Medical Terminology: Key Terms - All Chapters 2 Flashcards

The sense of balance

The sense of taste; Latin geusis means “taste”

The sense or perception of sound

The sense of smell; root osm/o means “smell”

The awareness of posture, movement, and changes in equilibrium; receptors are located in muscles, tendons, and joints

A sensory nerve ending or a specialized structure associated with a sensory nerve that responds to a stimulus

Pertaining to the sense of touch

The sense by which the shape, size, and color of objects are perceived by means of the light they give off

The tube that connects the middle ear with the nasopharynx and serves to equalize pressure between the outer and middle ear (root: salping/o); pharyngotympanic tube; originally called the eustachian tube

The brownish, waxlike secretion formed in the external ear canal to protect the ear and prevent infection; adjective: ceruminous

The coiled portion of the inner ear that contains the receptors for hearing (root: cochle/o)

The tube that connects the middle ear with the nasopharynx and serves to equalize pressure between the outer and middle ear (root: salping/o); auditory tube

Tube that extends from the pinna of the ear to the tympanic membrane; external auditory meatus

The middle ossicle of the ear

The inner ear, named for its complex structure, which resembles a maze

The ossicle of the middle ear that is in contact with the tympanic membrane and the incus

The small bones of the middle ear, the malleus, incus, and stapes

The projecting part of the outer ear; auricle

The three curved channels of the inner ear that hold receptors for equilibrium

The hearing receptor, which is located in the cochlea of the inner ear; organ of Corti

The ossicle that is in contact with the inner ear (root: staped, stapedi/o)

The membrane between the external auditory canal and the middle ear (tympanic cavity); the eardrum. It serves to transmit sound waves to the ossicles of the middle ear (root: myring/o, tympan/o)

The portion of the inner ear that is concerned with the sense of equilibrium; consists of the vestibule and the semicircular canals (root: vestibul/o)

The chamber in the inner ear that holds some of the receptors for equilibrium

The nerve that transmits impulses for hearing and equilibrium from the ear to the brain; eighth cranial nerve; auditory or acoustic nerve

A tumor of the eighth cranial nerve sheath; although benign, it can press on surrounding tissue and produce symptoms; also called a schwannoma or neurilemoma

Hearing impairment that results from blockage of sound transmission to the inner ear

A disease associated with increased fluid pressure in the inner ear and characterized by hearing loss, vertigo, and tinnitus

Inflammation of the external auditory canal; swimmer's ear

Inflammation of the middle ear with accumulation of serous (watery) or mucoid fluid

Formation of abnormal and sometimes hardened bony tissue in the ear. It usually occurs around the oval window and the footplate (base) of the stapes, causing immobilization of the stapes and progressive loss of hearing

Hearing impairment that results from damage to the inner ear, eighth cranial nerve, or auditory pathways in the brain

A sensation of noises, such as ringing or tinkling, in the ear

An illusion of movement, as of the body moving in space or the environment moving about the body; usually caused by disturbances in the vestibular apparatus. Used loosely to mean dizziness or lightheadedness

Surgical incision of the tympanic membrane; performed to drain the middle ear cavity or to insert a tube into the tympanic membrane for drainage

Surgical removal of the stapes; it may be combined with insertion of a prosthesis to correct otosclerosis

Pertaining to or perceived by the ear

A unit for measuring the relative intensity of sound

A unit for measuring the frequency (pitch) of sound

A small projection of the temporal bone behind the external auditory canal; it consists of loosely arranged bony material and small, air-filled cavities

A small muscle attached to the stapes. It contracts in the presence of a loud sound, producing the acoustic reflex

A cystlike mass containing cholesterol that is most common in the middle ear and mastoid region; a possible complication of chronic middle ear infection

Inflammation of the labyrinth of the ear (inner ear); otitis interna

Inflammation of the air cells of the mastoid process

Loss of hearing caused by aging; also presbyacusis

Measurement of hearing

A method for recording eye movements by means of electrical responses; such movements may reflect vestibular dysfunction

The branch of medicine that deals with diseases of the ear(s), nose, and throat (ENT); also called otolaryngology (OL)

Instrument for examining the ear

Test that measures hearing by comparing results of bone conduction and air conduction

A two-syllable word with equal stress on each syllable; used in hearing tests; examples are toothbrush, baseball, cowboy, pancake

Test for hearing loss that uses a vibrating tuning fork placed at the center of the head

Adjustment of the lens’s curvature to allow for vision at various distances

Fluid that fills the eye anterior to the lens

The dark, vascular, middle layer of the eye (roots: chori/o, choroid/o); part of the uvea (see below)

The muscular portion of the uvea that surrounds the lens and adjusts its shape for near and far vision (root: cycl/o)

A specialized cell in the retina that responds to light; cones have high visual acuity, function in bright light, and respond to colors

The mucous membrane that lines the eyelids and covers the eyeball’s anterior surface

Coordinated movement of the eyes toward fixation on the same point

The clear, anterior portion of the sclera (root: corne/o, kerat/o)

The organ of vision (root: opt/o, ocul/o, ophthalm/o)

The tiny depression in the retina that is the point of sharpest vision; fovea centralis, central fovea

The muscular colored ring between the lens and the cornea; regulates the amount of light that enters the eye by altering the size of the pupil at its center (roots: ir, irid/o, irit/o) plural: irides

Pertaining to tears (roots: lacrim/o, dacry/o)

The transparent, biconvex structure in the anterior portion of the eye that refracts light and functions in accommodation (roots: lent/i, phak/o)

A small spot or colored area; used alone to mean the yellowish spot in the retina that contains the fovea

