Bioethics Terms
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Abortifacient: A chemical or other substance that induces abortion.
Abortion: In traditional clinical terminology, expulsion from the uterus of an embryo or fetus before it is viable (i.e., developmentally capable of independent existence). While spontaneous abortion (also known as âmiscarriageâ) is a common occurrence, the term âabortionâ is most often used to refer to induced abortionâthat is, abortion brought on intentionally via medical or surgical means (in contemporary usage it can refer to the removal of the fetus from the uterus after the point of probable viability as well). The practice of induced abortion is believed to predate recorded history, and some of the earliest medically related historical documents (e.g., Chinese, Egyptian, Greek, and Roman) refer to the practice. Debates about the morality of abortion also have an ancient pedigree and through the centuries have focused on such concerns as maternal well-being, openness to or control of fertility, beliefs about the actualized or potential personhood of the fetus, societal circumstances, and so on. In the United States, legal regulation (and then prohibition) of abortion practices began to be exercised by the states in the early nineteenth century, and by the 1880s most abortion procedures had been legally proscribed throughout the country. In 1973, however, the U.S. Supreme Court issued its Roe v. Wade decision, affirming womenâs reproductive liberty-based right to choose abortion in the first or second trimester of pregnancy; the stateâs interest in protecting maternal health, which would allow for regulation of how and where abortions are performed during the second trimester; and the stateâs interest in protecting the potentiality of human life, which would allow for legal proscription of abortion in the third trimester unless the pregnancy threatens the motherâs life or health. Abortion procedures currently practiced in the United States vary according to the stage of pregnancy. In the first trimester, abortion may be induced by surgical or medical means. Suction aspiration (also called âsuction curettageâ or âvacuum aspirationâ), the most widely used abortion method, involves suction removal of uterine contents through a flexible tube introduced via the cervix; it is usually performed between six and thirteen weeks of gestation (counting from the womanâs last menstrual period). Medical abortion, usually performed up until weeks seven to nine, involves use of drugs such as methotrexate or mifepristone (previously referred to as RU-486) to cause fetal death, combined with a contraction-inducing drug such as misoprostol. In the second trimester, dilation and curettage (D&C) and dilation and evacuation (D&E) involve dilation of the cervix followed by removal of fetus and placenta via surgical instruments or vacuum suction, or both. In another, nowrare form of second- and third-trimester abortion known as induction abortion, strong salt or other chemical solutions are introduced into the uterus, causing fetal death, after which uterine contractions are chemically induced. In recent years much public controversy has arisen about another form of late (after twenty-one weeksâ gestation) abortion called dilation and extraction (D&X or Intact D&X), also referred to as partial-birth abortion. This procedure involves cervical dilation followed by partial delivery of the intact fetus feet first; then a sharp instrument is inserted into the back of the fetusâs head and the brain is suctioned before delivery is completed. One other rarely employed abortion procedure is the hysterotomy abortion, in which the fetus is removed by making an incision in the pregnant womanâs abdomen and into the uterus; this is essentially an early Caesarian section delivery, albeit not resulting in live birth. (See also therapeutic abortion)
Acquired immune deficiency syndrome (AIDS): A syndrome in which the bodyâs immune system fails, leading to serious opportunistic infections. (See human immunodeficiency virus)
Active euthanasia: Sometimes referred to as âmercy killing.â Active euthanasia involves the use of drugs or other lethal means to cause the peaceful death of the individual being euthanized. (See euthanasia)
Act-utilitarianism: A form of moral reasoning in which judgment about the ârightâ thing to do is based upon a calculus of overall predicted good and bad consequences for each possible course of action in that particular situation. (See utilitarianism)
Adult stem cells: See stem cells
Advance directive [for health care]: A declaration, usually written, in which an individual describes the forms of medical treatment he wishes to receive, or designates another individual to make those treatment decisions on his behalf, should the directiveâs author lose decision-making capacity at some future date. In the United States, two major types of advance directive have gained widespread usage and legal recognition: the living will and the durable power of attorney for health care. A living will allows its author to define the types of medical treatment that he would choose to receive, as well as those that would be unwanted (and under what conditions), in the event the author becomes unable to choose or communicate those treatment choices in the future. In other words, the living will is a form of prospective consent to, or rejection of, specified forms of treatmentâquite often life-extending treatments. Conversely, a durable power of attorney for health care allows an author to designate a particular person or persons to act as his health care proxy for treatment choices, in the event that the author becomes incapable of forming or expressing those choices in the future. In other words, a durable power of attorney represents the authorâs prospective consent to those forms of treatment chosen on his behalf by the designated proxy or advocate.
