- T -
T Lymphocyte, T Cell
The most common type of lymphocyte, itself divided into at least three subpopulations on the basis of function -- cytotoxic, or killer T lymphocytes, helper T lymphocytes, and suppressor T lymphocytes. T cells play a cardinal role in regulating the immune system.
Tachycardia
Rapid heart beat.
Tachypnea
Rapid breathing.
Tamoxifen
An anticancer drug used in hormone therapy to block the effects of estrogen.
Tandem repeat sequences
Multiple copies of the same base sequence on a chromosome; used as a marker in physical mapping.
Taste
Sensation produced by a stimulus applied to the gustatory nerve endings in the tongue; the four tastes include: salt, sour, sweet, and bitter; some say there is a fifth taste described as savory.
Taste buds
Groups of cells located on the tongue that enable one to recognize different tastes.
Taste disorder
Inability to perceive different flavors.
Technetium bone scan
Radiological investigation to detect stress fractures.
Technology transfer
The process of converting scientific findings from research laboratories into useful products by the commercial sector.
Telemetry unit
A small transmitter with wires that attach ECG patches to the chest that is used to send information about the heart, via radio transmission, to healthcare professionals for evaluation.
Telomere
The ends of chromosomes. These specialized structures are involved in the replication and stability of linear DNA molecules. See DNA replication.
Temporal arteries
Vessels located over the temples on each side of the head that supply blood to part of the head.
Tendon
A cord that connects muscle to bone or other tissue.
Tendonitis
Inflammation of a tendon or of the tendon covering; usually caused by not just a single injury, but a series of small stresses that repeatedly aggravate the tendon.
Teratogens
Any agent that raises the incidence of congenital malformations.
Thallium stress test
A study in which radioactive potassium is carried by the blood; the progress is followed by x-ray pictures.
Thomas's test
Examination to detect a fixed hip deformity.
Thoracotomy
Surgery to view the lung (that may be used to confirm cancer), or for chest trauma (to detect the source of bleeding).
Throat disorders
Disorders or diseases of the larynx (voice box) or esophagus.
Thrombolysis
The breaking up of a blood clot.
Thrombolytic drugs
Medications used to dissolve blood clots.
Thrombosis
An abnormal condition in which a blood clot develops in the blood vessel or in the heart.
Thrombosis, deep-vein
Formation of blood clots in veins deep inside the legs.
Thrombus
A blood clot.
Thymine
A nitrogenous base, one member of the base pair A- T (adenine-thymine).
Thyroid
A two-lobed structure located in front of and on either side of the trachea, producing the hormone thryoxin; of or relating to the thyroid gland.
Thyroid-Stimulating Hormone
A hormone of the anterior pituitary gland that stimulates and regulates the development and secretory activity of the thyroid gland.
Thyroplasty (LARYNGEAL FRAMEWORK SURGERY)
Surgical technique to improve the voice by altering the cartilages of the larynx.
Thyrotoxicosis
Poisoning from hyperthyroidism.
Thyroxine (T4)
A hormone secreted by the thyroid gland which regulates metabolism.
Tibia
Shin bone.
Tinnitus
Sensation of a ringing, roaring, or buzzing sound in the ears or head; often associated with various forms of a hearing impairment.
Tissue
A group or layer of cells that together perform a specific function.
Tissue
Group or layer of cells that together perform specific functions.
Tissue plasminogen activator (TPA)
A medication used to dissolve blood clots.
Titer
The concentration of a substance in a solution, or the strength of such a substance detected by titration. In the current context, the term is most likely to refer to antibody titer, which is a measure of the concentration of specific antibodies to selected microbes that are circulating in an individual's bloodstream.
Tomography
From the Greek words 'to cut or section' (tomos) and 'to write' (graphein); in nuclear medicine, it is a method of separating interference from the area of interest by imaging a cut section of the object.
Tongue
Large muscle on the floor of the mouth that manipulates food for chewing and swallowing; the main organ of taste; assists in forming speech sounds.
Total gastrectomy
Complete removal of the stomach.
Total hysterectomy
The removal of the uterus, including the cervix; the fallopian tubes and the ovaries remain.
Total hysterectomy with bilateral salpingo-oophorectomy
The entire uterus, fallopian tubes, and the ovaries are surgically removed.
Tourette syndrome
Neurological disorder characterized by recurring movements and sounds (called tics).
Toxins
Poisons produced by certain animals, plants, or bacteria.
Tracheoesophageal fistula (TEF)
Condition that occurs when there is a gap between the upper and lower segments of the esophagus, in which food and saliva cannot pass through.