The point where the optic nerve joins the retina; at this point there are no rods or cones; also called the blind spot or optic papilla

The bony cavity that contains the eyeball

An eyelid; a protective fold (upper or lower) that closes over the anterior surface of the eye (root: palpebr/o, blephar/o; adjective” palpebral; plural: palpebrae)

The opening at the center of the iris (root: pupill/o)

The bending of light rays as they pass through the eye to focus on a specific point on the retina; also the determination and correction of ocular refractive errors

The innermost, light-sensitive layer of the eye; contains the rods and cones, the specialized receptor cells for vision (root: retin/o)

A specialized cell in the retina of the eye that responds to light; rods have low visual acuity, function in dim light, and do not discriminate color

The tough, white, fibrous outermost layer of the eye; the white of the eye (root: scler/o)

The middle, vascular layer of the eye (root: uve/o); consists of the choroid, ciliary body, and iris

Sharpness of vision

The transparent jellylike mass that fills the main cavity of the eyeball; also called vitreous humor

Deterioration of the macula associated with aging; macular degeneration impairs central vision

An error of refraction caused by irregularity in the curvature of the cornea or lens

Opacity of the lens of the eye

Inflammation of the conjunctiva; pinkeye

Degenerative changes in the retina associated with diabetes mellitus

A disease of the eye caused by increased intraocular pressure that damages the optic disk and causes loss of vision. Usually results from faulty fluid drainage from the anterior portion of the eye

An error of refraction in which light rays focus behind the retina and objects can be seen clearly only when far from the eye; farsightedness; also called hypermetropia

An error of refraction in which light rays focus in front of the retina and objects can be seen clearly only when very close to the eye; nearsightedness

Severe conjunctivitis usually caused by infection with gonococcus during birth

Removal of a cataract by ultrasonic destruction and extraction of the lens

Changes in the eye that occur with age; the lens loses elasticity and the ability to accommodate for near vision

Separation of the retina from the underlying layer of the eye

An infection caused by Chlamydia trachomatis leading to inflammation and scarring of the cornea and conjunctiva; a common cause of blindness in underdeveloped countries

The angle at either end of the slit between the eyelids

A measurement unit for the refractive power of a lens

The normal condition of the eye in refraction, in which parallel light rays focus exactly on the retina

A bottom or base; the region farthest from the opening of a structure. The fundus of the eye is the back portion of the inside of the eyeball as seen with an ophthalmoscope

A sebaceous gland in the eyelid

The framework of dense connective tissue that gives shape to the eyelid; tarsal plate

A system of fibers that holds the lens in place; also called suspensory ligaments

A condition that occurs when visual acuity is not the same in the two eyes in children (prefix ambly means “dim”). Disuse of the poorer eye will result in blindness if not corrected. Also called “lazy eye”

Condition in which the two pupils (root: cor/o) are not of equal size

Drooping of the eyelid

A small mass on the eyelid resulting from inflammation and blockage of a meibomian gland

Small growths that appear as tiny yellowish spots beneath the retina of the eye; typically occur with age but also occur in certain abnormal conditions

A small moving object in the field of vision that originates in the vitreous body. Floaters appear as spots or threads and are caused by benign degenerative or embryonic deposits in the vitreous body that cast a shadow on the retina

Inflammation of a sebaceous gland of the eyelid; a sty

Conical protrusion of the corneal center

Abnormal contraction of the pupils (from Greek, meaning “diminution”)

Pronounced or abnormal dilation of the pupil

Night blindness. Inability to see well in dim light or at night (root: nyct/o); often due to lack of vitamin A, which is used to make the pigment needed for vision in dim light

Rapid, involuntary, rhythmic movements of the eyeball; may occur in neurologic diseases or disorders of the inner ear's vestibular apparatus

Swelling of the optic disk (papilla); choked disk

A small blister or nodule on the cornea or conjunctiva

A condition in which a cataractous lens has been removed and replaced with a plastic lens implant

Inflammation of the retina; causes include systemic disease, infection, hemorrhage, exposure to light

A hereditary chronic degenerative disease of the retina that begins in early childhood. There is atrophy of the optic nerve and clumping of pigment in the retina.

A malignant glioma of the retina; usually appears in early childhood and is sometimes hereditary; fatal if untreated, but current cure rates are high

An area of diminished vision within the visual field

A deviation of the eye in which the visual lines of each eye are not directed to the same object at the same time. Also called heterotropia or squint. The various forms are referred to as -tropias, with the direction of turning indicated by a prefix, such as esotropia (inward), exotropia (outward), hypertropia (upward), and hypotropia (downward). The suffix -phoria is also used, as in esophoria

Adhesion of parts, especially adhesion of the iris to the lens and cornea (plural: synechiae)

A soft, slightly raised, yellowish patch or nodule usually on the eyelids; occurs in the elderly; also called xanthelasma

Surgical division of a canthus

Instrument for incising the lens capsule

Study of the electrical response of the retina to light stimulation

Surgical removal of the eyeball

Examination of the angle between the cornea and the iris (anterior chamber angle) in which fluids drain out of the eye (root goni/o means “angle”)

An instrument for measuring the curvature of the cornea

A drug that causes dilation of the pupil

An instrument for determining the degree and kind of strabismus

An instrument used to determine refractive errors of the eye; also called a skiascope

An instrument for examining the eye under magnification

A chart printed with letters of decreasing size used to test visual acuity when viewed from a set distance; results reported as a fraction giving a subject's vision compared with normal vision at a distance of 20 feet

