The eyes A close up of a young person's eyes. The eyes are responsible for four-fifths of all the information our brain receives. Here you can find out a bit more about how they work, common problems that affect vision and the work Sightsavers does to treat and prevent avoidable blindness. You can also find out more about the people whose lives have been changed thanks to donations from people like you. How do eyes work? (click image to see enlarged version or click here for text alternative) Graphic of an eye with information about its different parts The images we see are made up of light reflected from the objects we look at. This light enters the eye through the cornea. Because this part of the eye is curved, it bends the light, creating an upside down image on the retina (this is eventually put the right way up by the brain). The retina is a complex part of the eye, but only the very back of it is light sensitive. This part of the retina has roughly the area of a 10p coin, and is packed with photosensitive cells called rods and cones. Cones are the cells responsible for daylight vision. There are three kinds – each responding to a different wavelength of light: red, green and blue. The cones allow us to see images in colour and detail. Rods are responsible for night vision. They are sensitive to light but not to colour. In darkness, the cones do not function at all. How do we see an image? The lens focuses the image. It can do this because it is adjustable – using muscles to change shape and help us focus on objects at different distances. The automatic focusing of the lens is a reflex response and is not controlled by the brain. Once the image is clearly focused on the sensitive part of the retina, energy in the light that makes up that image creates an electrical signal. Nerve impulses can then carry information about that image to the brain through the optic nerve.

The term "miniaturization" is widely accepted in our vernacular as a positive step in product development. Reducing components to create less space, product footprint and more affordable medical devices are ongoing objectives for manufacturers today. Jabil strives to integrate new innovative technologies into product design and manufacturing as continual miniaturization of medical devices is a focus of the healthcare thought process. Miniaturization is a constantly moving target. Once a novel, new technology sets a higher bar for miniaturization standards, the next ambitious goal is to achieve an even thinner and smaller device. Industry trends, including minimally invasive surgical devices and home health care delivery, demand more sophisticated medical portable devices and easy-to-use electronics which may not be a core competency of medical device manufacturers.

Bone fractures are generally caused by injury, such as a fall, car accident, or sports injury, however, bone fractures can also be caused by osteoporosis. If you have a bone fracture, you must get immediate medical attention and keep the fracture immobilized until you can get help. After the fracture has been immobilized, you can then begin natural remedies to help heal broken bones fast.

Blood clotting, or coagulation, is an important process that prevents excessive bleeding when a blood vessel is injured. Platelets (a type of blood cell) and proteins in your plasma (the liquid part of blood) work together to stop the bleeding by forming a clot over the injury.

Three cholinesterase inhibitors are commonly prescribed: Donepezil (Aricept) is approved to treat all stages of Alzheimer's. Rivastigmine (Exelon) is approved to treat mild to moderate Alzheimer's. Galantamine (Razadyne) is approved to treat mild to moderate Alzheimer's. Currently, there is no cure for Alzheimer's. But drug and non-drug treatments may help with both cognitive and behavioral symptoms. Researchers are looking for new treatments to alter the course of the disease and improve the quality of life for people with dementia. ... Medications for Memory Loss.

Reading the 12-lead ECG

Thymoma is a tumor originating from the epithelial cells of the thymus. Thymoma is an uncommon tumor, best known for its association with the neuromuscular disorder myasthenia gravis; thymoma is found in 20% of patients with myasthenia gravis. Once diagnosed, thymomas may be removed surgically.

wound clean from pus

The timing of the nausea or vomiting can indicate the cause. When appearing shortly after a meal, nausea or vomiting may be caused by food poisoning, gastritis (inflammation of the stomach lining), an ulcer, or bulimia. Nausea or vomiting one to eight hours after a meal may also indicate food poisoning.

Neonatal resuscitation skills are essential for all health care providers who are involved in the delivery of newborns. The transition from fetus to newborn requires intervention by a skilled individual or team in approximately 10% of all deliveries. This figure is concerning because 81% of all babies in the United States are born in nonteaching, nonaffiliated level I or II hospitals. In such hospitals, the volume of delivery service may not be perceived as sufficient economic justification for the continuous in-hospital presence of personnel with high-risk delivery room experience, as recommended by the American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG). [1] Perinatal asphyxia and extreme prematurity are the 2 complications of pregnancy that most frequently necessitate complex resuscitation by skilled personnel. However, only 60% of asphyxiated newborns can be predicted ante partum. The remaining newborns are not identified until the time of birth. Additionally, approximately 80% of low-birth-weight infants require resuscitation and stabilization at delivery. Nearly one half of newborn deaths (many of which involve extremely premature infants) occur during the first 24 hours after birth. Many of these early deaths also have a component of asphyxia or respiratory depression as an etiology. For the surviving infants, effective management of asphyxia in the first few minutes of life may influence long-term outcome. Even though prenatal care can identify many potential fetal difficulties ante partum, allowing maternal transfer to the referral center for care, many women who experience preterm labor are not identified prospectively and therefore are not appropriately transferred to a tertiary perinatal center. Consequently, many deliveries of extremely premature infants occur in smaller hospitals. For this reason, all personnel involved in delivery room care of the newborn should be trained adequately in all aspects of neonatal resuscitation. Additionally, equipment that is appropriately sized to resuscitate infants of all gestational ages should be available in all delivering institutions, even if the institution does not care for preterm or intensive care infants. Along with the necessary skills, the practitioner should approach any resuscitation with a good comprehension of transitional physiology and adaptation, as well as an understanding of the infant's response to resuscitation. Resuscitation involves much more than possessing an ordered list of technical skills and having a resuscitation team; it requires excellent assessment skills and a grounded understanding of physiology.

