Dictionary

Body systems

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

osteopeniaBone density that is lower than normal but not low enough to be called osteoporosis.

osteoporosisA condition in which bones lose density and become thin, weak and easy to break.

ostomyA surgically made opening from an inside organ, such as the bowel or urinary tract, through the belly wall to the outside.

otitisInflammation of the ear.

otitis externaInflammation or infection of the outer ear canal, often called swimmer's ear.

otitis mediaInflammation or infection of the middle ear, the space behind the eardrum.

outflowThe flow of a fluid out of an organ, space or vessel.

ovarian cancerCancer that starts in the ovaries or in the nearby fallopian tubes.

ovaryOne of the two small female glands beside the uterus that hold eggs and make the hormones estrogen and progesterone.

overloadMore of something than the body can handle; in nursing, most often too much fluid in the circulation.

ovulationThe release of a mature egg from an ovary, usually once in each menstrual cycle.

ovumAn egg cell: the female reproductive cell that can join with a sperm to start a pregnancy.

oxygenated bloodBlood that has picked up oxygen in the lungs and is ready to carry it to the body.

oxygenationThe process of getting oxygen into the blood and delivering it to the body's tissues.

PACAn abbreviation with more than one meaning, most often premature atrial contraction or pulmonary artery catheter.

pacemakerA small device that sends electrical pulses to the heart to keep it beating at a set rate; also the heart's own natural rhythm center.

packed red blood cellA blood product made of red blood cells with most of the plasma removed, given by transfusion.

PADAn abbreviation that most often means peripheral artery disease, a narrowing of the arteries outside the heart and brain.

palmarHaving to do with the palm of the hand.

palmar grasp reflexA newborn reflex in which the baby's fingers close tightly around an object placed in the palm.

palpitationThe feeling of your own heartbeat as pounding, racing, fluttering or skipping.

pancreasA long, flat gland behind the stomach that makes digestive enzymes and the hormones insulin and glucagon.

pancreatitisInflammation of the pancreas, which may come on suddenly (acute) or last for years (chronic).

panic attackA sudden wave of intense fear that peaks within minutes.

papuleA small, solid, raised bump on the skin, less than 1 cm across, with no fluid inside.

paraThe number of pregnancies a person has carried to 20 weeks or more, whatever the outcome.

paralysisLoss of the ability to move a part of the body, and sometimes loss of feeling in it.

paralytic ileusA stop in the normal movement of the intestines that happens without anything physically blocking them.

paraplegiaParalysis of both legs and the lower part of the body.

parasympatheticRelating to the part of the autonomic nervous system that calms the body and supports "rest and digest" functions.

parasympathetic nervous systemThe part of the autonomic nervous system that calms the body, slows the heart and helps digestion during rest.

parathyroid glandOne of four small glands behind the thyroid that control the amount of calcium in the blood.

parathyroid hormoneA hormone from the parathyroid glands in the neck that raises the calcium level in the blood.

parenteral nutritionNutrition given as a liquid straight into a vein instead of through the digestive tract.

paresthesiaAn abnormal feeling in the skin, such as tingling, prickling or "pins and needles," with nothing touching it.

parietalRelating to the wall of a body cavity; also names a lobe of the brain and two bones of the skull.

parietal lobeThe part of the brain at the top and back of the head that processes touch, pain, temperature and the body's position in space.

Parkinson diseaseA slowly worsening brain disease in which the nerve cells that help control movement die off.

patent ductus arteriosusA heart defect in which the ductus arteriosus, a blood vessel between the aorta and pulmonary artery, stays open after birth.

patent foramen ovaleAn opening between the heart's two upper chambers that did not close after birth as it normally does.

pathologyThe study of disease and its causes and effects, or the disease changes found in a person or tissue.

pathophysiologyThe study of how normal body functions change when disease or injury is present.

PEAn abbreviation that most often means pulmonary embolism; it can also mean physical examination or pleural effusion.

pedicleA narrow stem or stalk that attaches a structure, such as a tumor or a skin flap, to the body.

pediculosisInfestation with lice, tiny wingless insects that live on the body and feed on blood.

pelvicHaving to do with the pelvis, the bowl-shaped ring of bones at the base of the spine, or the organs inside it.

pelvic inflammatory diseaseInfection of the female upper reproductive organs: the uterus, fallopian tubes and ovaries.

pelvisThe ring of bones at the base of the spine that joins the legs to the trunk, or the lower part of the trunk it encloses.

penetrationPassing into or through something, such as an object entering the body through the skin.