In anatomy, heterochromia refers to a difference in coloration, usually of the iris but also of hair or skin. Heterochromia is a result of the relative excess or lack of melanin (a pigment). It may be inherited, or caused by genetic mosaicism, disease, or injury.
Heterochromia of the eye (heterochromia iridis or heterochromia iridum; the common wrong form "heterochromia iridium" is not correct Latin) is of two kinds. In complete heterochromia, one iris is a different color from the other. In partial heterochromia or sectoral heterochromia, part of one iris is a different color from its remainder.
Heterochromia Iridium Causes
This is another physical sign where a good observation can pay dividend at the beginning of the examination.
The heterochromia is usually best seen in a well-lit environment. There are many causes of heterochromia iridis,
however, if the heterochromia forms the main part of the examination (for example 'Look at this patient's eye and do
the necessary examination') the most likely case is siderosis bulbi. Remember that the abnormal eye can be the eye
with either the darker as in siderosis bulbi or the lighter iris for example congenital Horner's syndrome or Fuchs'
Most cases of heterochromia are hereditary, caused by a disease or syndrome, or due to an injury. Sometimes one eye may change color following certain diseases or injuries.
Specific causes of eye color changes include:
Foreign object in the eye
Glaucoma, or some medications used to treat it
Mild inflammation affecting only one eye
Heterochromia iridium (two different-colored eyes within a single individual) and heterochromia iridis (a variety of color within a single iris) are relatively rare in humans and result from increased or decreased pigmentation of the iris. Most cases are isolated and sporadic, conceivably resulting from an alteration in the expression of the above-mentioned genes (and those we have yet to find) within the cells of the entire iris or even a particular section. Other potential causes include trauma around the time of birth or later in life, congenital pigmented nevi or even medications such as those used in the treatment of glaucoma. There are a few well-known syndromes of which heterochromia iridis is a striking feature. Waardenburg syndrome type 1, an autosomal dominant disorder caused by mutations in the PAX3 gene, is characterized by pigmentary disturbances of the iris, hair and skin, as well as congenital sensorineural hearing loss. But two different eye colors tends to be an isolated finding, which adds to the seemingly endless and fascinating variation in humans' physical characteristics.
Radiation Safety Principles and Standard
The International Commission on Radiological Protection (ICRP) has
proposed that following principles should guide the use of ionizing
radiation safety standard:
No practice involving exposures to radiation should be adopted unless it
produces sufficient benefit to the exposed individuals or society to offset
the radiation detriment it causes (the justification of practice)
In relation to any particular source within a practice, the magnitude of
individuals doses, the number of people exposed, and the likelihood on
incurring exposures where these are not certain to be received should all kept
as low as reasonably achievable (ALARA), economic and social factors being
taken into account. This procedure should be constrained by restrictions of
the doses to individuals (dose constraint), so as to limit the inequity likely
to result from the inherent economic and social judgments.
The exposure of individuals resulting from the combination of all the
relevant practices should be subject to dose limits, or to some control of
risk in the case of potential exposures. These are aimed at ensuring that no
individual is exposed radiation risks that are judged to be unacceptable from
these practices in any normal circumstances. Not all sources are susceptible
of control by action at the source and it is necessary to specify the sources
to be included as relevant before selecting a dose limit.
HCG diet shots Are you looking for HCG diet shots? Effect of human chorionic gonadotrophin on weight loss, hunger, and feeling of well-beingW. L. Asher, M.D.1 and Harold W. Harper, M.D.11.From the American Society of Bariatric Physicians Research Council, 333 West Hampden Avenue, Englewood, Colorado 80110.
Twenty female patients on 500 to 550 kcal diets receiving daily injections of 125 IU of human chorionic gonadotrophin (HCG) were compared with 20 female patients on 500 to 550 kcal diets receiving placebo injections. Patients in both groups were instructed to return for daily injections 6 days each week for a total of 36 injections (unless desired weight was achieved prior to this).
The Lymphatics, Respiratory System and Skin The Lymphatics
A large part of the human body is composed of the connective tissue. Within this connective tissue are the lymph cells and the walls of the lymph vessels. The connective tissue is concerned in the formation of blood and blood vessels and also in the formation of lymph vessels.
Through the lymph vessels the white blood cells, which pick up waste material from the body, travel carrying the remains of dead tissue and foreign bodies. The lymph capillaries correspond also to the blood capillaries, the tiniest vessels which form the connection between the arterial and venous blood systems.
