Top videos
A bone marrow biopsy removes a small amount of bone and a small amount of fluid and cells from inside the bone (bone marrow). A bone marrow aspiration removes only the marrow. These tests are often done to find the reason for many blood disorders and may be used to find out if cancer or infection has spread to the bone marrow. Bone marrow aspiration removes a small amount of bone marrow fluid and cells through a needle put into a bone. The bone marrow fluid and cells are checked for problems with any of the blood cells made in the bone marrow. Cells can be checked for chromosome problems. Cultures can also be done to look for infection. A bone marrow biopsy removes bone with the marrow inside to look at under a microscope. The aspiration (taking fluid) is usually done first, and then the biopsy.
Knee osteotomy is commonly used to realign your knee structure if you have arthritic damage on only one side of your knee. The goal is to shift your body weight off the damaged area to the other side of your knee, where the cartilage is still healthy. When surgeons remove a wedge of your shinbone from underneath the healthy side of your knee, the shinbone and thighbone can bend away from the damaged cartilage. Imagine the hinges on a door. When the door is shut, the hinges are flush against the wall. As the door swings open, one side of the door remains pressed against the wall as space opens up on the other side. Removing just a small wedge of bone can "swing" your knee open, pressing the healthy tissue together as space opens up between the thighbone and shinbone on the damaged side so that the arthritic surfaces do not rub against each other. Osteotomy is also used as an alternative treatment to total knee replacement in younger and active patients. Because prosthetic knees may wear out over time, an osteotomy procedure can enable younger, active osteoarthritis patients to continue using the healthy portion of their knee. The procedure can delay the need for a total knee replacement for up to ten years.
Ca2+ binds with the membrane of the synaptic vesicles, which causes the vesicles to break and release the neurotransmitter into the synaptic cleft. After the neurotransmitters are released, they diffuse across the synaptic cleft and interact with receptors on the postsynaptic membrane. When the action potential reaches the presynaptic terminal, it provokes the release of a small quantity of neurotransmitter molecules, which bind to chemical receptor molecules located in the membrane of another neuron, the postsynaptic neuron, on the opposite side of the synaptic cleft.
Peristalsis, involuntary movements of the longitudinal and circular muscles, primarily in the digestive tract but occasionally in other hollow tubes of the body, that occur in progressive wavelike contractions. Peristaltic waves occur in the esophagus, stomach, and intestines.
Retinitis pigmentosa is a rare, inherited degenerative eye disease that causes severe vision impairment. Symptoms often begin in childhood. They include decreased vision at night or in low light and loss of side vision (tunnel vision). There's no effective treatment for this condition. Wearing sunglasses may help protect remaining vision.
An abdominal aortic aneurysm is an enlarged area in the lower part of the aorta, the major blood vessel that supplies blood to the body. The aorta, about the thickness of a garden hose, runs from your heart through the center of your chest and abdomen. Because the aorta is the body's main supplier of blood, a ruptured abdominal aortic aneurysm can cause life-threatening bleeding. Depending on the size and the rate at which your abdominal aortic aneurysm is growing, treatment may vary from watchful waiting to emergency surgery. Once an abdominal aortic aneurysm is found, doctors will closely monitor it so that surgery can be planned if it's necessary. Emergency surgery for a ruptured abdominal aortic aneurysm can be risky.