Dictionary

Body systems

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

T waveThe wave on an electrocardiogram that shows the heart's lower chambers recovering electrically after each beat.

tachycardiaA heart rate faster than normal; in an adult, more than 100 beats per minute.

tachypneaA breathing rate faster than normal, above 20 breaths per minute in an adult.

tardive dyskinesiaA movement disorder with repeated movements a person cannot control, most often of the face, lips and tongue.

Tay-Sachs diseaseAn inherited disease in which a missing enzyme lets a fatty substance build up and destroy nerve cells in the brain and spinal cord.

TBSATotal body surface area: the whole skin surface of the body, used to describe how much of it a burn covers.

telemetryContinuous heart rhythm monitoring in which a small device worn by the client sends the ECG signal to a central screen.

temporal lobeThe part of each side of the brain, above the ear, that handles hearing, memory and understanding language.

tendonA tough cord of tissue that attaches a muscle to a bone.

tension pneumothoraxA collapsed lung in which air keeps building up in the chest under pressure and presses on the heart and the other lung.

teratogenAnything a pregnant person is exposed to that can cause birth defects in the developing baby.

testisOne of the two male glands in the scrotum that make sperm and the hormone testosterone; plural testes.

testosteroneThe main male sex hormone, made mostly in the testes and in small amounts by the ovaries and adrenal glands.

tetanusA serious illness caused by a nerve toxin made by the bacterium Clostridium tetani.

tetanyInvoluntary muscle cramps and spasms that come from nerves firing too easily.

tetralogy of FallotA congenital heart defect made up of four problems in the structure of the heart.

thalamusA pair of egg-shaped masses deep in the brain that relay sensory signals to the cerebral cortex.

thalassemiaAn inherited blood disorder in which the body makes too little normal hemoglobin.

thermoregulationThe body's control of its own temperature, keeping it within a narrow normal range.

thighThe part of the leg between the hip and the knee.

third trimesterThe last part of pregnancy, from week 28 until birth.

thoracicRelating to the chest, or to the middle part of the spine.

thoraxThe chest: the part of the body between the neck and the abdomen.

thrillA buzzing or vibrating feeling felt with the fingertips over a blood vessel or the heart.

thrombinAn enzyme in the blood that turns fibrinogen into fibrin, the threads that hold a blood clot together.

thrombocytopeniaA blood platelet count below normal, under 150,000/mm3.

thromboembolismA blockage of a blood vessel by a blood clot that formed in one place and traveled through the blood to another.

thrombosisThe forming of a blood clot (a thrombus) inside a blood vessel or the heart.

thymusA small gland in the upper chest, behind the breastbone, where T cells (a kind of white blood cell) mature.

thyroidRelating to the thyroid gland in the neck or the hormones it makes; often used alone to mean the gland itself.

thyroid glandA butterfly-shaped gland at the front of the neck that makes hormones that control the body's metabolism.

thyroid hormoneA hormone made by the thyroid gland that controls how fast the body uses energy.

thyroidectomySurgery to remove all or part of the thyroid gland in the neck.

tibiaThe large inner bone of the lower leg, between the knee and the ankle; the shinbone.

tidal volumeThe amount of air moved in or out of the lungs with one normal breath.

tineaA fungal infection of the skin, hair or nails.

tinea capitisA fungal infection of the scalp and hair, also called ringworm of the scalp.

tinea corporisA fungal infection of the skin of the body, commonly called ringworm, although no worm is involved.

tinea crurisA fungal infection of the skin of the groin and inner thighs, often called jock itch.

tinea pedisA fungal infection of the skin of the feet, often called athlete's foot.

tissueA group of similar cells that work together to do a job in the body.

TNMTumor, Node, Metastasis: a system for describing how far a cancer has grown and spread.

tonic neck reflexA newborn reflex: when the baby's head turns toward one side, the arm and leg on that side stretch out while the opposite limbs bend.

tonsilOne of the masses of lymph tissue at the back of the throat that help fight germs entering the mouth and nose.

tonsillitisInflammation of the tonsils, the two lumps of lymph tissue at the back of the throat.

torsades de pointesA fast ventricular heart rhythm in which the QRS complexes on the ECG seem to twist around the baseline.

total knee replacementSurgery that replaces the worn surfaces of the knee joint with metal and plastic parts.

total parenteral nutritionComplete nutrition given as a liquid straight into a vein instead of through the digestive tract.

total thyroidectomySurgery to remove the whole thyroid gland.

toxic shock syndromeA rare, life-threatening illness caused by toxins from certain bacteria, mainly Staphylococcus aureus or group A streptococcus.