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Epigenetic
Epigenetic Something that affects a cell, organ or individual without directly affecting its DNA. An epigenetic change may indirectly influence the expression of the genome.
RELATED TERMS--------------------------------------
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
Organ
A structural unit of an animal or plant that serves a specific function.
DNA
Deoxyribo-Nucleic acid. DNA molecules carry the genetic information necessary for the organization and functioning of most living cells and control the inheritance of characteristics.
Epigenetic
Something that affects a cell, organ or individual without directly affecting its DNA. An epigenetic change may indirectly influence the expression of the genome.
Genome
The complete genetic material of an organism.
SIMILAR TERMS--------------------------------------
Epigastrium
The part of the abdominal wall above the umbilicus (belly button). The hypogastrium is the part of the abdominal wall below the umbilicus. The abdominal wall can thus be divided into upper and lower halves. Or it can be further divided into quadrants by also drawing a vertical line through the umbilicus.
Epigenesis
Originally from the Greek "epi" (on, upon, on top of) and "genesis" (origin); the theory that the embryo is not preformed in the ovum or the sperm, but that it develops gradually by the successive formation of new parts. The concept has been extended to other areas of medicine, with different shades of meaning. Some of the other meanings are as follows: 1. Any change in an organism that is due to outside influences rather than to genetically determined ones. 2. The occurrence of secondary symptoms as a result of disease. 3. Developmental factors, and specifically the gene-environment interactions, that contribute to development. 4. The appearance of new functions that are not predictable on the basis of knowledge of the part-processes that have been combined. 5. The appearance of specific features at each stage of development, such as the different goals and risks that Erikson described for the eight stages of human life (trust vs. mistrust, autonomy vs. doubt, etc.). The life cycle theory adheres to the epigenetic principle in that each stage of development is characterized by crises or challenges that must be satisfactorily resolved if development is to proceed normally.
Epigenetic effects
Changes in gene expression that occur without changing the DNA sequence of a gene; for example, in the epigenetic effect called genomic imprinting, chemical molecules called methyl groups attach to DNA and "turn off" the gene's expression.
Epigenetics
1. The study of heritable changes in gene function that occur without a change in the sequence of the DNA. 2. The study of certain processes that occur in embryonic development.
Epiglottis
The flap of cartilage at the base of the tongue that closes the trachea during swallowing to keep food or liquids from entering the airway.
Epiglottitis
An inflammation of the epiglottis, the flap of skin that hangs down the back of the throat and covers your windpipe when you swallow food, that can block the windpipe altogether, making breathing difficult. Generally caused by a bacterial infection that can be prevented by the Hib vaccine.
Epiglottitis, acute
A very rapidly progressive infection causing inflammation of the epiglottis (the flap that covers the trachea) and tissues around the epiglottis that may lead to abrupt blockage of the upper airway and death.
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Epidermolysis bullosa
One in a group of blistering skin conditions. The skin is so fragile in people with epidermolysis bullosa that even minor rubbing may cause blistering. At times, the person may not be aware of rubbing or injuring the skin even though blisters develop. In severe epidermolysis bullosa, blisters are not confined to the outer skin. They may develop inside the body, in such places as the linings of the mouth, esophagus, stomach, intestines, upper airway, bladder, and the genitals. Most forms of epidermolysis bullosa are evident at birth. This disorder can be both disabling and disfiguring, and some forms may lead to early death. The disease results when skin layers separate after minor trauma. Defects of several proteins within the skin are at fault.
Epidermolysis bullosa acquisita
A rare autoimmune skin disease with blisters. In epidermolysis bullosa acquisita (EBA) the body attacks its own anchoring fibrils with antibodies. The anchoring filaments (thread-like fibers) are structures that anchor the epidermis to the underlying basement membrane. The destruction of the anchoring fibrils leads to tissue separation and blistering in the upper part of the basement membrane.In some cases, EBA has occurred following drug therapy for another condition; in most cases, the cause is unknown.
Epidermolysis bullosa simplex
A blistering skin condition usually inherited as an autosomal dominant disease. The faulty genes are those that provide instructions for producing keratin, a fibrous protein in the top layer of skin. As a result, the skin splits in the epidermis, producing a blister.
Epidural anesthetic
An anesthetic agent injected into the epidural space, the space outside the dura -- the outermost, toughest, and most fibrous of the three membranes (meninges) covering the spinal cord -- in order to bath the spinal nerve roots in the anesthetic agent and numb the lower abdomen, pelvis, and legs.
Epigastrium
The part of the abdominal wall above the umbilicus (belly button). The hypogastrium is the part of the abdominal wall below the umbilicus. The abdominal wall can thus be divided into upper and lower halves. Or it can be further divided into quadrants by also drawing a vertical line through the umbilicus.
Epigenetic
Epigenetics
1. The study of heritable changes in gene function that occur without a change in the sequence of the DNA. 2. The study of certain processes that occur in embryonic development.
Epiglottitis, acute
A very rapidly progressive infection causing inflammation of the epiglottis (the flap that covers the trachea) and tissues around the epiglottis that may lead to abrupt blockage of the upper airway and death.
Epilation
Removal of body hair, including the hair root, by means of electrical device, tweezer, or wax. Epilation may be performed by a dermatologist, but is more commonly done for cosmetic purposes by a facial technologist or esthetician. After epilation the skin may be particularly sensitive. Also called depilation.
Epilepsy, Jacksonian
A brief alteration in movement, sensation or nerve function caused by abnormal electrical activity in a localized area of the brain. Seizures of this type typically cause no change in awareness or alertness. They are transient, fleeting, ephemeral. Jacksonian seizures are extremely varied and may involve, for example, apparently purposeful movements such as turning the head, eye movements, smacking the lips, mouth movements, drooling, rhythmic muscle contractions in a part of the body, abnormal numbness, tingling, and a crawling sensation over the skin. Jacksonian seizures are a form of epilepsy.
Epilepsy, juvenile myoclonic
A form of epilepsy that occurs between the ages of eight and 26, most commonly in the teenage years. It is characterized by jerking (myoclonic) movements of the arms and upper torso, without loss of consciousness. Seizures are most likely to occur while awakening from sleep. Many children with this disorder are sensitive to light (photosensitive), and may have myoclonic jerks or seizures when exposed to bright light. Diagnosis is by observation and by EEG. During a myoclonic seizure, polyspike-wave discharges over a normal EEG background are seen. Juvenile myoclonic epilepsy appears to be an inheritable genetic disorder, with the gene located on chromosome 6. Treatment is with anti- seizure medications.
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