omentum A sheet of fat that is covered by peritoneum. The greater omentum is attached to the bottom edge of the stomach and hangs down in front of the intestines. Its other edge is attached to the transverse colon. The lesser omentum is attached to the top edge of the stomach and extends to the…
omega-3 fatty acids A class of fatty acids found in fish oils, especially salmon and other cold-water fish, that acts to lower the levels of total cholesterol and LDL cholesterol in the blood. Omega-3 fish oil is considered a neutraceutical, a food that provides health benefits. Eating fish has been reported to protect against age-related…
Ollier’s disease See multiple enchondromatosis.
oliguria Less urination than normal.
oligospermia Fewer sperm than usual. Azospermia, by contrast, means absolutely no sperm at all.
oligosaccharidosis One of a group of inherited metabolic disorders that are similar to the mucopolysaccharidoses. These conditions include aspartylglycosaminuria (AGU), fucosidosis, mannosidosis, and multiple sulfatase deficiency. Symptoms generally include deterioration of the nervous system. No treatment is available.
oligopeptide A molecule that is composed of a few amino acids linked to one another.
oligonucleotide probe A short sequence of nucleotides that are synthesized to match a specific region of DNA or RNA then used as a molecular probe to detect the specific DNA or RNA sequence.
oligonucleotide A short DNA molecule that is composed of relatively few nucleotide bases.
oligomenorrhea Less menstrual blood flow than usual.
oligohydramnios Too little amniotic fluid. The opposite of polyhydramnios: Too much amniotic fluid.
oligodendroglioma A rare, slow-growing brain tumor that begins in cells called oligodendrocytes, which provide support and nourishment for cells that transmit nerve impulses. Also known as oligodendroglial tumor.