AI (also AID and AIH): See artificial insemination
AIDS: See acquired immune deficiency syndrome; human immunodeficiency virus
Allele: One of a number of possible DNA (deoxyribonucleic acid) segments occupying a particular location on a chromosome, usually comprising a gene. For example, if hair color is determined by a particular DNA sequence (or gene) at a particular location on a particular chromosome, then the gene coding for brown hair and the gene coding for blonde hair are alleles of one another. Humans are diploid organisms whose somatic cells contain two full sets of chromosomes (one set from each parent); thus, each somatic cell has two alleles for each chromosome location (one on each paired chromosome). If both alleles at a given location are the same for each of the chromosomes in the pair, then the individual is said to be homozygous for that particular gene at that location. If the two alleles differ, then the individual is heterozygous for that gene.
Allocation: Distribution in the form of apportionment or allotment among persons or groups. At the broad social/political/economic level, macroallocation decisions apportion or allocate resources (usually funding) for particular kinds of goods or services and determine the methods of their distribution. For instance, federal funding for Medicare, the Veteranâs Administration (VA) hospital system, or the National Parks Service requires macroallocation decisions. Microallocation decisions apportion or allot among persons particular resources that are scarce (either naturally or because of previous macroallocation decisions). Distribution of scarce cadaver organs for transplant among the many potential recipients is an example of microallocation. The term ârationingâ is sometimes employed as a synonym for microallocation, although some commentators also use that term to refer to certain macroallocation decisions as well.
Allograft (homograft): Tissue or organ taken from a donor organism and transplanted into a recipient organism of the same species but of different genetic makeup, thus requiring suppression of the recipientâs immune system to prevent rejection of the graft. (See transplantation, organ and tissue)
Allopathic medicine: Term sometimes used to refer to conventional, traditional, or prevailing medical practice (in contrast to homeopathic or osteopathic medicine). The term was introduced in the mid-nineteenth century by C. F. S. Hahnemann, the founder of homeopathy, to distinguish that practice from the âusualâ practice of medicine at that time, which he termed âallopathy.â
Amniocentesis: A technique for prenatal diagnosis performed by inserting a hollow needle through the pregnant womanâs abdomen into the uterus and withdrawing a sample of fluid from the amniotic sac surrounding the fetus. The sample fluid, which also contains loosed fetal cells, can be tested to diagnose many fetal characteristics and conditions, such as gender, fetal lung development, chromosomal abnormalities (e.g., Down syndrome), inherited metabolic disorders (e.g., Tay-Sachs disease or Lesch-Nyhan syndrome), neural tube defects (e.g., spina bifida, anencephaly), and suspected problems such as infection or maternalâfetal Rh incompatibility. Amniocentesis is the most widely used method of prenatal diagnosis.
Anemia: A condition (with many causes) in which the bodyâs blood contains fewer than normal red blood cells or the red blood cells contain insufficient oxygen-carrying hemoglobin molecules.
Anencephaly: A condition caused by failure of the forward end of the neural tube to fully close, so that the infant is born without a forebrain (or cerebral hemispheres) and with remaining brain tissue often not covered by skull or skin. (See neural tube defect)
Aneuploidy: The condition of having more or less than the normal diploid number of chromosomes in the cell nucleus (in humans, twenty-three pairs of autosomal chromosomes and two sex chromosomesâalso called euploidy). Aneuploidy is the most frequently observed form of cytogenetic abnormality. In monosomy, one of a pair of chromosomes is missing. So, for example, âmonosomy 12â would mean that only one chromosome 12 is present in the nucleus of each cell, or, as in Turnerâs syndrome, only one sex chromosome is present. In trisomy, three chromosomes of a particular type are present, as in Down syndrome (Trisomy 21), Edwardâs syndrome (Trisomy 18), Patauâs syndrome (Trisomy 13), Klinefelterâs syndrome (XXY), or XYY syndrome. In tetraploidy, four chromosomes of a particular type would be present. (Trisomies and tetraploidies would both be polyploid conditions.) Chromosomal aneuploidies may lead to prenatal or early infant mortality or may cause birth defects, infertility, mental retardation, or other genetic syndromes. A majority of prenatal diagnostic procedures are chosen and performed to detect chromosomal aneuploidies.
