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Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs. Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder. You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.
Wernicke's aphasia is a neurological disorder typically caused by stroke. It affects the Wernicke's region in the brain's left hemisphere which is reasoned to be responsible for processing of meaning, especially as it relates to verbal communication, hence the problems with speech witnessed in these patients
The ureter can become obstructed due to conditions such as kidney stones, tumors, infection, or blood clots. When this happens, physicians can use image guidance to place stents or tubes in the ureter to restore the flow of urine to the bladder. A ureteral stent is a thin, flexible tube threaded into the ureter.
-Tibial stress fractures are common in athletes and nonathletes who suddenly increase their physical activity. Clinical features include pain, localized tenderness, and swelling. Plain x-ray is <50% sensitive for stress fractures, especially in the first 2-3 weeks after the onset of symptoms. MRI is preferred over bone scan or ultrasound as it can show the fracture line that extends through the cortex into the medullary line. MRI can also identify ligament, muscle, and cartilage injuries. However, MRI findings may be persistently abnormal for up to 1 year after the stress fracture has healed.
Menorrhagia is the medical term for menstrual periods with abnormally heavy or prolonged bleeding. Although heavy menstrual bleeding is a common concern, most women don't experience blood loss severe enough to be defined as menorrhagia. With menorrhagia, you can't maintain your usual activities when you have your period because you have so much blood loss and cramping. If you dread your period because you have such heavy menstrual bleeding, talk with your doctor. There are many effective treatments for menorrhagia.
At each level of the spine, there is a disc space in the front and paired facet joints in the back. Working together, these structures define a motion segment (Fig. 1A). Back pain may result when injury or degenerative changes allow abnormal movement of the vertebrae to rub against one another, known as an unstable motion segment (Fig. 1B). Two vertebrae need to be fused to stop the motion at one segment. For example, an L4-L5 fusion is a one-level spinal fusion (Fig. 1C). A two-level fusion joins three vertebrae together and so on.
Both lower extremities must be evaluated to determine the presence or extent of any disease and to ascertain the pulse status of the patient. The feet are examined for signs of peripheral vascular disease and the anterior and posterior tibial pulses are palpated. Because an intact arch can supply retrograde flow to the major vessels of the foot, it can be helpful to put pressure on the anterior tibial artery when detecting the presence of a posterior tibial pulse and visa-versa. This "modified Allen's test" may detect proximal vessel obstruction masked by an intact foot arch. The need for preoperative angiography in young, healthy patients with a normal physical examination has been hotly debated. Our tendency has been to obtain preoperative angiograms as a guide. Although rare, we have seen lower extremities with a dominant peroneal artery nourishing the foot and distal anterior and posterior vessels, contraindicating sacrifice of the peroneal artery. MRI or CT angiography can also be used in many circumstances.
Central venous catheter. Diagram showing a tunneled central line inserted into the right subclavian vein. A central venous catheter (CVC), also known as a central line, central venous line, or central venous access catheter, is a catheter placed into a large vein.