver. -​ Concentrated bile is very bitter and is green-yellow in color.The gallbladder empties its contents via the cystic duct. The cystic duct from the gallbladder and the hepatic duct from the liver combine to form the common bile duct -​ Stomach Structure and Function -​ The stomach is a J-shaped organ approximately 10 inches long, located just beneath the diaphragm. It consists of three layers of strong muscle tissue, allowing it to perform its functions effectively. The inner lining is thick and contains folds known as rugae, which enable the stomach to expand and hold about half a gallon of food and liquid. Opening Mechanism -​ The upper opening of the stomach is regulated by the cardiac sphincter, a circular muscle that dilates to allow food entry as the peristaltic wave approaches. Once food enters, the sphincter closes to prevent backflow. Digestive Process -​ Once food is inside, the stomach's muscular layers contract in a rhythmic motion, breaking down food into smaller particles. This mechanical digestion  is complemented by chemical digestion, initiated by the stomach lining's mucous membrane, which secretes mucus and gastric juices. Gastric Glands and Enzymes -​ The stomach contains approximately 35 million gastric glands that secrete hydrochloric acid and various enzymes. Key enzymes include: ​ Rennin: Curds milk. ​ Lipase: Splits certain fats. ​ Pepsin: Digests milk curds formed by rennin. -​ Hydrochloric acid combines with proteins to form compounds that pepsin can further digest. The mucus layer protects the stomach lining from acid damage, but excessive acid can lead to ulcers, particularly gastric or peptic ulcers. Chyme Formation -​ After three to five hours, the stomach transforms partially digested food into a semiliquid substance called chyme. Liquids pass through the stomach quickly, while solid foods are digested in the following order: 1.​ Carbohydrates 2.​ Proteins 3.​ Fats -​ When chyme reaches the appropriate consistency, the pyloric sphincter allows it to enter the small intestine. Vomiting Mechanism -​ The stomach is equipped with two sphincters that hold food until it is ready to exit. However, in cases of nausea, vomiting can occur. This process involves the contraction of abdominal muscles, which forcefully squeezes the stomach while the diaphragm pushes down, creating pressure that expels the stomach's contents through reverse peristaltic waves, resulting in emesis -​ How does carbs affect energy Carbohydrates supply about two-thirds of the energy calories needed each day. -​ Where do we get proteins -​ Proteins are obtained primarily from plants and animal source but not stored by the body -​ Different teeth -​ “Baby” teeth are called deciduous and begin to appear at about six months. They are gradually exchanged for permanent teeth beginning at about six years. -​ Different teeth have specific duties to perform. -​ The incisors bite food with their sharp edges.  -​ The canines or cuspids are pointed to puncture and tear. -​ The premolars or bicuspids and the molars are for grinding and crushing -​ Parts of the small intestine The small intestine is a tube about one inch in diameter and about 20 feet in length. It completes the digestive process and absorbs the nutrients from the chyme. The small intestine is divided into three sections. The first is a C-shaped segment, about nine inches long, called the duodenum. Because this area receives the highest concentration of acid from the stomach, it is especially prone to the development of ulcers. An ulcer in this area is called a duodenal ulcer. The next segment, the jejunum, is about 8 feet in length. The last segment, about 12 feet long, is called the ileum. The jejunum and ileum are suspended in the abdominal cavity by the mesentery, a fan-shaped fold of tissue that is attached to the posterior abdominal wall. The ileum is reduced to about half an inch in diameter by the time it joins the large intestine in the right lower quadrant of the abdomen. The junction is marked by a sphincter called the ileocecal valve, which allows the chyme to enter the cecum (first segment of the large intestine) but prohibits anything from returning to the ileum. -​ Types of diagnostic test -​ How do you prep for GI X Ray Radiologic studies of the GI tract are indicated for a wide variety of reasons and concerned on the various position of the system -​ Barium swallow- If the condition or function of the esophagus is in question, the patient may be asked to drink a radiopaque liquid called barium while the action of the esophagus is observed by fluoroscope. This test is known as a barium swallow. It aids in diagnosing conditions such as dysphagia, hiatus hernia, diverticulosis, and varices. It also detects strictures, tumors, ulcers, and functional disorders. The barium swallow is usually included as part of the more complete GI series. -​ Upper Gi series A barium swallow is performed initially to evaluate the esophagus. Barium is consumed as the progress of the medium is observed by fluoroscope.  