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|Word / term||Definition|
Very overweight. Conventionally defined as a body mass index (weight/height squared) greater than 30 in humans.
Obligate aerobe / anaerobe
Aerobe = An organism that requires oxygen for cellular respiration and cannot live without it. Anaerobe = An organism that cannot use oxygen and is poisoned by it.
Recurrent, persistent ideas, thoughts, images, or impulses that are egodystonic, i.e., are not experienced as voluntarily produced, but rather as ideas that invade consciousness. Obsessions are characteristic of obsessive compulsive disorder and may also be seen in schizophrenia.
An angle whose measure is greater than 90 degrees.
A triangle with an obtuse angle (an angle whose measure is greater than 90 degrees.)
Region in the back of the brain which processes visual information. Damage to this lobe can cause visual deficits.
The proportion of receptors to which a drug is bound. It may be calculated from the Hill-Langmuir adsorption isotherm:
Occupancy = ___________
K + [D]
where K is the dissociation constant for the drug and [D] is its concentration.
Occupational Therapy is the therapeutic use of self-care, work and play activities to increase independent function, enhance development and prevent disability; A therapy, treatment, or instructional support
A number in base 8.
Ocular dominance columns
A pattern of organization in primary visual cortex in terms of the dominance of inputs from the two eyes to a vertical column of neurons.
A function that satisfies the property that f(-x) = -f(x).
A whole number that is not divisible by 2.
A novel sterilization technique in which heat is generated within a food product due to its inherent resistance.
Ohmic ion channels
An ion channel through which ions flow equally well from one side of the membrane to the other. Ion channels are termed as ‘ohmic’ or ‘rectifier’ channels. In ohmic ion channels the ion flow is directly proportional to the voltage (I = Vm/R). In the second case the flow is not linearly related to the voltage as the ions flow more readily in one direction than the other. (see Ion channels or Rectifier ion channels)
Oligonucleotide ("oligo" means few)
A sequence of ~15-75 nucleotides (DNA or RNA) that is chemically synthesised from the 3’- to 5’-end by a cyclical process adding one nucleotide at a time.
Low in nutrients.
A heterotrophic animal that consumes both meat and plant material.
Omissions (in articulation)
An articulation error that occurs when not all of the sounds in a word are articulated.
A mutated gene in a tumor virus or in the genome of cancerous cells which, when transferred into other cells, can cause or promote a cell to undergo unregulated growth and division (i.e., to undergo cancer).
One Standard Test
A one standard test is an immunoassay test in which only one standard is assayed.
In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis . There is always an onset to a disease but never to the return to good health. The default setting is good health.
The embryonic development of an organism.
Collections of statements that define the relations between concepts and specify logical rules for reasoning about them.
A cell that gives rise by meiosis to an ovum.
A condition in which male and female gametes differ, such that a small, flagellated sperm fertilizes a large, nonmotile egg.
The process in the ovary that results in the production of female gametes.
Open circulatory system
An arrangement of internal transport in which blood bathes the organs directly and there is no distinction between blood and interstitial fluid.
An interval that does not contain both its endpoints.
Open-loop (or volitional) movements
Those movements triggered by a sensory cue or some internal desire to move.
Open reading frame
Any region of DNA or RNA where a protein could be encoded.
A type of associative learning that directly affects behavior in a natural context; also called trial-and-error learning.
The special software required to make a computer work.
Operator (in DNA)
A segment of DNA that interacts with a repressor protein to regulate the transcription of the structural genes of an operon .
A group of closely-linked genes coding for related proteins, and which appear to affect different steps in a single biosynthetic pathway and which apear to function as an integrated unit.
A form of spasm in which the head and the heels are bent backward and the body bowed forward.
An infection caused by germs that are not usually capable of causing infection in normal people, but can do so given certain changes (opportunity) in the immune system.
Species characterized by high reproduction rates, rapid development, early reproduction, small body size, and uncertain adult survival.
The covert display of underlying aggression by patterns of obstinate, but generally passive behavior.
An immune response in which the binding of antibodies to the surface of a microbe facilitates phagocytosis of the microbe by a macrophage.
either of a pair of second cranial nerves; transmits visual data from retina to brain.
Optical frequency comb
A precision tool for measuring frequencies of light; the frequency spectrum of a stabilized mode-locked laser consisting of hundreds of thousands of sharp lines of different colors (frequencies) that resemble the teeth of a comb.
Optical frequency synthesis
Control of the frequency comb produced with a mode-locked laser to produce a desired optical frequency.
Optical pulse synthesis
The use of two phase-locked-mode-locked femtosecond lasers to produce a new, coherent pulse with larger amplitude than the individual laser outputs.
A tightly focused beam of light capable of holding particles stable in three dimensions; optical tweezers.