Animation: Literally, the process of taking on life, or becoming alive. In the history of Western philosophy and theology (especially since Aristotle), however, the term âanimationâ (together with the roughly synonymous terms âhominizationâ and âensoulmentâ) has often been used to refer to the process within human embryology in which the product of conception takes on a rational soul and thus becomes a fully human being. Aristotle believed that the human embryo/fetus takes on human formâthat is, becomes âanimatedâ or âensouledââat forty days after conception (for the male) or eighty to ninety days after conception (for the female). This view, later reflected in the works of Christian theologians Augustine and Aquinas and apparently dominant in medieval Roman Catholic theology, has been termed delayed animation or mediate animation. In contrast, immediate animation/hominization refers to the belief that the human soul is present from the moment of conception. Theories of delayed animation/hominization have been expressed in the history of Islamic theology as well as Christian theology; however, more recent (late nineteenth and twentieth century) official teachings within both theological traditions have tended to reject the notion of delayed animation.
Antibodies: Proteins produced by the immune system that attach to and cause the neutralization of antigens that invade the body.
Antigen (or immunogen): A foreign molecule (pollen, for example) or a protein molecule on the surface of an infectious agent (bacteria or virus) that provokes a response from the bodyâs immune system. The presence of antigens elicits the production of protein antibodies that specifically attach to and deactivate or destroy the invasive antigens.
Apgar score: A test designed to measure and report aspects of a newborn infantâs physical condition and vital functions. Developed by anesthesiologist Virginia Apgar in 1952, the test represents an assessment of five physiological factors represented by the acronym APGAR: activity (muscle tone); pulse (heart rate); grimace (responsiveness or âreflex irritabilityâ); appearance (skin coloration); and respiration (breathing rate). Each of these five factors is scored on a scale of 0 to 2; thus a combined or total Apgar score ranges between 0 (immediate resuscitation needed) and 10 (the best possible condition). The five factors are usually scored at one minute after birth and then again at five minutes after birth. In cases of infant distress and low Apgar scores, the test may be repeated at 10, 15, or 20 minutes after birth. The Apgar score was not designed to predict a babyâs long-term outcome, health, behavior, or intellectual status; however, low scores measured at repeated intervals have been shown to be predictive of high rates of neonatal morbidity (illness) and mortality (death).
Applied ethics: A term referring to the application of ethical theory, ethical reasoning, or ethical perspective to particular areas of human life and activityâfor example, business ethics, legal ethics, health care ethics, or pastoral ethicsâor to particular problems, such as the moral issue of abortion or of warfare. The term âpractical ethicsâ is often used as a synonym for applied ethics. (See ethics)
Aretaic ethics (or aretology): See virtue ethics
ART: See assisted reproductive technology
Artificial insemination (AI): A procedure in which a manâs sperm is introduced into a womanâs vagina, uterus, or fallopian tubes by artificial means (rather than by sexual intercourse) to facilitate fertilization and pregnancy. In AIH (artificial insemination by husband), the womanâs partnerâs sperm is used, whereas sperm from a donor is used in AID (artificial insemination by donor). Types of AI also differ with regard to the location of insemination in the female reproductive tract: intrauterine (in the uterus); intracervical (in the cervical canal); intrafollicular (in the ovarian follicle); and intratubal (in the fallopian tubes).
Artificial womb/placenta: See ectogenesis
Assisted reproductive technology (ART): All treatments or procedures involving the handling or manipulation of both ova (eggs) and sperm for the purpose of helping a woman to become pregnant. (This definition, as employed by the U.S. Centers for Disease Control, would not include treatments or procedures in which only sperm are handled, as in artificial insemination, or procedures in which a womanâs production of ova is stimulated but without the intention of ova retrieval.) ART usually involves surgical removal of ova from a womanâs ovaries, combining them with sperm in the laboratory, and then returning them to the womanâs body (or another womanâs body). Six main types of ART are employed in the United States. The most common, in vitro fertilization (IVF), involves combining surgically retrieved ova with donated sperm in a laboratory dish, after which the fertilized embryo is transferred to the womanâs uterus through the cervix. In intracytoplasmic sperm injection (ICSI), a single sperm cell is injected into a retrieved ovum, after which it is placed in the womanâs uterus or fallopian tube. This is often a successful form of treatment in cases where infertility has been due to the manâs impaired sperm. Gamete intrafallopian transfer (GIFT) involves mixing ova and sperm together in a laboratory dish, then injecting the mixture via a laparoscope into the womanâs fallopian tubes where fertilization takes place. Zygote intrafallopian transfer (ZIFT) is like GIFT, but fertilization is allowed to happen in the laboratory dish, after w...