Suturing together of all or part of the upper and lower eyelids

An instrument used to measure fluid pressure in the eye

The largest artery. It receives blood from the left ventricle and branches to all parts of the body (root: aort/o)

The valve at the entrance to the aorta

The point of a cone-shaped structure (adjective, apical). The apex of the heart is formed by the left ventricle and is pointed toward the inferior and left

A vessel that carries blood away from the heart. All except the pulmonary and umbilical arteries carry oxygenated blood (root: arteri/o)

A small vessel that carries blood from the arteries into the capillaries (root: arteriol/o)

A small mass in the lower septum of the right atrium that passes impulses from the sinoatrial (SA) node toward the ventricles

A band of fibers that transmits impulses from the atrioventricular (AV) node to the top of the interventricular septum. It divides into the right and left bundle branches, which descend along the two sides of the septum; the bundle of His

A valve between the atrium and ventricle on the right and left sides of the heart. The right AV valve is the tricuspid valve; the left is the mitral valve

An entrance chamber, one of the two upper receiving chambers of the heart (root atri/o)

The force exerted by blood against the wall of a vessel

Branches of the AV bundle that divide to the right and left sides of the interventricular septum

A microscopic blood vessel through which materials are exchanged between the blood and the tissues

The part of the circulatory system that consists of the heart and the blood vessels

A change in electrical charge from the resting state in nerves or muscles

The relaxation phase of the heartbeat cycle; adjective, diastolic

Study of the electrical activity of the heart as detected by electrodes (leads) placed on the surface of the body. Also abbreviated EKG from the German electrokardiography

The thin membrane that lines the chambers of the heart and covers the valves

The thin outermost layer of the heart wall

Any sound produced as the heart functions normally

The muscular organ with four chambers that contracts rhythmically to propel blood through vessels to all parts of the body (root: cardi/o)

The number of times the heart contracts per minute; recorded as beats per minute (BPM)

Sounds produced as the heart functions. The two loudest sounds are produced by alternate closing of the valves and are designated S1 and S2

The large inferior vein that brings blood back to the right atrium of the heart from the lower body

The valve between the left atrium and the left ventricle; the mitral valve or bicuspid valve

The valve between the left atrium and the left ventricle; the left AV valve or bicuspid valve

The fibrous sac that surrounds the heart

The vessel that carries blood from the right side of the heart to the lungs

The system of vessels that carries blood from the right side of the heart to the lungs to be oxygenated and then back to the left side of the heart

The vessels that carry blood from the lungs to the left side of the heart

The valve at the entrance to the pulmonary artery

The wave of increased pressure produced in the vessels each time the ventricles contract

The terminal fibers of the conducting system of the heart. They carry impulses through the walls of the ventricles.

A return of electrical charge to the resting state in nerves or muscles

The valve between the right atrium and right ventricle; the tricuspid valve

A wall dividing two cavities, such as the chambers of the heart

Normal heart rhythm

A small mass in the upper part of the right atrium that initiates the impulse for each heartbeat; the pacemaker

An instrument for determining arterial blood pressure (root sphygm/o means “pulse”); blood pressure apparatus or cuff

The large superior vein that brings deoxygenated blood back to the right atrium from the upper body

The system of vessels that carries oxygenated blood from the left side of the heart to all tissues except the lungs and returns deoxygenated blood to the right side of the heart

The contraction phase of the heartbeat cycle; adjective: systolic

A structure that keeps fluid flowing in a forward direction (root: valv/o, valvul/o)

A vessel that carries blood back to the heart. All except the pulmonary and umbilical veins carry blood low in oxygen (root: ven/o, phleb/o)

A small cavity. One of the two lower pumping chambers of the heart (root: ventricul/o)

A small vessel that carries blood from the capillaries to the veins

A tube or duct to transport fluid (root: angi/o, vas/o, vascul/o)

A localized abnormal dilation of a blood vessel, usually an artery, caused by weakness of the vessel wall; may eventually burst

A feeling of constriction around the heart or pain that may radiate to the left arm or shoulder, usually brought on by exertion; caused by insufficient blood supply to the heart

Any abnormality in the rate or rhythm of the heartbeat (literally “without rhythm;” note doubled r). Also called dysrhythmia

Hardening (sclerosis) of the arteries, with loss of capacity and loss of elasticity, as from fatty deposits (plaque), deposit of calcium salts, or formation of scar tissue

The development of fatty, fibrous patches (plaques) in the lining of arteries, causing narrowing of the lumen and hardening of the vessel wall. The most common form of arteriosclerosis (hardening of the arteries). The root ather/o means “porridge” or “gruel”

A slow heart rate of less than 60 bpm

Sudden damage to the brain resulting from reduction of blood flow. Causes include atherosclerosis, embolism, thrombosis, or hemorrhage from a ruptured aneurysm; commonly called stroke

Enlargement of the ends of the fingers and toes caused by growth of the soft tissue around the nails. Seen in a variety of diseases in which there is poor peripheral circulation.