A focused laser beam that can manipulate micron-sized objects in solution.
An instrument that is or uses a electrical-to-optical or optical-to-electrical transducer.
An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D.
A painful inflammation of the testicles and can lead to hypogonadism.
Where touch to the mouth is unpleasant.
Oral Polio Vaccine (OPV)
An immunization that protects children against polio.
In the current model of atomic structure, the volume of space surrounding the atomic nucleus in which an electron will be found 90 percent of the time.
A taxonomic grouping of related, similar families; the category below class and above family.An intermediate level of taxonomic classification containing one or more Families forming a subgroup of a Class.
A set of two numbers in which the order has an agreed upon meaning. Such as the cartesian coordinates (x, y), where it is agreed that the first coordinate represents the horizontal position, and the second coordinate represents the vertical position.
The second coordinate of a cartesian ordered pair.
Describes something that stimulates the intake of food. Hence anorexigenic = inhibits food intake.
A specialized center of body function composed of several different types of tissues.
Pertaining to, or derived from, biological material.
A plant gene in which a mutation causes a floral organ to develop in the wrong location.
Any living entity.
Organ of Corti
A structure within the inner ear (the cochlea) of the vertebrate ear.
One of several subcellular formed bodies in eukaryotic cells, with a specialized function, suspended in the cytoplasm. Membrane-bound structures in a eukaryotic cell that partitions the cell into regions which carry out different cellular functions, e.g., mitochondria, endoplasmic reticulum, lysosomes.
Pertaining to (1) organisms or living things generally, or (2) compounds formed by living organisms, or (3) the chemistry of compounds containing carbon.
The study of carbon compounds (organic compounds).
A chemical comound containing the element carbon and usually synthesized by cells.
plant and animal residues, or substances made by living organisms. All are based upon carbon compounds.
An individual living thing, such as a plant, animal or micro-organism (bacterium, fungus, protest). The individual member of a species; can be a single cell or a multicellular organism. Organisms are the biological unit of reproduction and while cells of single cell organism are autonomous (bacteria, archaea), individual cells of multicellular organisms (fungi, plants, animals) are not.
An early period of rapid embryonic development in which the organs take form from the primary germ layers.
Subjective impressions obtained using the human senses.
Rhythmic, involuntary contractions of certain reproductive structures in both sexes during the human sexual response cycle.
Awareness of one's environment and/or situation, along with the ability to use this information appropriately in a functional setting.
Orientation selective columns
A pattern of organization in primary visual cortex in terms of the preferred stimulus orientation to a vertical column of neurons.
In anatomy: The attachment of muscle (by means of a tendon) to the stationary bone.
Origin of replication
A specific sequence of bases in a nucleic acid molecule to which the enzymes responsible for replicating the nucleic acid bind to initiate the copying process.
Oropharyngeal airway (see also Nasopharyngeal airway)
An artificial airway that is inserted into the mouth and separates the tongue from the posterior pharynx
The point in a triangle where the three altitudes intersect.
The term ortholog is used to indicate an evolutionary related gene existing in two or more different organism. Orthologous genes have a high degree of similarity or sequence identity (see similarity). Orthology is a important way of assessing an organisms evolutionary history. For instance, some two thirds or all human genes have orthologs in the fruit fly Drosophila melanogaster. Humans share 99% of their genes with chimpanzee. Thus the degree of orthology correlates with the evolutionary relatedness between organisms (see also paralogs).
The branch of medicine devoted to the study and treatment of the skeletal system, its joints, muscles and associated structures. The branch of surgery broadly concerned with the skeletal system (bones). Orthopedics is how this field of surgery is listed under Physicians & Surgeons in the telephone Yellow Pages in Jacksonville, Florida. This spelling is quite common today. But it is incorrect, erroneous, flat out wrong. Orthopedics would relate the term to the foot because in Latin pedis means foot. Orthopaedics is not merely old-fashioned. It is the correct spelling. What was meant by the term orthopaedics when it was devised goes back to its roots: ortho-, straight + the Greek paes, child = the practice, literally, of straightening the child. If the child had a crooked spine ( scoliosis ), it was the job of the orthopaedist to straighten the child, not just the child's foot. That is why there is no American Academy of Orthopedic Surgery but there is an American Academy of Orthopaedic Surgery. And that is also why orthopaedists look after broken bones.
A condition in which a person is able to breathe most comfortably only in the upright position
Splint or brace designed to improve function or provide stability. An orthopedic appliance used to support, align, prevent or correct deformities or to improve the functioning of movable parts.
Oscillating magnetic fields
Magnetic fields generated with electromagnets of alternating current. The intensity varies periodically according to the frequency and type of wave in the magnet.
An animal that does not actively adjust its internal osmolarity because it is isotonic with its environment.
