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How We See
How We See samer kareem 3,134 Views • 3 years ago

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.

Ligation of Aneurysm in ArterioVenous Malformation
Ligation of Aneurysm in ArterioVenous Malformation Alicia Berger 7,259 Views • 3 years ago

Ligation of Aneurysm in ArterioVenous Malformation

Morning Erection
Morning Erection samer kareem 9,760 Views • 3 years ago

Morning erections have colloquially been termed as “morning wood” while scientifically it is called nocturnal penile tumescence. It is a normal and healthy physiological reaction and response that most men experience in their lives. Morning erections are really the ending of a series of erections that happen to men during the night. Healthy men can, on average, have anywhere between three to five erections in a full night of sleep, each of which lasts from 25-35 minutes.

Diabetic Neuropathy
Diabetic Neuropathy samer kareem 10,087 Views • 3 years ago

Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. High blood sugar (glucose) can injure nerve fibers throughout your body, but diabetic neuropathy most often damages nerves in your legs and feet. Depending on the affected nerves, symptoms of diabetic neuropathy can range from pain and numbness in your extremities to problems with your digestive system, urinary tract, blood vessels and heart. For some people, these symptoms are mild; for others, diabetic neuropathy can be painful, disabling and even fatal. Diabetic neuropathy is a common serious complication of diabetes. Yet you can often prevent diabetic neuropathy or slow its progress with tight blood sugar control and a healthy lifestyle.

Examination of Arms
Examination of Arms Surgeon 11,256 Views • 3 years ago

Examination of the arms

Diabetes Complications and Kidney Disease
Diabetes Complications and Kidney Disease samer kareem 8,045 Views • 3 years ago

Diabetes Complications and Kidney Disease

Polycystic Ovary Syndrome
Polycystic Ovary Syndrome samer kareem 18,003 Views • 3 years ago

Polycystic ovary syndrome is a common endocrine system disorder among women of reproductive age. Women with PCOS may have enlarged ovaries that contain small collections of fluid — called follicles — located in each ovary as seen during an ultrasound exam. Infrequent or prolonged menstrual periods, excess hair growth, acne, and obesity can all occur in women with polycystic ovary syndrome. In adolescents, infrequent or absent menstruation may raise suspicion for the condition. The exact cause of polycystic ovary syndrome is unknown. Early diagnosis and treatment along with weight loss may reduce the risk of long-term complications, such as type 2 diabetes and heart disease.

Endoscopic Nasal Polypectomy
Endoscopic Nasal Polypectomy DrHouse 20,301 Views • 3 years ago

Endoscopic Nasal Polypectomy Using a Stryker "Hummer"

Cholecystectomy with Hysterectomy
Cholecystectomy with Hysterectomy Mohamed 15,021 Views • 3 years ago

A good case comprising of laparoscopic cholecystectomy with lap. assisted vaginal hysterectomy done simultaneously

Porcelain Gallbladder
Porcelain Gallbladder samer kareem 6,662 Views • 3 years ago

Porcelain gallbladder is a condition characterized by calcium salt deposits in the wall of a chronically inflamed gallbladder. The calcifications can be thin or faintly visible, or may be amorphous, patchy, and thick. The gallbladder is generally large, but its size can vary considerably. Most porcelain gallbladders are associated with gallstones. A plain radiograph generally detects these, but computed tomography (CT) has a higher specificity; therefore, a CT scan is performed to confirm the diagnosis. Due to their high risk of gallbladder carcinoma, all patients with porcelain gallbladder should have an elective cholecystectomy.

Doctor Giving Heart Massage During Surgery
Doctor Giving Heart Massage During Surgery samer kareem 35,740 Views • 3 years ago

cardiac massage intermittent compression of the heart by pressure applied either over the sternum (closed cardiac massage) or directly to the heart through an opening in the chest wall (open cardiac massage). simple massage in the nursing interventions classification, a nursing intervention defined as stimulation of the skin and underlying tissues with varying degrees of hand pressure to decrease pain, produce relaxation, and/or improve circulation.

Histology of Sympathetic Ganglion
Histology of Sympathetic Ganglion Mohamed 18,667 Views • 3 years ago

Histology of Sympathetic Ganglion

Kidney failure Treatment
Kidney failure Treatment s 2,322 Views • 3 years ago

Failing Kidneys and Different Treatment Options

Bone Movement During Childbirth and Delivery 3D
Bone Movement During Childbirth and Delivery 3D Alicia Berger 38,155 Views • 3 years ago

Bone Movement During Childbirth and Delivery 3D

Accident Animation | Workers Compensation: Falling Stuff
Accident Animation | Workers Compensation: Falling Stuff Landging 6,785 Views • 3 years ago

http://www.landging.com/accident-animation-workers-compensation-falling-stuff.html
This falling stuff accident animation demonstrates the injury covered by workers compensation program.

Guillain-Barré Syndrome
Guillain-Barré Syndrome samer kareem 3,023 Views • 3 years ago

Guillain-Barre (gee-YAH-buh-RAY) syndrome is a rare disorder in which your body's immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body. In its most severe form Guillain-Barre syndrome is a medical emergency. Most people with the condition must be hospitalized to receive treatment. The exact cause of Guillain-Barre syndrome is unknown. But it is often preceded by an infectious illness such as a respiratory infection or the stomach flu. There's no known cure for Guillain-Barre syndrome, but several treatments can ease symptoms and reduce the duration of the illness. Most people recover from Guillain-Barre syndrome, though some may experience lingering effects from it, such as weakness, numbness or fatigue.

Nervous System Animation
Nervous System Animation Landging 4,391 Views • 3 years ago

http://www.landging.com/nervous-system-animation.html Human body nervous system, 3D MOA (Mechanism of Action) animation, designed for Beijing Natural History Museum.

Flu  Virus
Flu Virus samer kareem 2,275 Views • 3 years ago

There are two main types of influenza (flu) virus: Types A and B. The influenza A and B viruses that routinely spread in people (human influenza viruses) are responsible for seasonal flu epidemics each year. Influenza A viruses can be broken down into sub-types depending on the genes that make up the surface proteins. Over the course of a flu season, different types (A & B) and subtypes (influenza A) of influenza circulate and cause illness.

Renal biopsy
Renal biopsy samer kareem 8,317 Views • 3 years ago

A renal biopsy is a procedure used to extract kidney tissue for laboratory analysis. The word “renal” describes the kidneys. A renal biopsy is also called a kidney biopsy. The test helps your doctor identify the type of kidney disease you have, how severe it is, and the best treatment for it.

How Sperm Meets Egg
How Sperm Meets Egg samer kareem 10,774 Views • 3 years ago

Sperm Meets Egg: Weeks 1 to 3 of Pregnancy. Something magical is about to happen! Watch as the ovulation process occurs, and then millions of sperm swim upstream on a quest to fertilize an egg. ... The egg travels down the fallopian tube, pushed by tiny hairs and awaits the arrival or sperm.

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