domingo, 28 de abril de 2013

25. - DIGESTIVE SYSTEM



25. - DIGESTIVE SYSTEM

The human digestive system is a complex series of organs and glands that processes food. In order to use the food we eat, our body has to break the food down into smaller molecules that it can process; it also has to excrete waste.
Most of the digestive organs (like the stomach and intestines) are tube-like and contain the food as it makes its way through the body. The digestive system is essentially a long, twisting tube that runs from the mouth to the anus, plus a few other organs (like the liver and pancreas) that produce or store digestive chemicals.

The Digestive Process:
The start of the process - the mouth: The digestive process begins in the mouth. Food is partly broken down by the process of chewing and by the chemical action of salivary enzymes (these enzymes are produced by the salivary glands and break down starches into smaller molecules).
On the way to the stomach: the esophagus: After being chewed and swallowed, the food enters the esophagus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements (called peristalsis) to force food from the throat into the stomach. This muscle movement gives us the ability to eat or drink even when we're upside-down.

In the stomach: The stomach is a large, sack-like organ that churns the food and bathes it in a very strong acid (gastric acid). Food in the stomach that is partly digested and mixed with stomach acids is called chyme.
In the small intestine: After being in the stomach, food enters the duodenum, the first part of the small intestine. It then enters the jejunum and then the ileum (the final part of the small intestine). In the small intestine, bile (produced in the liver and stored in the gall bladder), pancreatic enzymes, and other digestive enzymes produced by the inner wall of the small intestine help in the breakdown of food.
In the large intestine: After passing through the small intestine, food passes into the large intestine. In the large intestine, some of the water and electrolytes (chemicals like sodium) are removed from the food. Many microbes (bacteria like Bacteroides, Lactobacillus acidophilus, Escherichia coli, and Klebsiella) in the large intestine help in the digestion process. The first part of the large intestine is called the cecum (the appendix is connected to the cecum). Food then travels upward in the ascending colon. The food travels across the abdomen in the transverse colon, goes back down the other side of the body in the descending colon, and then through the sigmoid colon.
The end of the process: Solid waste is then stored in the rectum until it is excreted via the anus.

DIGESTIVE SYSTEM DISORDERS

Digestive system disorders happen when there is a faulty function during the process of digestion which prevents some part of the digestive system from working as it should do. There are many common digestive system disorders.


The function of the digestive system is to take the food and liquids that we put into our
mouths and then either turn them into nutrients and energy needed by the cells of our body, turning what the body doesn't absorb into waste products to be expelled by our body as bowel movements.
Digestive system disorders happen when there is a faulty function during the process of digestion which prevents some part of the digestive system from working as it should do.

PHYSICAL EXAMINATION
A physical examination, medical examination, or clinical examination (more popularly known as a check-up or medical) is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient. Together with the medical history, the physical examination aids in determining the correct diagnosis and devising the treatment plan. This data then becomes part of the medical record.

IMAGING TECHNIQUE
Medical imaging is the technique and process used to create images of the human body (or parts and function thereof) for clinical purposes (medical procedures seeking to reveal, diagnose, or examine disease) or medical science (including the study of normal anatomy and physiology). Although imaging of removed organs and tissues can be performed for
medical reasons, such procedures are not usually referred to as medical imaging, but rather are a part of pathology.
As a discipline and in its widest sense, it is part of
biological imaging and incorporates radiology (in the wider sense), nuclear medicine, investigative radiological sciences, endoscopy, (medical) thermography, medical photography, and microscopy (e.g. for human pathological investigations).
Measurement and recording techniques which are not primarily designed to produce
images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (EKG), and others, but which produce data susceptible to be represented as maps (i.e., containing positional information), can be seen as forms of medical imaging.
Up until 2010, 5 billion medical imaging studies had been conducted worldwide.
Radiation exposure from medical imaging in 2006 made up about 50% of total ionizing radiation exposure in the United States.
 
In the clinical context, "invisible light" medical imaging is generally equated to
radiology or "clinical imaging" and the medical practitioner responsible for interpreting (and sometimes acquiring) the images is a radiologist. "Visible light" medical imaging involves digital video or still pictures that can be seen without special equipment. Dermatology and wound care are two modalities that utilize visible light imagery. Diagnostic radiography designates the technical aspects of medical imaging and in particular the acquisition of medical images. The radiographer or radiologic technologist is usually responsible for acquiring medical images of diagnostic quality, although some radiological interventions are performed by radiologists. While radiology is an evaluation of anatomy, nuclear medicine provides functional assessment.

