The gastrointestinal (GI) tract is a long, hollow tube extending from the mouth to the anal canal. It consists of a variety of cells that aid in digestion, absorption and secretion. Cell types from the mouth to the anal canal are briefly discussed.
While the pain you’re feeling after drinking milk may seem to resemble some of those associated with lactose intolerance, the discomfort in this condition is almost always gastrointestinal. With an intolerance to lactose, drinking milk often...
An eye, or corneal, ulcer is an area of infection or inflammation in the cornea. These can be caused by bacteria, viruses, parasitic organisms, fungi or the organism Acanthamoeba. Eye ulcers present with pain, eye redness and decreased vision. If...
Squamous cell carcinoma is a malignant tumor of squamous epithelium. Squamous epithelium is a tissue that lines most surfaces of the body both externally, such as the skin, and internally where it lines many organs. Squamous epithelium has a...
Laser eye surgery is a vision correction option for many people with nearsightedness, farsightedness or astigmatism. These vision problems are called refractive errors. Laser vision-correction procedures reshape the cornea--the clear area at the...
Back in the not too distant past, it was commonly believed that eating too much spicy food or the physiological side effects of stress caused stomach ulcers. It is now known that a bacteria called Helicobacter pylori is the cause of the vast...
Epithelial cells are specialized cells which line many different kinds of tissue. Columnar epithelial cells are named because they are somewhat rectangular in shape and resemble a column in their orientation. Columnar epithelial cells are often...
Simple squamous epithelium consists of a single layer of thin cells that are often flattened. These cells have a variety of functions within the body and are primarily used to line certain tissues. These cells are used to make very thin linings...
Barrett's disease, also called Barrett's esophagus, is a complication of gastroesophageal reflux disease, or GERD. At the junction where the esophagus meets the stomach is a circular muscle, or sphincter, that closes after food or liquids enter...
Vitamin A plays an essential role in the maintenance of epithelial cells. Epithelial cells carry out a number of critical functions in the body, and a lack of vitamin A can cause a variety of conditions affecting the skin, eye, lungs, urinary...
Oxygen is transported by your red blood cells to all the organs and tissues of your body. This happens in the alveoli, which are the final branchings of your lungs, where oxygen diffuses through the alveolar epithelium into your alveolar...
Wouldn't it be nice to grow a new tooth to replace a broken or infected one? That's what the new area of dentistry called regenerative dentistry encompasses. Dr. Paul Sharpe, a researcher into dentistry at King's College in London, created the...
The white part of your eyeball is called the sclera, and the black part is known as the pupil. The pupil performs like a camera shutter and controls the amount of light entering the lens and retina located behind it. When you visit an eye...
Melatonin keeps your body on schedule, maintaining your internal 24-hour clock and regulating hormones, including those associated with the reproductive system. Your body naturally produces melatonin, but levels drop as you age. Melatonin...
Age brings with it wisdom, experience and the unfortunate decline of your eyesight. Around age 40, you'll probably notice that print is harder to read. It's an inconvenience easily remedied by a good pair of reading glasses. After age 60 though, a...
Frequent urination is the urge to urinate more often than normal during the day, at night or both. During urination, a person with frequent urination may void a normal or less than normal amount of urine. Dysuria, or painful urination, is a...
Keratoconus is a degenerative eye condition that thins the cornea, pushing it into a cone-like shape. The change in cornea shape causes vision problems, including nearsightedness and astigmatism. Causes of keratoconus range from genetic conditions...
Carrots, rich in vitamins A, C, K and potassium have many health benefits. They can help reduce cholesterol, prevent heart attacks and fight off certain types of cancer, reports OrganicFacts.net. They can also improve your eyesight and reduce your...
The integumentary system consists of the skin--the body's largest organ--and its accessory features and glands. Like other body organs, the skin is essential to maintenance of life and health, and has functions including temperature regulation and...
The vaginal lining, also known as the epithelium or mucosa, is a normally thick, moist, folded surface of mucous membranes that collapses on itself. Beneath the mucosa, muscular and fibrous tissue allow the vagina to expand or contract and to...
The eye is a complex organ, composed of many different structures with varying sensitivity to the effects of radiation. An easy way to look at the eye is to divide it into zones that can be examined with respect to their susceptibility to...
The body's largest organ is the skin, weighing about 6 lbs., according to the University of Maryland Medical Center. It is essential in safeguarding the body from external deterrents that can damage internal organs. It acts to maintain body...
Black cohosh, a medicinal herb originating in North America, has been used for centuries as a treatment for women's health problems. The National Center for Complementary and Alternative Medicine notes that black cohosh has been used historically...
Contact lenses can be used to correct visual acuity in people who are nearsighted (myopic), farsighted (hyperopic) and have irregular corneas (astigmatism). According to the Association of Contact Lens Manufacturers, there are 31 million people in...
The cornea is the first line of defense against injury to the eye. The dome-shaped, clear tissue of the cornea covers the iris, the colored part of the eye, and the pupil, the hole that adjusts to let light into the eye. Diseases that damage the...
If you are a smoker and find that you get dead skin inside your mouth, you should not be surprised. Mouth changes with tobacco use. The lining of the oral cavity is composed of layers of flat scale-like cells called squamous epithelium. Tobacco...
Colon cancer is a malignancy of the colon, or large intestine, a shallow digestive tube extending from the cecum to the rectum. In most cases, colon cancers begin as polyps, which are growths--clinically known as adenocarcinomas--projecting from...
Conjunctivitis is an inflammation of the conjunctiva, which is the clear vascular covering of the sclera and the eyelids. Infectious conjunctivitis can be caused by either bacterial or viral infection; however, viral conjunctivitis often is...