Trait
Any detectable phenotypic property of an organism.
Transcription
The process of copying information from DNA into new strands of messenger RNA (mRNA). The mRNA then carries this information to the cytoplasm, where it serves as the blueprint for the manufacture of a specific protein.
Transcutaneous electrical nerve stimulation (TENS)
A method of providing pain relief using electrical signals which are sent to the nerve endings.
Transduction
The transfer of bacterial genetic material from one bacterium to another using a phage as a vector.
Transesophageal echocardiography (TEE)
A diagnostic test that is used to measure the sound waves that bounce off of the heart.
Transfer RNA (TRNA)
A class of RNA having structures with triplet nucleotide sequences that are complementary to the triplet nucleotide coding sequences of mRNA. The role of tRNAs in protein synthesis is to bond with amino acids and transfer them to the ribosomes, where proteins are assembled according to the genetic code carried by mRNA.
Transferase
Enzymes that catalyze the transfer of functional groups between donor and acceptor molecules.
Transformation
A process by which the genetic material carried by an individual cell is altered by incorporation of exogenous DNA into its genome.
Transgenic organism
One into which a cloned genetic material has been experimentally transferred, a subset of these foreign gene express themselves in their offspring.
Transient ischemic attack (TIA)
A stroke-like event that lasts for a short period of time caused by a blocked blood vessel.
Translation
The process of turning instructions from mRNA, base by base, into chains of amino acids that then fold into proteins. This process takes place in the cytoplasm, on structures called ribosomes.
Translocation
A chromosome aberration which results in a change in position of a chromosomal segment within the genome, but does not change the total number of genes present.
Transplantation
Replacing a damaged organ with one from a donor.
Transrectal ultrasound of the prostate
A test using sound wave echoes to create an image of the prostate gland to visually inspect for abnormal conditions such as gland enlargement, nodules, penetration of tumor through capsule of the gland, and/or invasion of seminal vesicles; may also be use
Transurethral incision of the prostate (TUIP)
A procedure that widens the urethra by making some small cuts in the bladder neck, where the urethra joins the bladder, and in the prostate gland itself.
Transurethral resection of the prostate (TURP)
Surgery to remove part of the prostate gland that surrounds the urethra by using a small tool that is placed inside the prostate through the urethra; no incision is made using this method.
Transurethral surgery
Surgery in which no external incision is needed; the surgeon reaches the prostate by inserting an instrument through the urethra.
Transvaginal ultrasound (ULTRASONOGRAPHY)
An ultrasound test using a small instrument, called a transducer, that is placed in the vagina.
Transverse colon
Part of the colon that extends across the abdomen from right to left.
Trendelenburg gait
Intrinsic disorder of the abductors of the hip, due to either a weakness or an inhibition to function; hip abductors are unable to stabilize the hip, as body weight is transferred to the affected side, resulting in a pelvic drop or tilt towards the opposi
Tricuspid valve
The heart valve that controls blood flow from the right atrium into the right ventricle.
Trigger finger
An irritation of the digital sheath that surrounds the flexor tendons of the finger. When the tendon sheath becomes thickened or swollen, it pinches the tendon and prevents it from gliding smoothly. In some cases, the tendon catches and then suddenly rele
Trigger point
Hypersensitive area or site in muscle or connective tissue; usually associated with myofascial pain syndromes.
Trimester
A period of three months.
Triplet code
A code in which a given amino acid is specified by a set of three nucleotides.
tRNA
See transfer RNA.
Tube feeding
See enteral nutrition.
Tumor
An abnormal mass of tissue that grows more rapidly than normal, and continues to grow after the stimuli which initiated the new growth cease.
Tumor
A mass of excess tissue.
Tumor markers
Substances found in abnormal amounts in the blood, in other body fluids, or in tumor tissue of some patients with certain types of cancer.
Tumor suppressor gene
Genes that normally restrain cell growth but, when missing or inactivated by mutation, allow cells to grow uncontrolled.
Type 1 diabetes (INSULIN DEPENDENT DIABETES)
A condition in which the pancreas produces so little insulin that the body cannot use blood glucose as energy; which must be controlled with daily insulin injections.
Type 2 diabetes (NON-INSULIN DEPENDENT DIABETES)
A condition in which the pancreas produces so little insulin that the body cannot use the blood glucose as energy; can often be controlled through meal plans and physical activity plans, and diabetes pills or insulin.
Tyrosine
The amino acid from which dopamine is made.
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