Dictionary

Body systems

Anatomy and the conditions of each body system, from the heart and lungs to the skin.

impactedFirmly packed or wedged in place so it cannot move or pass normally.

impetigoA contagious bacterial skin infection, most common in young children.

implantationThe attachment of a fertilized egg to the lining of the uterus, the start of a pregnancy.

impulseAn electrical signal that travels along a nerve or through the heart muscle; also, a sudden urge to act.

in vitro fertilizationA fertility treatment in which eggs are joined with sperm in a lab and an embryo is then placed in the uterus.

inactivateTo make something, such as an enzyme, drug, hormone or germ, stop working.

incontinenceLoss of control over the bladder or bowel, so urine or stool leaks out without the person meaning it to.

increased intracranial pressurePressure inside the skull that has risen above the normal range.

indurationAn area of tissue that has become firm or hard, felt by touch.

infancyThe first year of life, from birth to about 12 months of age.

infantA baby from birth to 1 year of age.

infarctionDeath of an area of tissue (an infarct) because its blood supply has been cut off.

inferiorLower, or below; nearer the feet.

inferior vena cavaThe large vein that carries blood from the lower body back to the right atrium of the heart.

infertilityNot being able to become pregnant after a year of regular sex without birth control, or after six months for women over 35.

inflammationThe body's protective response to injury or infection, with redness, heat, swelling, pain and sometimes loss of function.

inflammatory bowel diseaseA group of long-term diseases, mainly Crohn disease and ulcerative colitis, in which the lining of the digestive tract becomes inflamed.

inflammatory responseThe body's protective reaction to injury or infection, which brings blood, fluid and white cells to the area.

influenzaAn infection of the nose, throat and lungs caused by influenza viruses; the flu.

ingestionTaking something into the body through the mouth, such as food, drink, a drug or a poison.

inguinalRelating to the groin, the fold where the thigh meets the lower abdomen.

inhalationBreathing in; also, a way of giving a drug as a mist or powder that is breathed into the lungs.

inner earThe deepest part of the ear, inside the skull bone, which holds the organs of hearing and balance.

inotropicChanging the force with which the heart muscle contracts; an inotropic drug is one that does this.

insomniaTrouble falling asleep, staying asleep or getting restful sleep.

insufficiencyA state in which an organ or part does not work well enough to meet the body's needs.

insulinA hormone made by the pancreas that lets the body's cells take in glucose, also made as a medicine.

insulin resistanceA state in which the body's cells respond poorly to insulin, so more insulin is needed to move glucose into them.

intakeWhat a person takes into the body, especially fluids or food, counted over a set time.

integumentaryRelating to the skin and the parts that grow from it, such as hair, nails and skin glands.

intellectual disabilityA condition that starts in childhood with limits in thinking and learning and in everyday living skills.

intercostalBetween the ribs.

intermittent auscultationChecking the baby's heart rate during labor at set times with a hand-held Doppler or fetoscope, instead of continuous monitoring.

internal jugular veinA large vein deep on each side of the neck that carries blood from the brain, face and neck back toward the heart.

interstitialRelating to the small spaces between cells or between the parts of a tissue or organ.

interstitial fluidThe fluid in the spaces between the body's cells, outside the blood vessels.

intervalThe time or space between two events, such as between two contractions in labor or between two waves on an ECG.

intestinalHaving to do with the intestines, the long tube that runs from the stomach to the anus.

intestineThe long tube of the digestive tract between the stomach and the anus, made up of the small and large intestine.

intimate partner violencePhysical, sexual or emotional harm, stalking or control by a current or former partner or spouse.

intoxicationA state in which alcohol, a drug or a poison changes how a person thinks, acts or how the body works.

intracellular fluidThe fluid inside the body's cells.

intracranialInside the skull.

intracranial pressureThe pressure inside the skull, made by the brain, the blood and the fluid around the brain.

intrauterineInside the uterus.

intrauterine deviceA small T-shaped device that a health care provider places inside the uterus to prevent pregnancy.

intrauterine growth restrictionSlower than expected growth of a fetus in the uterus, with an estimated weight below the 10th percentile for its age.

intrinsic factorA protein made by the stomach lining that the body needs in order to absorb vitamin B12 from food.

intussusceptionA condition in which one part of the intestine slides into the part next to it, like a telescope.

inversionA turning inward or upside down; for the foot, turning the sole in toward the other foot.