X-ray films are taken at specific periods to permit further evaluation. The stomach is compressed to ensure that the barium coats the entire lining. As the barium enters the small intestine, the radiologist manipulates the abdomen to obtain distribution of the barium throughout the bowel loops. The patient is rotated to several positions to record pertinent areas. Spot films may be taken at 30- to 60-minute intervals until peristalsis carries the barium to the ileocecal valve Preparation: An upper GI series is not painful, but the chalky taste and consistency of barium are unpleasant. Preparation for the test may require a two- to three-day diet of low-residue foods before the examination. All oral intake must stop at least eight hours before it is scheduled. The patient must also refrain from smoking. Both a laxative and a cleansing enema may be ordered the evening before the procedure to be certain the tract is empty. Post op- An upper GI series aids in the diagnosis of gastric ulcers, tumors, strictures of the sphincters, inflammation of the lining, motility irregularities, duodenal ulcers, tumors, filling defects, and the like. Following the exam, another laxative may be ordered to aid in removal of the barium from the intestines. Retained barium may cause constipation, obstruction, or fecal impaction. -​ Colonoscopy- An examination to view the entire large intestine using a flexible fiber-optic scope. It is indicated in patients with complaints of diarrhea, constipation, bleeding, or lower abdominal pain. -​ The American Cancer Society recommends a colonoscopy every 10 years, beginning at age 45, as a screening test for colon cancer. Preparation- Starting 24 hours prior to the examination, the patient is allowed only clear liquids or things that become liquid when eaten, such as gelatin. Patients are not allowed to drink or eat anything red or purple such as grape juice or Jell-O. In addition to the diet, the patient will be instructed to take a variety of laxatives depending on the provider’s preference. Laxatives are repeated until the stool becomes nothing but liquid. Twelve hours before the procedure, nothing can be taken by mouth. During/ post op -The patient is sedated and positioned on the left side, with the scope guided through the large intestine. Air is inserted, abdomen manipulation aids, and repositioning facilitates passage. The scope can obtain tissue samples, cytology studies, and polyps snaring.  -​ Cirrhosis of the liver - This chronic disease of the liver causes destruction of the liver cells. The destruction leads to impaired blood and lymph circulation and interferes with the life-preserving functions of the liver. S/sx —Early symptoms include a variety of GI tract signs, such as lack of appetite, indigestion, nausea, vomiting, constipation, and diarrhea. Later, nosebleeds, bleeding gums, edema, mental confusion, and anemia may develop. The liver and spleen become enlarged, jaundice is present, and ascites (collection of fluid) occurs within the abdomen. Because the disease interferes with portal circulation, hypertension occurs in the portal system, causing esophageal varices that eventually rupture and bleed Various blood tests support the diagnosis of cirrhosis, but positive confirmation can be obtained through a liver biopsy. A liver scan will detect abnormal thickening and a mass. Etiology—The most frequent cause of cirrhosis is malnutrition associated with alcoholism. Other causative factors are hepatitis or the suppression of bile flow resulting from a disease of the ducts. Treatment—Treatment consists of taking measures to prevent further damage or complications and dealing with the underlying cause. Dietary changes, supplemental vitamins, rest, and appropriate exercise are indicated. Extra care is required when prescribing drugs because the damaged liver may not be able to process them. Alcohol must be prohibited. It is also important to avoid contact with infections. Mortality is high, with many patients dying within five years of diagnosis. -​ Colorectal cancer- This is a malignancy of the colon or rectum. The American Cancer Society estimated 104,610 new cases of colon cancer and 43,340 new cases of rectal cancer in 2020. It is the third most common cancer in men and women. S/sx —Symptoms can vary in relation to the area involved. With right-side colon involvement, there may be black tarry stools, anemia, abdominal aching, pressure, and dull cramps in the beginning. As the disease progresses, weakness, fatigue, dyspnea, vertigo, and eventually diarrhea, anorexia, weight loss, vomiting, and other signs of intestinal obstruction will occur. There is rectal bleeding, abdominal fullness, cramping, and rectal pressure. Later, there is diarrhea and “ribbon” or pencil-shaped stools. Bright red blood and mucus is in or on the stools. With rectal cancer, the first symptom is a change in bowel habits—often “morning diarrhea” may alternate with obstipation (constipation caused by obstruction). This will be followed by a feeling of incomplete evacuation and later pain and a feeling of rectal fullness. Treatment—The most effective treatment is surgery to remove the tumor, adjacent tissues, and any lymph nodes that may be involved. The type of tumor and extent of involvement determine the surgical procedure. It may involve only the removal of a section of the colon and its supporting structures, to total resectioning of the rectum and the construction of a permanent colostomy. Chemotherapy is indicated with metastasis, residual disease, or a recurring inoperable tumor. Radiation and chemotherapy may be used before surgery to reduce the tumor size and activity and are given following surgery to treat any missed cells. -​ Colostomy ( when does some need a colostomy ) This is an artificial opening of the colon, allowing fecal material to be excreted from the body through the abdominal wall. A colostomy is also indicated when an obstructive growth process, such as a tumor, prohibits the passage of feces. When the growth is close to the end of the rectum, there may not be enough healthy tissue remaining to which a segment of