Chronic obstructive pulmonary disease Email this page to a friend Print Facebook Twitter Google+ Chronic obstructive pulmonary disease (COPD) is a common lung disease. Having COPD makes it hard to breathe. There are two main forms of COPD: Chronic bronchitis, which involves a long-term cough with mucus Emphysema, which involves damage to the lungs over time Most people with COPD have a combination of both conditions. Causes Smoking is the main cause of COPD. The more a person smokes, the more likely that person will develop COPD. But some people smoke for years and never get COPD. In rare cases, nonsmokers who lack a protein called alpha-1 antitrypsin can develop emphysema. Emphysema Other risk factors for COPD are: Exposure to certain gases or fumes in the workplace Exposure to heavy amounts of secondhand smoke and pollution Frequent use of a cooking fire without proper ventilation Symptoms Symptoms may include any of the following: Cough, with or without mucous Fatigue Many respiratory infections Shortness of breath (dyspnea) that gets worse with mild activity Trouble catching one's breath Wheezing Because the symptoms develop slowly, some people may not know that they have COPD.

Ehlers-Danlos syndrome is a group of disorders that affect the connective tissues that support the skin, bones, blood vessels, and many other organs and tissues. Defects in connective tissues cause the signs and symptoms of Ehlers-Danlos syndrome, which vary from mildly loose joints to life-threatening complications. Previously, there were more than 10 recognized types of Ehlers-Danlos syndrome, differentiated by Roman numerals. In 1997, researchers proposed a simpler classification that reduced the number of major types to six and gave them descriptive names: the classical type (formerly types I and II), the hypermobility type (formerly type III), the vascular type (formerly type IV), the kyphoscoliosis type (formerly type VIA), the arthrochalasia type (formerly types VIIA and VIIB), and the dermatosparaxis type (formerly type VIIC). This six-type classification, known as the Villefranche nomenclature, is still commonly used. The types are distinguished by their signs and symptoms, their underlying genetic causes, and their patterns of inheritance. Since 1997, several additional forms of the condition have been described. These additional forms appear to be rare, affecting a small number of families, and most have not been well characterized.

Fungal infections in bone marrow transplant patients. PURPOSE OF REVIEW: Invasive fungal infections have become the leading infectious cause of death in recipients of hematopoietic cell transplantation. Several factors have led to a renaissance in the study of invasive fungal infections.

Hypothyroidism during pregnancy is treated with synthetic thyroid hormone, thyroxine (T4). Postpartum thyroiditis—inflammation of the thyroid gland—causes a brief period of hyperthyroidism, often followed by hypothyroidism that usually goes away within a year. Sometimes the hypothyroidism is permanent.

Asthma and COPD

What Happens When You're In a Coma?

The average human digestive tract is home to as many as 1,000 species of microorganisms. Most of them are harmless -- or even helpful -- under normal circumstances. But when something upsets the balance of these organisms in your gut, otherwise harmless bacteria can grow out of control and make you sick. One of the worst offenders is a bacterium called Clostridium difficile(C. difficile, or C. diff). As the bacteria overgrow they release toxins that attack the lining of the intestines, causing a condition called Clostridium difficilecolitis.

Experts do not know the exact cause of Zollinger-Ellison syndrome. About 25 to 30 percent of gastrinomas are caused by an inherited genetic disorder called multiple endocrine neoplasia type 1 (MEN1). MEN1 causes hormone-releasing tumors in the endocrine glands and the duodenum.

Acute intermittent porphyria (AIP) is a rare autosomal dominant metabolic disorder affecting the production of heme, the oxygen-binding prosthetic group of hemoglobin. It is characterized by a deficiency of the enzyme porphobilinogen deaminase.

Uncomplicated acute otitis media (AOM) should be treated empirically with amoxicillin. Recurrent AOM should raise concern for beta-lactamase resistance and warrants treatment with amoxicillin-clavulanic acid. Ototopical medications are unnecessary, even if there is tympanic membrane perforation.