Your Body.IN THE NEXT CENTURY, WILL YOUR BODY GROW ITS OWN SPARE PARTS? HEART TODAY: Surgeons replace damaged heart valves Heart valves Valves that regulate blood flow into and out of the heart chambers. Mentioned in: Heart Failure (which control blood flow) with plastic or metal valves, or valves taken from pigs, lambs, or other animals. TOMORROW: Scientists will sprout new heart valves from a patient's own cells. ORGANS TODAY: Researchers can grow small of pieces of human liver tissue but haven't developed the the technology to use this tissue for transplants. TOMORROW: Within 10 to 20 years, will routinely receive transplanted hearts livers, and kidneys--all grown from human tissue in the lab. NERVES TODAY: Doctors reconstruct nerves damaged by disease or injury using pig nerve cells cultivated in laboratories. The process of replacing human tissues with animal tissues is called xenotransplantation xen·o·trans·plan·ta·tion n. The surgical transfer of cells, tissues, or especially whole organs from one species to another. xenotransplantation (ZEE-no-trans-plan-TA-shun). TOMORROW: Artificial nerves will be made from synthetic material called polymers. LIMBS TODAY: Doctors replace legs and arms with prosthetic pros·thet·ic adj. 1. Serving as or relating to a prosthesis. 2. Of or relating to prosthetics. prosthetic serving as a substitute; pertaining to prostheses or to prosthetics. , or artificial, limbs. They attach fake limbs to the peripheral (puh-RIF-er-ul) nervous system, which connects the brain and spinal cord spinal cord, the part of the nervous system occupying the hollow interior (vertebral canal) of the series of vertebrae that form the spinal column, technically known as the vertebral column. to muscles that help move the new limb. TOMORROW: Doctors will use prosthetic limbs that actually feel sensation by connecting wires to the central nervous system (the brain and spinal cord). BONE AND CARTILAGE TODAY: Doctors inject hormones, chemicals that affect body functions, into fractured jaws and other bones to help them regenerate or regrow Re`grow´ v. i. & t. 1. To grow again. The snail had power to regrow them all [horns, tongue, etc.] - A. B. Buckley. Verb 1. . TOMORROW: The body will produce its own new bone and cartilage (connective tissue between bones). Surgically implanted plastic "scaffolds" will act as molds for bone and cartilage cells to grow on. As cells multiply, scaffolds will slowly dissolve. HAIR TODAY: People who lose their hair can opt for surgical hair or scalp transplants, but these are often unsuccessful--or unattractive. TOMORROW: Doctors will stimulate hair to regenerate using special growth proteins (substances used in many body functions, including hair growth). EYES TODAY: Doctors correct near- or farsightedness (vision defects) with laser surgery (using intense light beams instead of a scalpel). TOMORROW: Doctors will surgically implant permanent lenses to correct vision, removing the need for contact lenses or glasses. SKIN TODAY: Researchers manufacture replacement skin in 7.5 centimeter (3-inch) sheets, made from human cells and synthetic or manmade, substances. The new skin heals severe burns and other injuries. TOMORROW: The body grows new skin from stem cells stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastula typical of placental mammals; see embryo), which is very young (immature cells that haven't yet turned into blood, nerve, or other specialized cells). Stem cell stem cell In living organisms, an undifferentiated cell that can produce other cells that eventually make up specialized tissues and organs. There are two major types of stem cells, embryonic and adult. growth will be stimulated by growth hormones (chemicals that trigger body parts to grow). BLOOD VESSELS Blood vessels Tubular channels for blood transport, of which there are three principal types: arteries, capillaries, and veins. Only the larger arteries and veins in the body bear distinct names. TODAY: Researchers make use of pig cells and polymers (synthetic materials) to build new veins and arteries. But the human immune system immune system Cells, cell products, organs, and structures of the body involved in the detection and destruction of foreign invaders, such as bacteria, viruses, and cancer cells. Immunity is based on the system's ability to launch a defense against such invaders. often rejects the foreign cells. So patients must take anti-rejection drugs Anti-Rejection Drugs Definition Anti-rejection drugs are daily medications taken by organ transplant patients to prevent organ rejection. Purpose , which may have serious side effects. TOMORROW: New veins and arteries will grow directly from a patient's own cells to avoid immune-system rejection. DO YOU KNOW? The first animal-to-human organ transplants were performed: * in the Middle Ages * in the early 20th century * in 1995 This Issue's Answers p. 13: in the early 20th century |
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