Medical terms - Letter T

Thiamine deficiency, infantile

See: Infantile beriberi

Thiazolidinedione

(Pronounced THIGH-ah-ZO-li-deen-DYE-own.) A class of drugs for type 2 diabetes that lower the blood sugar by increasing the sensitivity of cells to insulin. Insulin can then move glucose from the blood into cells for…

Thigh

The thigh extends from the hip to the knee. The thigh has only one bone, the femur which is the largest bone in the human body. The thigh is the thick part of the leg. This is reflected in the word 'thigh' which comes…

Thigh bone

The thigh bone in anatomy is called the 'femur.' Whichever term you care to use -- thigh bone or femur, it is the bone in the leg that extends from the hip to the knee. The thigh bone/femur constitutes the upper leg…

Thimerosal

A mercury-containing preservative used in some vaccines and other products since the 1930's. No harmful effects were reported from thimerosal at doses used in vaccines, except for minor local reactions like redness and…

ThinPrep Pap test

A modified Pap test technique designed to reduce some of the technical problems inherent in the traditional type of Pap smear. In the traditional Pap test, cell samples are obtained from the vagina, cervix, and cervical…

Thioxanthene

One of a group of drugs with antipsychotic activity which act by blocking postsynaptic (after-the-nerve) receptors for dopamine (a chemical that nerves use to communicate with one another) in the brain. Examples…

Third and fourth pharyngeal pouch syndrome

See: DiGeorge syndrome

Third cranial nerve

Third degree burn

See: Burn, third degree

Third stage of labor

The part of labor from the birth of the baby until the placenta (afterbirth) and fetal membranes are delivered. The third stage of labor is also called the placental stage

Third ventricle

>Lateral ventricles: The lateral ventricles are in the cerebral hemispheres, one in each hemisphere. Each lateral ventricle consists of a triangular central body and four horns. The lateral ventricles communicate with…

Thomas Campion

See: Campion, Thomas

Thomas Sydenham

See: Sydenham, Thomas

Thomas, Lewis

(1913-1993) American physician, biologist, and eminent essayist. Thomas graduated from Princeton University and Harvard Medical School. He was dean of the medical schools at Yale and New York University and chief…

Thoracentesis

Removal of fluid in the pleura through a needle

Thoraces

Plural of thorax.

Thoracic

Pertaining to the chest

Thoracic aneurysm

A local widening and bulging of a vessel (an aneurysm) within the thorax (chest). See: Aortic aneurysm. An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm…

Thoracic aorta

The thoracic aorta is a section of the aorta, the largest artery in the body, within the chest. Specifically, the thoracic aorta is that part of the aorta that starts after the arch of the aorta and runs down to the…

Thoracic cage

The structure formed by the thoracic vertebrae and ribs, the sternum (breastbone), and the costal cartilages (that attach the ribs to the sternum). A cage is an enclosure made of 'open work' that usually houses animals…

Thoracic duct

A vascular structure which recirculates lymph into the blood stream. It begins in the abdomen and tracks alongside the aorta and esophagus to eventually join with the left brachiocephalic vein.

Thoracic outlet syndrome

Thoracic outlet syndrome: A condition due to compromise of blood vessels or nerve fibers between the armpit (axilla) and base of the neck, usually due to compression of nerves or blood vessels between the neck and…

Thoracic vertebrae

The 12 thoracic vertebrae are situated between the cervical (neck) vertebrae and the lumbar vertebrae. The thoracic vertebrae are represented by the symbols T1 through T12. The thoracic vertebrae provide attachment for…

Thoracolumbosacral orthosis (TLSO)

One of the two main types of braces used to correct the lateral (sideways) curve of the spine in scoliosis. Patients can wear this brace to correct spinal curves whose apex is at or below the eighth thoracic vertebra…

Thoracotomy

An operation to open the chest

Thorax

The area of the body located between the neck and the abdomen that contains the lungs, the heart and part of the aorta. The walls of the thorax are supported by the dorsal vertebrae, the ribs, and the sternum. The…

Thoraxes

Plural of thorax

Thorn test

An early test for Addison's disease. The test is named for Dr. George W. Thorn who devised it. See: Thorn, George W.

Thorn, George W.

American endocrinologist (1906-2004) who was a pioneer in the use of cortisone for treating Addison's disease; a member of the medical team responsible for the first successful kidney transplant; and editor-in-chief of…

Thr

Threonine. See also: Amino acid symbols

Three day fever

See: Sandfly fever

Three-day fever

See: Sandfly fever

Threonine

An amino acid, one of the 20 building blocks of protein. A dietary essential amino acid, threonine is necessary for optimal growth in childhood but its exact roles in metabolism are unknown. Symbol: Thr

Thrive, failure to (FTT)

Refers to a child whose physical growth is significantly less than that of peers. There is no official consensus on what constitutes FTT. It usually refers to a child whose growth is below the 3rd or 5th percentiles for…

Throat

The throat is the anterior (front) portion of the neck beginning at the back of the mouth, consisting anatomically of the pharynx and larynx. The throat contains the trachea and a portion of the esophagus

Thrombectomy

Procedure to remove a clot (a thrombus)

Thrombi

Just the plural of thrombus. See: Thrombus

Thrombin

A key clot promoter, thrombin is an enzyme that presides over the conversion of a substance called fibrinogen to fibrin, the right stuff for a clot

Thrombinogen

Better known today as prothrombin, a coagulation (clotting) factor needed for the normal clotting of blood. There is a cascade of biochemical events that leads to the formation of the final clot. In this cascade…

Thrombocyte

A platelet. Crucial to normal blood clotting. Although platelets are sometimes classed as blood cells, they are not. They are fragments of a large cell called a megakaryocyte (literally, a large cell).

Thrombocythemia

An abnormally high number of platelets in the blood. Also known as thrombocytosis.

Thrombocytopenia, heparin-induced

See TAR syndrome.

Thrombocytopenia-absent radius syndrome

See TAR syndrome

Thrombocytopenic purpura, acute

See thrombocythemia.

Thrombocytosis

See thrombocythemia

Thromboembolism

Formation in a blood vessel of a clot (thrombus) that breaks loose and is carried by the blood stream to plug another vessel. The clot may plug a vessel in the lungs (pulmonary embolism), brain (stroke)…

Thrombolytic agent

A drug that is able to dissolve a clot (thrombus) and reopen an artery or vein. Thrombolytic agents may be used to treat a heart attack, stroke, deep vein thrombosis (clot in a deep leg vein), pulmonary embolism, and…

Thrombophilia

The tendency to form blood clots (thrombosis). The clots can break off, travel through the bloodstream and lodge in any artery of the body (thromboembolism) and impair the normal circulation within these tissues…

Thrombophlebitis

Inflammation of a vein that occurs when a blood clot forms