Heart Attack Symptoms Warning Signs As the atherosclerotic plaques enlarge, they become cracked and ulcerated. The clotting factors in the blood may treat this ulceration like a cut and form a clot over the plaque, completely blocking the artery. When a branch of a coronary artery becomes totally obstructed, the heart cells that it supplies die, resulting in a heart attack. Heart attack is medically referred to as a myocardial infarction, meaning death of the heart muscle.
Although clot formation over an ulcerated plaque is believed to cause the majority of heart attacks, others are caused when a piece of plaque or clot breaks off, obstructing the artery below the actual site of atherosclerosis. A few may be caused when the diseased artery contracts because of irritation from the plaque. About 1.5 million persons have a heart attack in the United States each year.
Symptoms of meningitis in adults Are you looking for symptoms of meningitis in adults?
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs. Meningitis can be life-threatening because of the inflammation's proximity to the brain and spinal cord; therefore the condition is classified as a medical emergency.
Many of the bacteria and viruses that cause meningitis are fairly common and associated with other routine illnesses. Bacteria and viruses that infect the skin, urinary system, gastrointestinal or respiratory tract can spread by the bloodstream to the meninges through cerebrospinal fluid, the fluid that circulates in and around the spinal cord.
Best countries for Plastic Surgery Are you looking for Best countries for plastic surgery?
Cosmetic plastic surgery includes surgical and nonsurgical procedures that reshape normal structures of the body in order to improve appearance and self-esteem. Healthy individuals with a positive outlook and realistic expectations are appropriate candidates for cosmetic procedures. Plastic surgery is a personal choice and should be done for yourself, not to fulfill someone else's desires or to try to fit an ideal image. Because it is elective, cosmetic surgery is usually not covered by health insurance.
Panic attack symptoms women Are you looking for panic attack symptoms women? Panic attacks may be symptoms of an anxiety disorder. These attacks are a serious health problem in the U.S. At least 20% of adult Americans, or about 60 million people, will suffer from panic attacks at some point in their lives. About 1.7% of adult Americans, or about 3 million people, will have full-blown panic disorder at some time in their lives, twice as often for women than men. The peak age at which people have their first panic attack (onset) is 15-19 years. Another fact about panic is that this symptom is strikingly different from other types of anxiety; panic attacks are so very sudden and often unexpected, appear to be unprovoked, and are often disabling.
Local Treatment of Allergic Dermatitis Most Persons who suffer with allergic dermatitis have accumulated numberless lotions, salves, ointments, and other local preparations. These have either been prescribed for them or suggested to them by their family or friends. For the most part, the effects of these long-continued local applications is to further irritate and traumatize the skin, so that in the end more harm than good is done. First take away all these various drugs and prescribe only such bland preparations as are least likely to injure the skin. These must be cautiously and carefully applied, observing their changing effect. Indeed, at times it is necessary to use the preparation of one area of the skin only, such as one arm or one leg, and observe the difference between the dermatitis on that are and on the area of the body where no preparation has been used.
How to Lose Weight Fast for Teenage Girl without exercise They told him of a party or some event a few weeks in advance and need to lose a few pounds?
Or maybe going to go on holiday and want to look spectacular in the photos.
Fortunately there are some tricks to lose those few extra pounds in no time.
Brain tumour symptoms in adults Are you looking for brain tumour symptoms in adults? More than 18,000 new cases of primary brain tumors are treated each year in the United States. Metastases are even more frequent and contribute considerably to suffering and death from systemic cancer. The diversity of brain tumors makes it important to attend to what is characteristic about each histologic type. Biologic specificity guides therapy to some extent now, and will be the key to successful treatment in the future.
Gangrene Causes, Symptoms and Treatment Gangrene is a term that refers to the death of body tissue due to diminishment or loss of blood supply, leading to nutrient and oxygen deprivation. There are three major types of gangrene: moist, dry, and gas gangrene. Although gangrene usually affects extremities, it can sometimes affect the internal organs.
Managing Your Eating Behavior Letís face it. Eating for health is not easy. It takes knowledge, careful though and analysis, and the ability to put it all together and make the best decisions for your own lifestyle and personal goals within certain budgetary limits. There are no shortcuts, and what is true today may turn out to be false tomorrow. But by paying attention; reading; seeking help from reputable, trained professionals; and planning ahead, you can increase your own nutritional health. The following recommendations will help you improve your nutritional status :