Body

Your body is very important, it helps you walk, hold stuff and it's body parts are useful. It is true to live without some though. You can live without a Gallbladder, Appendix, one Lung, tailbone/Coccyx, wisdom teeth, Spleen, uterus, one kidney, colon and a bladder. And that is just 10 that is listed. Let us take a journey inside it.
== Mouth ==
The mouth is useful and helps you eat your food. If you had no mouth, you would have to starve and die. Your mouth has teeth. Incisors are flat and board, shaped like a shovel with a narrow straight cutting edge that enables them to cut food. The main functions of an incisor in the mastication process are biting, cutting of food into chewable pieces and moving it inwards the mouth. Your canines are the little, sharp teeth you have. Their main function is to tear and rip meat and other food. Premolars, or bicuspids, are located behind the canines and in front of the molars. There are a total of eight premolars, with four being located on the bottom row of teeth and four located on the top row of teeth. Premolars' main purpose is to chew and crush food, and they are sometimes used for tearing as well. Additionally, premolars help keep the shape of the face, and the absence of premolars can lead to a change in one’s appearance. Premolars are typically very strong and are capable of enduring a large amount of pressure. There are also eight molars (four on the bottom and upper row of teeth). Molars are very strong and are located in the farthest back part of the mouth. The main purpose of molars is to chew and crush food, and they are essential to eating in a normal manner. Third molars, otherwise known as wisdom teeth, are also considered to be molars, although many separate wisdom teeth into their own category. Since molars are exposed to much more jaw pressure than other teeth, it is important to protect them properly by practicing good oral hygiene and wearing a mouthguard at night if grinding teeth while asleep is a problem.
== Oesophagus ==
The esophagus, or oesophagus, informally known as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about 25 cm long in adults, which travels behind the trachea and heart, passes through the diaphragm and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος, from οἴσω, future form of φέρω + ἔφαγον. Barrett’s Oesophagus is the term used for a pre-cancerous condition where the normal cells lining the oesophagus, also known as the gullet or food pipe, have been replaced with abnormal cells. Although the exact cause remains unknown, it is strongly associated with long-term Gastro-Oesophageal Reflux Disease (GORD), which can cause the symptom of heartburn. Approximately 1 in 10 patients with GORD will develop Barrett’s Oesophagus and the risk increases with length and frequency of symptoms. GORD involves reflux of acidic and non-acidic stomach (gastric) contents into the oesophagus, which irritates (inflames) and injures the lining (epithelial cells). Over time, in some patients with GORD, the lining of the oesophagus changes from the normal structure, made up of a type of cells known as “squamous epithelial” cells, to an abnormal type made up from a different type of cells, known as “columnar epithelial” cells. Often (but not always) the lining of the oesophagus starts to resemble the lining of the stomach, in a process known as intestinal metaplasia. Other risk factors that can lead to Barrett’s Oesophagus include older age, male sex, family history, obesity, smoking, high alcohol intake and a hiatus hernia (where the stomach extends abnormally from the abdomen into the chest). Barrett’s Oesophagus can affect men and women, though it is significantly more common in white men, who have a three fold increased risk for the condition.The abnormal cells start from where the oesophagus meets the stomach and spread upwards. The main concern is that, although the majority of patients with Barrett’s Oesophagus do not progress to cancer, oesophageal cancer is the 6th most common cause of cancer death in the UK and 4th most common cause of cancer death in the UK in men. The main symptom of Barrett’s Oesophagus is reflux, which can cause heartburn, regurgitation of food (bringing food back up), nausea and pain in the upper abdomen. You may also experience a metallic taste in your mouth or a chronic sore throat particularly in the mornings as reflux is usually worse after a period spent lying down. Reflux symptoms that wake you at night time are a particularly strong risk factor. Often though, patients with Barrett’s oesophagus do not report symptoms, or manage with over the counter antacids, and this can lead to delay in diagnosis. Barrett’s Oesophagus is diagnosed by examining the oesophagus lining using a procedure called endoscopy. This is where a small tube (the width of a small finger), with a camera on the end is inserted into the oesophagus and stomach via the mouth or nose. Sedation can be used to make the procedure more comfortable. The area of interest is where the oesophagus meets the stomach (gastro-oesophageal junction). Barrett’s Oesophagus is identified when, instead of a normal whitish lining, a pinker lining is seen that extends from the junction and up the oesophagus. Biopsies (a small sample of tissue) are then taken to confirm diagnosis and look for abnormal cells (dysplasia). A pathologist will grade the dysplasia into high grade or low grade. If low grade dysplasia is found then a repeat endoscopy in 6 months is ordered to reassess and consider if referral to a specialist centre for treatment is needed. Patients found to have high grade dysplasia are typically referred more quickly to a specialist centre, as the risk of progression to cancer is higher.
== Lungs ==
The lungs begin at the bottom of your trachea (windpipe). The trachea is a tube that carries the air in and out of your lungs. Each lung has a tube called a bronchus that connects to the trachea. The trachea and bronchi airways form an upside-down “Y” in your chest. This “Y” is often called the bronchial tree. The bronchi branch off into smaller bronchi and even smaller tubes called bronchioles. Like the branches of a tree, these tiny tubes stretch out into every part of your lungs. Some of them are so tiny that they have the thickness of a hair. You have almost 30,000 bronchioles in each lung. Each bronchiole tube ends with a cluster of small air sacs called alveoli (individually referred to as alveolus). They look like tiny grape bunches or very tiny balloons. There are about 600 million alveoli in your lungs. The small bubble shapes of the alveoli give your lungs a surprising amount of surface area — equivalent to the size of a tennis court. This means there’s plenty of room for vital oxygen to pass into your body. The lungs are the primary organs of the respiratory system in humans and many other animals including a few fish and some snails. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible.
== Heart ==
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest.
Category:Biology
Category:Body
Category:Science
Category:Important