Localized narrowing on the aorta with restriction of blood flow

Protein produced during systemic inflammation, which may contribute to atherosclerosis; high CRP levels can indicate cardiovascular disease and its prognosis

Bluish discoloration of the skin caused by lack of oxygen

Thrombophlebitis involving the deep veins

Profuse sweating

An aneurysm in which blood enters the arterial wall and separates the layers. Usually involves the aorta

Disorder in serum lipid levels, which is an important factor in development of atherosclerosis. Includes hyperlipidemia (high lipids), hypercholesterolemia (high cholesterol), and hypertriglyceridemia (high triglycerides)

Difficult or labored breathing (-pnea)

Swelling of body tissues caused by the presence of excess fluid (see Fig. 6-4). Causes include cardiovascular disturbances, kidney failure, inflammation, and malnutrition

Obstruction of a blood vessel by a blood clot or other matter carried in the circulation

A mass carried in the circulation. Usually a blood clot, but also may be air, fat, bacteria, or other solid matter from within or from outside the body

Spontaneous, quivering, and ineffectual contraction of muscle fibers, as in the atria or the ventricles

An interference in the conduction system of the heart resulting in arrhythmia

A condition caused by the inability of the heart to maintain adequate circulation of blood

A varicose vein in the rectum

A condition of higher-than-normal blood pressure. Essential (primary, idiopathic) hypertension has no known cause

An area of localized necrosis (death) of tissue resulting from a blockage or a narrowing of the artery that supplies the area

Local deficiency of blood supply caused by obstruction of the circulation (root: hem/o)

An abnormal heart sound

Localized necrosis (death) of cardiac muscle tissue resulting from blockage or narrowing of the coronary artery that supplies that area. Myocardial infarction is usually caused by formation of a thrombus (clot) in a vessel

A closing off or obstruction, as of a vessel

Persistence of the ductus arteriosus after birth. The ductus arteriosus is a vessel that connects the pulmonary artery to the descending aorta in the fetus to bypass the lungs

Inflammation of a vein

A patch. With regard to the cardiovascular system, a deposit of fatty material and other substances on a vessel wall that impedes blood flow and may block the vessel. Atheromatous plaque

Damage to heart valves after infection with a type of streptococcus (group A hemolytic streptococcus). The antibodies produced in response to the infection produce valvular scarring, usually involving the mitral valve

An opening in the septum between the atria or ventricles; a common cause is persistence of the foramen ovale (for-Ā-men ō-VAL-ē), an opening between the atria that bypasses the lungs in fetal circulation

Circulatory failure resulting in an inadequate supply of blood to the tissues. Cardiogenic shock is caused by heart failure; hypovolemic shock is caused by a loss of blood volume; septic shock is caused by bacterial infection

A normal heart rhythm originating from the sinoatrial (SA) node

Constriction or narrowing of an opening

See cerebrovascular accident

A temporary loss of consciousness caused by inadequate blood flow to the brain; fainting

An abnormally rapid heart rate, usually over 100 bpm

Inflammation of a vein associated with formation of a blood clot

Development of a blood clot within a vessel

A blood clot that forms within a blood vessel (root: thromb/o)

A twisted and swollen vein resulting from breakdown of the valves, pooling of blood, and chronic dilatation of the vessel (root: varic/o); also called varix (VAR-iks) or varicosity (var-i-KOS-i-tē)

A procedure that reopens a narrowed vessel and restores blood flow. Commonly accomplished by surgically removing plaque, inflating a balloon within the vessel, or installing a device (stent) to keep the vessel open

A battery-operated device that generates electrical impulses to regulate the beating of the heart. It may be external or implanted, may be designed to respond to need, and may have the capacity to prevent tachycardia

Restoration of cardiac output and pulmonary ventilation after cardiac arrest using artificial respiration and chest compression or cardiac massage

Correction of an abnormal cardiac rhythm. May be accomplished pharmacologically, with antiarrhythmic drugs, or by application of electric current (see defibrillation)

Radiographic study of the coronary arteries after introduction of an opaque dye by means of a catheter

Surgical creation of a shunt to bypass a blocked coronary artery. The aorta is connected to a point past the obstruction with another vessel or a piece of another vessel, usually the left internal mammary artery or part of the leg's saphenous vein

Enzyme released in increased amounts from cardiac muscle cells following myocardial infarction (MI). Serum assays help diagnose MI and determine the extent of muscle damage

Use of an electronic device (defibrillator) to stop fibrillation by delivering a brief electric shock to the heart. The shock may be delivered to the surface of the chest, as by an automated external defibrillator (AED), or directly into the heart through wire leads, using an implantable cardioverter defibrillator (ICD)

A noninvasive method that uses ultrasound to visualize internal cardiac structures

A compound of protein with lipid. Lipoproteins are classified according to density as very low density (VLDL), low density (LDL), and high density (HDL). Relatively higher levels of HDLs have been correlated with health of the cardiovascular system

Dilatation of a sclerotic blood vessel by means of a balloon catheter inserted into the vessel and then inflated to flatten plaque against the artery wall

A small metal device in the shape of a coil or slotted tube that is placed inside an artery to keep the vessel open after balloon angioplasty

Evaluation of physical fitness by continuous ECG monitoring during exercise. In a thallium stress test, a radioactive isotope of thallium is administered to trace blood flow through the heart during exercise

A protein in muscle cells that regulates contraction. Increased serum levels, primarily in the forms TnT and TnI, indicate recent myocardial infarction (MI)

A small, fingerlike mass of lymphoid tissue attached to the first part of the large intestine

The thin plasmalike fluid that drains from the tissues and is transported in lymphatic vessels (root: lymph/o)

A small mass of lymphoid tissue along the path of a lymphatic vessel that filters lymph (root: lymphaden/o)

The system that drains fluid and proteins from the tissues and returns them to the bloodstream. This system also participates in immunity and aids in absorption of fats from the digestive tract

Aggregates of lymphoid tissue in the lining of the intestine

The lymphatic duct that drains fluid from the upper right side of the body

A large reddish-brown organ in the upper left region of the abdomen. It filters blood and destroys old red blood cells (root: splen/o)

The lymphatic duct that drains fluid from the upper left side of the body and all of the lower body/ left lymphatic duct

A gland in the upper part of the chest beneath the sternum. It functions in immunity (root: thym/o).

