Ethics of Research involving animals
Glossary H-O
Hepatocyte: The main specialised cells of the liver.
Hepatotoxicity: Damage to the hepatocytes of the liver.
Histopathology: Cellular changes in tissues caused by disease.
Hormone: A molecule secreted by an endocrine gland into the blood that regulates the development and/or activities of specific cells in the body.
Humane endpoint: See Endpoint.
Hybrid: A hybrid animal or plant is the product of a genetic cross between two different breeds, lines or species; species hybrids such as mules are often sterile. Hybrid cells can be produced in culture by fusing two different cell types.
Hybrid view: A view that combines two different viewpoints.
Immunodeficient: An animal with a poorly functioning
immune system.
Inbred strains: Organisms that are almost genetically identical, which are usually produced by repeated rounds of inbreeding.
Incubation period (of a disease): The period between exposure to an infection and the appearance of the first symptoms.
Intravenous (i.v.): Administered into a vein.
Invasive: A procedure that involves the introduction of instruments into the body.
Invertebrates: Animals without a backbone.
In vitro: A process or procedure in a test tube or culture dish (‘in glass’).
In vivo: A process or procedure in a living animal (‘in life’).
Kantian: Approach of the German philosopher Kant. Kant affirms the existence of an absolute moral law, the categorical imperative. See deontology.
Knock-out: Removal or inactivation of a gene.
Knock-in: Replacement of one gene by another (often modified) gene.
Locus: (pl. loci) The site of a specific gene on a
chromosome.
Lymphocyte: A type of white blood cell that is responsible for adaptive immune responses.
Metabolic/metabolism: The basic chemical processes that occur in a living organism or cell.
Microelectrode: A very small electrode, often used to study electrical characteristics of living cells and tissues.
Mitochondria: Organelles (specialised microscopic structures within a cell) involved in energy production in cells.
Multigene families: Groups of related genes. Multigene families are believed to have arisen by duplication and variation of a single ancestral gene.
Mutagen: A substance capable of causing a mutation.
Mutation (or mutagenesis): The chemical modification of a
DNA sequence that has the potential to lead to a change in the function of a gene. Mutations may be caused either by mistakes during the copying of DNA during cell division or by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or, most commonly, of no consequence. They are only inherited if they occur in cells that make eggs or sperm.
Neural: Of or relating to the nervous system.
Neuron: A nerve cell.
Neurotransmitter: A chemical substance released from a nerve cell that signals to another nerve or muscle cell at a specialised contact site called a synapse.
Nociception: The registration, transmission and processing of painful stimuli by the nervous system.
Nuclear transplantation: Transplantation of a nucleus from one cell into another cell from which the nucleus has been removed.
Nucleus: (pl. nuclei) A large, membrane-enclosed organelle in an eukaryotic cell, containing the chromosomes.
Nucleotide: The subunits from which DNA and RNA molecules are assembled. A nucleotide contains a base molecule (adenine, cytosine, guanine or thymine in DNA; adenine, cytocine, guanine or uracil in RNA), linked to a sugar molecule and phosphate groups. Specific sequencesof three nucleotides code for specific amino acids.
Nude mouse: A mutant mouse strain that arose spontaneously, which has no fur or thymus gland. Because it has no thymus, it is immunodeficient, and will readily accept foreign tissue grafts.
Old world monkey: A group of primates distinguished by their non-prehensile (incapable of grasping) tails.
Olfaction: The process of smelling.
Ontology: A branch of metaphysics dealing with the nature of being. The term is also used to describe the relationship between different terms in formal structures, or the principles underlying the organisation of systems such as databases.
Oocyte: An immature germ cell that matures into an egg.
Over-expression: Greater than normal production, for example, of a protein or RNA molecule from a gene.