As a field of scientific investigation, medical imaging constitutes a sub-discipline of
biomedical engineering, medical physics or medicine depending on the context: Research
and development in the area of instrumentation, image acquisition (e.g. radiography), modeling and quantification are usually the preserve of biomedical engineering, medical physics, and computer science; Research into the application and interpretation of medical images is usually the preserve of radiology and the medical sub-discipline relevant to medical condition or area of medical science (neuroscience, cardiology, psychiatry, psychology, etc.) under investigation. Many of the techniques developed for medical imaging also have scientific and industrial applications.
Medical imaging is often perceived to designate the set of techniques that noninvasively produce images of the internal aspect of the body. In this restricted sense, medical imaging can be seen as the solution of
mathematical inverse problems. This means that cause (the properties of living tissue) is inferred from effect (the observed signal). In the case of ultrasonography the probe consists of ultrasonic pressure waves and echoes inside the tissue show the internal structure. In the case of projection radiography, the probe is X-ray radiation which is absorbed at different rates in different tissue types such as bone, muscle and fat.
The term noninvasive is a term based on the fact that following medical imaging modalities do not penetrate the skin physically. But on the electromagnetic and radiation level, they are quite invasive. From the high energy photons in X-Ray Computed Tomography, to the 2+ Tesla coils of an MRI device, these modalities alter the physical and chemical environment of the body in order to obtain data.
LIVER DISORDERS Liver disease (also called hepatic disease) is an umbrella term referring to damage to or
disease of the liver.
Signs and symptoms
The symptoms related to liver dysfunction include both physical signs and a variety of symptoms related to digestive problems, blood sugar problems, immune disorders, abnormal absorption of fats, and metabolism problems.
The malabsorption of fats may lead to symptoms that include indigestion, reflux, deficit of fatsoluble vitamins,
hemorrhoids, gall stones, intolerance to fatty foods, intolerance to alcohol, nausea and vomiting attacks, abdominal bloating, and constipation.
Nervous system disorders include depression, mood changes, especially anger and irritability, poor concentration and "
foggy brain", overheating of the body, especially the face and torso, and recurrent headaches (including migraine) associated with nausea.
The blood sugar problems include hypoglycaemia.
Abnormalities in the level of fats in the blood stream, whether too high or too low levels of lipids in the organism. Hypercholesterolemia: elevated LDL cholesterol, reduced HDL cholesterol, elevated triglycerides, clogged arteries leading to high blood pressure, heart attacks and strokes, build up of fat in other body organs (fatty degeneration of organs), lumps of fat in the skin (lipomas and other fatty tumors), excessive weight gain (which may lead to obesity), inability to lose weight even while dieting, sluggish metabolism, protuberant abdomen (pot belly), cellulite, fatty liver, and a roll of fat around the upper abdomen (liver roll) etc. Or too low levels of lipids: hypocholesterolemia: low total cholesterol, low LDL and VLDL cholesterol, low triglyderides.

RECTAL CANCER APPENDICITIS
The appendix is a small hollow tube attached to the large colon (the large colon is also called large bowel or large intestine). The appendix is approximately 4 inches long and shaped like a worm. The appendix serves no known purpose, although it is thought to possibly play a role in the immune system. Very rarely, the appendix may become cancerous. Since the appendix is attached to the colon, appendix cancer is considered a type of colorectal cancer. Colorectal cancers are also part of a larger group of cancers of gastrointestinal tract, or GI cancers.
Cancer of the appendix may cause appendicitis or cause the appendix to rupture. Sometimes this is the first symptom of appendix cancer. A ruptured appendix may cause a very serious condition called peritonitis, which is an infection of the lining of the abdomen and pelvis. A cancerous tumor of the appendix may also "seed" the abdomen with cancer cells. This may cause more cancerous tumors to develop in the abdomen before it is discovered. See
Peritoneal Surface Malignancies and Peritoneal Carcinomatosis. Many times there are no symptoms of appendix cancer until it has progressed and is advanced. Abdominal discomfort and bloating of the abdomen can be signs of advanced appendiceal cancer.
There are five most common (though still VERY rare) varieties of appendix cancer: Malignant Carcinoid, Mucinous Adenocarcinoma, Adenocarcinoma, Adenocarcinoid, and Signet Ring Adenocarcinoma. To learn more about these varieties of appendix cancer, treatment and prognosis, click the links here or on the left side of this screen.

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