Small masses of lymphoid tissue located in regions of the throat (pharynx)

Inflammation and enlargement of lymph nodes, usually as a result of infection

Inflammation of lymphatic vessels as a result of bacterial infection. Appears as painful red streaks under the skin. (Also spelled lymphangitis)

Swelling of tissues with lymph caused by obstruction or excision of lymphatic vessels

Any neoplastic disease of lymphoid tissue

Pulse felt or heard over the apex of the heart. It is measured in the fifth left intercostal space (between the ribs) about 8 to 9 cm from the midline

The amount of blood pumped from the right or left ventricle per minute

Arterial sounds heard with a stethoscope during determination of blood pressure with a cuff

The passage of fluid, such as blood, through an organ or tissue

The anterior region over the heart and the lower part of the thorax; adjective, precordial

The difference between systolic and diastolic pressure

The amount of blood ejected by the left ventricle with each beat

Bearing down, as in childbirth or defecation, by attempting to exhale forcefully with the nose and throat closed. This action has an effect on the cardiovascular system

An abnormal sound heard in auscultation

Pathologic accumulation of fluid in the pericardial sac. May result from pericarditis or injury to the heart or great vessels.

A heartbeat that originates from some part of the heart other than the SA node

Premature contraction of the heart that occurs separately from the normal beat and originates from a part of the heart other than the SA node

Very rapid (200 to 300 bpm) but regular contractions, as in the atria or the ventricles

A condition of lower-than-normal blood pressure

Pain in a muscle during exercise caused by inadequate blood supply. The pain disappears with rest

Movement of the cusps of the mitral valve into the left atrium when the ventricles contract

Arteriosclerotic disease of the vessels, usually peripheral vessels

A sensation of abnormally rapid or irregular heartbeat

Edema that retains the impression of a finger pressed firmly into the skin

Potentially fatal collagen disease causing inflammation of small visceral arteries. Symptoms depend on the organ affected

A disorder characterized by abnormal constriction of peripheral vessels in the arms and legs on exposure to cold

A backward flow, such as the backflow of blood through a defective valve

Stoppage of normal flow, as of blood or urine. Blood stasis may lead to dermatitis and ulcer formation

Growth of bacteria in a heart or valves previously damaged by rheumatic fever

A combination of four congenital heart abnormalities: pulmonary artery stenosis, interventricular septal defect, displacement of the aorta to the right, and right ventricular hypertrophy

Inflammation and thrombus formation resulting in occlusion of small vessels, especially in the legs. Most common in young men and correlated with heavy smoking. Thrombotic occlusion of leg vessels may lead to gangrene of the feet. Patients show a hypersensitivity to tobacco. Also called Buerger disease

Irregular outgrowths of bacteria on the heart valves; associated with rheumatic fever

A cardiac arrhythmia consisting of tachycardia and a premature ventricular beat caused by an alternative conduction pathway

Passage of a catheter into the heart through a vessel to inject a contrast medium for imaging, diagnosing abnormalities, obtaining samples, or measuring pressure

Pressure in the superior vena cava

The photographic recording of fluoroscopic images of the heart and large vessels using motion picture techniques

Method for imaging the interior of arteries using computed tomography; uses less dye and is less invasive than standard angiography

An imaging method used to study the rate and pattern of blood flow

Imaging of the heart after injection of a radioactive isotope. The PYP (pyrophosphate) scan using technetium-99m (99mTc) is used to test for myocardial infarction because the isotope is taken up by damaged tissue. The MUGA (multigated acquisition) scan gives information on heart function

A portable device that can record up to 24 hours of an individual's ECG readings during normal activity

An amino acid in the blood that at higher-than-normal levels is associated with increased risk of cardiovascular disease

Technician who specializes in drawing blood

Electronic recording of heart sounds

Measurement of changes in the size of a part based on the amount of blood contained in or passing through it. Impedance plethysmography measures changes in electrical resistance and is used in the diagnosis of deep vein thrombosis

Pressure measured by a catheter in a branch of the pulmonary artery. It is an indirect measure of pressure in the left atrium

A cardiac catheter with a balloon at the tip that is used to measure pulmonary arterial pressure. It is flow-guided through a vein into the right side of the heart and then into the pulmonary artery transesophageal

Use of an ultrasound transducer placed endoscopically into the esophagus to obtain images of the heart

Simple fats that circulate in the bloodstream

X-ray study of the ventricles of the heart after introduction of an opaque dye by means of a catheter

Removal of atheromatous plaque from the lining of a vessel. May be done by open surgery or through the lumen of the vessel

Surgical incision of a scarred mitral valve to increase the size of the valve opening

Surgical removal of an embolus

A mechanical assist device that consists of an inflatable balloon pump inserted through the femoral artery into the thoracic aorta. It inflates during diastole to improve coronary circulation and deflates before systole to allow blood ejection from the heart

A pump that takes over the function of the left ventricle in delivering blood into the systemic circuit. These devices are used to assist patients awaiting heart transplantation or those who are recovering from heart failure

A drug that lowers blood pressure by blocking the formation in the blood of angiotensin II, a substance that normally acts to increase blood pressure

A drug that blocks tissue receptors for angiotensin II; angiotensin II receptor antagonist

A drug that regulates the rate and rhythm of the heartbeat

A white blood cell that does not have visible granules in its cytoplasm. Agranulocytes include lymphocytes and monocytes