the colon can be attached. There may also be evidence that removal of the affected area, even if possible, would present no advantage. The colostomy patient has a major emotional adjustment in addition to the physical adjustment to make. The alteration in body image may be difficult to accept. The thought of fecal material being expelled into a pouch attached to the abdomen may be very unappealing. Consider also that there is no control over the expulsion of flatus (gas) or stool, and it is easy to understand the new patient’s rejection. -​ Diverticulosis- This is the presence of bulging pouches in the wall of the GI tract where the lining has pushed into the surrounding muscle. The sigmoid colon is the most common site, but diverticuli can occur anywhere from the esophagus to the anus. Signs and Symptoms—Symptoms of diverticulosis (an infected diverticula) include irregular bowel movements, lower left abdominal pain, nausea, flatus, low-grade fever, and an increase in WBCs. Chronic diverticulosis may result in fibrosis and adhesions (tissues growing together) that severely limit or obstruct the lumen. Symptoms progress from constipation to ribbon-like stools, diarrhea, distention (swelling up) of the abdomen, nausea, vomiting, pain, and abdominal rigidity. Treatment—initially consists of preventing constipation and combating infection. A liquid diet, antibiotics, one medication to soften the stool, and another medication to relieve pain and relax muscle spasms are called for. When conservative measures fail, the affected colon section may need to be removed -​ Hepatitis -Hepatitis is an inflammation and infection of the liver that can result in cell destruction and death. Hepatitis B, serum hepatitis, was the first to be identified, over 20 years ago. It is very contagious, with a relatively high mortality rate.. After 15 years, a type C (HCV) was identified. It is the most worrisome form. It usually has a silent beginning but develops into a chronic form that causes the liver to scar. Etiology -Type A is usually transmitted by the fecal-oral route, meaning organisms from sewage, human, or animal wastes get into the food chain. It is usually transmitted through ingestion of food, water, or milk that has been contaminated, and from seafood taken from contaminated water. Type B is usually transmitted parenterally (other than by mouth). Health care workers are especially prone to it because of contact with human secretions and feces. Like AIDS, hepatitis B can also be acquired through sexual intercourse and contaminated needles, including ear piercing and tattooing. It can be passed from mother to newborn during delivery. But it can be spread by more casual contact through cuts in the skin and in saliva. Signs and Symptoms—Hepatitis produces a variety of symptoms, which appear suddenly with type A; type B symptoms are insidious. Clinical features of stage one includes fatigue, malaise, headache, anorexia (lack of appetite), sensitivity to light, sore throat, cough, nausea, vomiting, frequently a fever of 100° to 101°F (37° to 38°C), and possibly liver and lymph node enlargement. These symptoms occur during the preicteric (before jaundice) stage and disappear when jaundice begins. About 6 to 10 percent of adults and 25 to 50 percent of children become chronic carriers. These individuals are infectious and can develop potentially fatal complications because of liver degeneration and cancer. The second, icteric, stage has begun once the urine becomes dark, the stool is clay colored, the sclera and skin is yellow, and a mild weight loss has occurred. The liver remains enlarged and tender, and the spleen and cervical nodes swell. The jaundice may continue for one to two weeks. Then, liver enlargement subsides, but the fatigue, flatulence (intestinal gas), abdominal tenderness, and indigestion continue. The third stage, posticteric, usually lasts for two to six weeks. Full recovery requires six months. Prevention—Vaccines have been developed to prevent hepatitis A and B and are recommended for the following groups of people: ​ Military personnel ​ Persons living in or moving to areas that have a high rate of HAV infection and who are at a high risk of HBV infection ​ Persons engaging in high-risk sexual activity ​ Sexually active gay and bisexual men ​ Persons who use illegal injection drugs ​ Persons at risk through their work, such as laboratory workers who handle live hepatitis A and hepatitis B virus, police, and those who give first aid or medical help, and workers who come in contact with stool or sewage ​ People who work in child daycare centers and correctional facilities, residents of drug and alcohol treatment centers, and patients and staff in hemodialysis units ​ People who are at increased risk for HBV infection and who are in close contact with patients that have hepatitis A or B ​ Persons with hemophilia ​ Persons with chronic liver disease The main problem with the vaccine is it requires three shots over a six-month period and is relatively expensive in the United States. Tx- Hepatitis B has no cure but has various drug treatments like interferon, lamivudine, and adefovir. Patients should rest, eat small meals, and take medication for nausea and vomiting. Hepatitis is a contagious disease, and healthcare workers should wear gloves and isolate patients. The only approved drug therapies are interferon alpha-2 b and ribavirin, which can destroy the virus to undetectable levels in 40% of patients. However, severe side effects and potential virus recurrence make this treatment only a lifesaving measure.