Adaptations to control the water balance in organisms living in hypertonic, hypotonic, or terrestrial environments.
An animal whose body fluids have a different osmolarity than the environment.
Tendency for fluids to mix, or become equally diffused, when in contact.
The diffusion of water from a region of low solute concentration to one of high solute concentration, through a selectively-permeable membrane. Diffusion of water across a semi-permeable barrier such as a cell membrane, from high water potential (concentration) (i.e.,a region of low-solute concentration) to lower water potential (concentration) (i.e., a region of low-water/high-solute concentration).
The tendency of water to move across a selectively permeable membrane into a solution. It is determined by measuring the pressure required to stop the osmotic movement of water into the solution.
A measure of the tendency of a solution to take up water when separated from pure water by a selectively permeable membrane.
A form of nutrition in which soluble compounds are taken up by the organism, either by pinocytosis or by mechanisms capable of transporting one or a few molecules at a time (membrane pumps).
Ossicles or Ossicular chain
In Vertebrates, the three small bones (malleus, incus, and stapes, or hammer, anvil, and stirrup) that are moved by the vibrations of the eardrum (in response to sound generally) and transmit these eardrum vinrations through the middle ear cavity to the inner ear. In Echinoderms, small calcareous plates forming the skeleton.
A type of arthritis caused by inflammation, breakdown, and eventual loss of cartilage in the joints. Also known as degenerative arthritis.
Refers to any structure that facilitates the formation of bone structure. Commonly used to describe the properties of various types of bone grafts and bone graft substitutes.
Osteogenesis imperfecta (OI)
Genetic disorder that is also characterized by easily fractured bones.
Any substance that stimulates bone formation. Bone morphogenetic proteins are osteoinductive.
The diminishing of bone density, typically related to aging and menopause in women.
Taking out part or all of a bone, or cutting into or through bone.
Surgical construction of an artificial opening (stoma) for external fistulization of a duct or vessel by insertion of a tube with or without a supportive stent.
The process of creating bone, that is of transforming cartilage (or fibrous tissue) into bone.
Excessive fluid, inflammation, and/or infection in the middle ear, caused by an inability to drain out through the eustachian tube.
A condition associated with diseases of the inner ear, characterized by destruction of the capsular bone in the middle ear and growth of a weblike bone that attaches to the stapes. May result in hearing disorders.
An instrument that allows seeing down the ear canal to see the ear drum and the external ear canal.
Drugs that can be poisonous to or have a deleterious effect on the
the place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body.
A species or group of species that is closely related to the group of species being studied, but clearly not as closely related as any study-group members are to each other. In a cladistic analysis, any taxon used to help resolve the polarity of characters, and which is hypothesized to be less closely related to each of the taxa under consideration than any are to each other.
The cyclic recurrence of the follicular phase, ovulation, and the luteal phase in the mammalian ovary, regulated by hormones.
A developing oocyte and the specialized cells surrounding it; located near the surface of the ovary; following ovulation, forms the corpus luteum.
A female in which the ovaries have been removed
(1) In flowers, the portion of a carpel in which the egg-containing ovules develop. (2) In animals, the structure that produces female gametes and reproductive hormones
Conventionally defined as a body mass index (weight/height squared) greater than 25.
A tube passing from the ovary to the vagina in invertebrates or to the uterus in vertebrates.
Referring to a type of development in which young hatch from eggs that are retained in the mother's uterus.
The deposition of eggs by the mother into a host or the environment.
A tubular organ that is used for oviposition, i. e., the laying of eggs.
The release of an egg from ovaries. In humans, an ovarian follicle releases an egg during each menstrual cycle.
A structure that develops in the plant ovary and contains the female gametophyte.
Ovum (Plural = Ova)
The female gamete; the haploid, unfertilized egg, which is usually a relatively large, nonmotile cell.
Chemical reaction involving the addition or combination of oxygen with another material.
to combine with oxygen.
The production of ATP using energy derived from the redox reactions of an electron transport chain.
A state in which the chemical balance is shifted towards an abundance of molecules that ‘oxidise’. That is, they are prone to donate electrons to other atoms and molecules.
The electron acceptor in a redox reaction.
A device that separates oxygen from room air, supplying up to 95% oxygen at low flow rates.
In muscle, the cumulative deficit of oxygen that develops during strenuous exercise when the supply of oxygen is inadequate for the demand. Then ATP is produced anaerobically by glycolysis, and the resulting pyruvic acid is converted to lactic acid, which is subsequently metabolized when adequate oxygen is available.
The need for molecular oxygen to meet the needs of biological and chemical processes in water.Even though very little oxygen will dissolve in water, it is extremely important in biological and chemical processes.
An isotope of oxygen that blocks ultra-violet radiation. Normally found in the stratosphere