A simple protein found in blood plasma

A protein produced in response to and interacting specifically with an antigen

A substance that induces the formation of an antibody

A lymphocyte that matures in lymphoid tissue and is active in producing antibodies; B lymphocyte (LIM-fō-sīt)

An immature neutrophil with a nucleus in the shape of a band; also called a stab cell. Band cell counts are used to trace infections and other diseases

A granular leukocyte that stains with basic dyes; active in allergic reactions

The fluid that circulates in the cardiovascular system (root: hem/o, hemat/o)

Blood clotting

Testing the compatibility of donor and recipient blood in preparation for a transfusion. Donor red cells are mixed with recipient serum, and red cells of the recipient are mixed with donor serum to look for an immunologic reaction. Similar tests are done on tissues before transplantation

A substance that separates into charged particles (ions) in solution; a salt. Term also applied to ions in body fluids

A granular leukocyte that stains with acidic dyes; active in allergic reactions and defense against parasites

A red blood cell (root: erythr/o, erythrocyt/o)

A hormone produced in the kidneys that stimulates red blood cell production in the bone marrow. This hormone is now made by genetic engineering for clinical use

The protein that forms a clot in the process of blood coagulation

The inactive precursor of fibrin

The cellular components of blood

The fraction of the blood plasma that contains antibodies; given for passive transfer of immunity

A white blood cell that has visible granules in its cytoplasm. Granulocytes include neutrophils, basophils, and eosinophils

The iron-containing pigment in red blood cells that transports oxygen

The stoppage of bleeding

The state of being protected against a specific disease (root: immun/o)

An antibody. Immunoglobulins fall into five classes, each abbreviated with a capital letter: IgG, IgM, IgA, IgD, IgE

A white blood cell (root: leuk/o, leukocyt/o)

An agranular leukocyte active in immunity (T cells and B cells); found in both the blood and in lymphoid tissue (root: lymph/o, lymphocyt/o)

A large bone marrow cell that fragments to release platelets

A phagocytic cell derived from a monocyte; usually located within the tissues. Macrophages process antigens for T cells

An agranular phagocytic leukocyte

A granular leukocyte that stains with acidic or basic dyes. The most numerous of the white blood cells. A type of phagocyte

The engulfing of foreign material by white blood cells

The liquid portion of the blood

A mature form of a B cell that produces antibodies

A formed element of the blood that is active in hemostasis; a thrombocyte (root: thrombocyt/o)

The fraction of the plasma that remains after blood coagulation; it is the equivalent of plasma without its clotting factors (plural: sera, serums)

A lymphocyte that matures in the thymus gland and attacks foreign cells directly; T lymphocyte

A blood platelet (root: thrombocyt/o)

Failure of the immune system caused by infection with HIV (human immunodeficiency virus). The virus infects certain T cells and thus interferes with immunity

A substance that causes an allergic response

Hypersensitivity

An exaggerated allergic reaction to a foreign substance (root phylaxis means. “protection”). It may lead to death caused by circulatory collapse, and respiratory distress if untreated. Also called anaphylaxis

A deficiency in the amount of hemoglobin in the blood; may result from blood loss, malnutrition, a hereditary defect, environmental factors, and other causes

A localized edema with large hives (wheals) similar to urticaria but involving deeper layers of the skin and subcutaneous tissue

Anemia caused by bone marrow failure resulting in deficient blood cell production, especially of red cells; pancytopenia

A condition in which the immune system produces antibodies against an individual's own tissues (prefix auto means “self”)

A form of thalassemia (hereditary anemia) which affects production of the β (beta) hemoglobin chain; thalassemia major

An allergic reaction involving T cells that takes at least 12 hours to develop. Examples are various types of contact dermatitis, such as poison ivy or poison oak; the tuberculin reaction (test for TB); and rejections of transplanted tissue

Widespread formation of clots in the microscopic vessels; may be followed by bleeding caused by depletion of clotting factors

A collection of blood under the skin caused by leakage from small vessels (root chym means “juice”)

The rupture of red blood cells and the release of hemoglobin (adjective: hemolytic)

A hereditary blood disease caused by lack of a clotting factor and resulting in abnormal bleeding

The virus that causes AIDS

A neoplastic disease of unknown cause that involves the lymph nodes, spleen, liver, and other tissues; characterized by the presence of giant Reed-Sternberg cells

An immunologic reaction to a substance that is harmless to most people; allergy

A congenital or acquired failure of the immune system to protect against disease

A substance produced in the stomach that aids in the absorption of vitamin B12, necessary for the manufacture of red blood cells. Lack of intrinsic factor causes pernicious anemia

Cancerous lesion of the skin and other tissues, seen most often in patients with AIDS

Malignant overgrowth of immature white blood cells; may be chronic or acute; may affect bone marrow (myelogenous leukemia) or lymphoid tissue (lymphocytic leukemia)

Any disease of the lymph nodes

A tumor of the blood-forming tissue in bone marrow

A widespread malignant disease of lymph nodes that involves lymphocytes. It differs from Hodgkin disease in that giant Reed-Sternberg cells are absent.

An abnormal chromosome found in the cells of most individuals with chronic granulocytic (myelogenous) leukemia

Anemia caused by failure of the stomach to produce intrinsic factor, a substance needed for the absorption of vitamin B12. This vitamin is required for the formation of erythrocytes.

Pinpoint, flat, purplish-red spots caused by bleeding within the skin or mucous membrane (singular: petechia)

A condition characterized by hemorrhages into the skin, mucous membranes, internal organs, and other tissues (from Greek word meaning “purple”). Thrombocytopenic purpura is caused by a deficiency of platelets

Anemia caused by inability to use available iron to manufacture hemoglobin. The excess iron precipitates in normoblasts (developing red blood cells)

An autoimmune disease involving dysfunction of the exocrine glands and affecting secretion of tears, saliva, and other body fluids. Deficiency leads to dry mouth, tooth decay, corneal damage, eye infections, and difficulty in swallowing

A hereditary anemia caused by the presence of abnormal hemoglobin. Red blood cells become sickle shaped and interfere with normal blood flow to the tissues. Most common in black populations of West African descent

Enlargement of the spleen

Inflammatory connective tissue disease affecting the skin and multiple organs. Patients are sensitive to light and may have a red butterfly-shaped rash over the nose and cheeks

A diffuse disease of connective tissue that may involve any system causing inflammation, degeneration, and fibrosis. Also called scleroderma because it causes thickening of the skin

A group of hereditary anemias mostly found in populations of Mediterranean descent (the name comes from the Greek word for “sea”)

A deficiency of thrombocytes (platelets) in the blood

A skin reaction consisting of round, raised eruptions (wheals) with itching; hives

See epinephrine

A count of the T cells that have the CD4 receptors for the AIDS virus (HIV). A count of less than 200/µL of blood signifies severe immunodeficiency.

A powerful stimulant produced by the adrenal gland and sympathetic nervous system. Activates the cardiovascular, respiratory, and other systems needed to meet stress. Used as a drug to treat severe allergic reactions and shock. Also called adrenaline

Blood counts of reticulocytes, a type of immature red blood cell; reticulocyte counts are useful in diagnosis to indicate the rate of erythrocyte formation

Giant cells that are characteristic of Hodgkin disease. They usually have two large nuclei and are surrounded by a halo

The clumping of cells or particles in the presence of specific antibodies

A pigment derived from the breakdown of hemoglobin. It is eliminated by the liver in bile

A group of plasma enzymes that interacts with antibodies

A small mass or body. A blood corpuscle is a blood cell

A primitive bone marrow cell that gives rise to all varieties of blood cells

A substance found throughout the body that inhibits blood coagulation; an anticoagulant

An enzyme that dissolves clots; also called fibrinolysin

The enzyme derived from prothrombin that converts fibrinogen to fibrin

A condition involving a decrease in the number of granulocytes in the blood; also called granulocytopenia

Increase in the number of red cells in the blood; may be normal, such as to compensate for life at high altitudes, or abnormal, such as in cases of pulmonary or cardiac disease

Congenital aplastic anemia that appears between birth and 10 years of age; may be hereditary or caused by damage before birth, as by a virus

An immunologic reaction of transplanted lymphocytes against tissues of the host; a common complication of bone marrow transplantation.

A form of leukemia in which cells have filaments, making them look “hairy”

A localized collection of blood, usually clotted, caused by a break in a blood vessel

Disease that results from incompatibility between the blood of a mother and her fetus, usually involving Rh factor. An Rh-negative mother produces antibody to an Rh-positive fetus that, in later pregnancies, will destroy the red cells of an Rh-positive fetus. The problem is usually avoided by treating the mother with antibodies to remove the Rh antigen; erythroblastosis fetalis

A condition involving the deposition of an iron-containing pigment (hemosiderin) mainly in the liver and the spleen. The pigment comes from hemoglobin released from disintegrated red blood cells

A clotting disorder caused by destruction of platelets that usually follows a viral illness. Causes petechiae and hemorrhages into the skin and mucous membranes

An acute infectious disease caused by Epstein–Barr virus (EBV). Characterized by fever, weakness, lymphadenopathy, hepatosplenomegaly, and atypical lymphocytes (resembling monocytes)

Disease that results from incompatibility between the blood of a mother and her fetus, usually involving Rh factor. An Rh-negative mother produces antibody to an Rh-positive fetus that, in later pregnancies, will destroy the red cells of an Rh-positive fetus. The problem is usually avoided by treating the mother with antibodies to remove the Rh antigen; erythroblastosis fetalis

A condition involving the deposition of an iron-containing pigment (hemosiderin) mainly in the liver and the spleen. The pigment comes from hemoglobin released from disintegrated red blood cells

A clotting disorder caused by destruction of platelets that usually follows a viral illness. Causes petechiae and hemorrhages into the skin and mucous membranes

An acute infectious disease caused by Epstein–Barr virus (EBV). Characterized by fever, weakness, lymphadenopathy, hepatosplenomegaly, and atypical lymphocytes (resembling monocytes)

A condition in which overactive bone marrow produces too many red blood cells. These interfere with circulation and promote thrombosis and hemorrhage. Treated by blood removal. Also called erythremia, Vasquez–Osler disease

Presence of microorganisms in the blood

Hereditary anemia in which red blood cells are round instead of disk-shaped and rupture (hemolyze) excessively

An often fatal disorder in which multiple clots form in blood vessels

A hereditary bleeding disease caused by lack of von Willebrand factor, a substance necessary for blood clotting

A protein that appears in the urine of patients with multiple myeloma

A test for detection of antibodies to red blood cells such as appear in cases of autoimmune hemolytic anemias

Separation of particles in a liquid by application of an electrical field; used to separate components of blood.

Enzyme-linked immunosorbent assay. A highly sensitive immunologic test used to diagnose HIV infection, hepatitis, and Lyme disease, among others

A pure antibody produced in the laboratory; used for diagnosis and treatment

A scale that measures the relative acidity or alkalinity of a solution. Represents the amount of hydrogen ion in the solution

Test used to determine absorption of vitamin B12 by measuring excretion of radioactive B12 in the urine. Used to distinguish pernicious from nutritional anemia

The appearance of antibodies in the serum in response to a disease or an immunization

A very sensitive test used to detect small amounts of antibodies in the blood

A commonly used blood stain

An agent that prevents or delays blood coagulation

A drug that counteracts the effects of histamine and is used to treat allergic reactions

A procedure in which blood is withdrawn, a portion is separated and retained, and the remainder is returned to the donor. Apheresis may be used as a suffix with a root meaning the fraction retained, such as plasmapheresis, leukapheresis

A person's own blood. May be donated in advance of surgery and transfused if needed

A sediment obtained by cooling. The fraction obtained by freezing blood plasma contains clotting factors

Treatment of allergy by small injections of the offending allergen. This causes an increase of antibody to destroy the antigen rapidly on contact

Blood from animals of the same species, such as human blood used for transfusion from one person to another. Blood used for transfusions must be compatible with the blood of the recipient

Depression of the immune response. May be correlated with disease but also may be induced therapeutically to prevent rejection in cases of tissue transplantation

An anti-HIV drug that acts by inhibiting an enzyme the virus needs to multiply

A gland on the superior surface of the kidney. The outer region (cortex) secretes steroid hormones; the inner region (medulla) secretes epinephrine (adrenaline) (root: adren/o)

Pertaining to a ductless gland that secretes directly into the blood

A secretion of an endocrine gland. A substance that travels in the blood and has a regulatory effect on tissues, organs, or glands

The pituitary gland (root: hypophys); named from hypo, meaning “below,” and physis, meaning “growing,” because the gland grows below the hypothalamus

A portion of the brain that controls the pituitary gland and is active in maintaining homeostasis

Clusters of endocrine cells in the pancreas that secrete hormones to regulate sugar metabolism; also called islets of Langerhans or islet cells (root insul/o means “island”)

Small endocrine glands on the posterior thyroid that act to increase blood calcium levels; there are usually four to six parathyroid glands (root: parathyr/o, parathyroid/o); the name literally means “near the thyroid”

A small gland in the brain. Appears to regulate mood, daily rhythms, and sexual development in response to environmental light. Secretes the hormone melatonin

A small endocrine gland at the base of the brain. The anterior lobe secretes growth hormone and hormones that stimulate other glands; the posterior lobe releases ADH and oxytocin manufactured in the hypothalamus

A group of hormones produced throughout the body that have a variety of effects, including stimulation of uterine contractions and regulation of blood pressure, blood clotting, and inflammation

A site on the cell membrane or within the cell to which a substance, such as a hormone, attaches

A hormone made from lipids and including the sex hormones and the hormones of the adrenal cortex

The specific tissue on which a hormone acts; may also be called the target organ

An endocrine gland on either side of the larynx and upper trachea. It secretes hormones that affect metabolism and growth and a hormone (calcitonin) that regulates calcium balance (root: thyr/o, thyroid/o).

Overgrowth of bone and soft tissue, especially in the hands, feet, and face, caused by an excess of growth hormone in an adult. The name comes from acro meaning “extremity” and megal/o meaning “enlargement”

A disease resulting from deficiency of adrenocortical hormones. It is marked by darkening of the skin, weakness, and alterations in salt and water balance

A neoplasm of a gland

A condition caused by hypothyroidism in an adult. There is dry, waxy swelling, most notable in the face; formerly called myxedema

Overactivity of the adrenal cortex resulting from excess production of ACTH by the pituitary

A condition resulting from an excess of hormones from the adrenal cortex. It is associated with obesity, weakness, hyperglycemia, hypertension, and hirsutism (excess hair growth)

A disorder caused by insufficient release of ADH from the posterior pituitary. It results in excessive thirst and production of large amounts of very dilute urine. The word insipidus means “tasteless,” referring to the dilution of the urine

A disorder of glucose metabolism caused by deficiency of insulin production or failure of the tissues to respond to insulin. Type 1 results from autoimmune destruction of pancreatic islet cells; it generally appears in children and requires insulin administration. Type 2 generally occurs in obese adults; it is treated with diet, exercise, drugs to improve insulin production or activity, and sometimes insulin. The word mellitus comes from the Latin root for honey, referring to the sugar content of the urine

Protrusion of the eyeballs, as seen in Graves disease

Overgrowth caused by an excess of growth hormone from the pituitary during childhood; also called giantism

A test that measures the binding of glucose to hemoglobin during the lifespan of a red blood cell. It reflects the average blood glucose level over two to three months and is useful in evaluating long-term therapy for diabetes mellitus. Also called A1c test

Excess sugar in the urine

Enlargement of the thyroid gland. May be toxic or nontoxic. Simple (nontoxic) goiter is caused by iodine deficiency

An autoimmune disease resulting in hyperthyroidism. A prominent symptom is exophthalmos (protrusion of the eyeballs). Also called diffuse toxic goiter

Excess glucose in the blood

Abnormally low level of glucose in the blood

A condition resulting from an overdose of insulin, causing hypoglycemia

A condition caused by congenital lack of thyroid secretion and marked by arrested physical and mental development; also called congenital hypothyroidism

Acidosis (increased acidity of body fluids) caused by an excess of ketone bodies, as in diabetes mellitus; diabetic acidosis

A state of hyperglycemia caused by cellular resistance to insulin, as seen in type 2 diabetes, in association with other metabolic disorders; syndrome X or insulin resistance syndrome

Underactivity of the entire pituitary gland

Irritability and spasms of muscles; may be caused by low blood calcium and other factors

A saddle-shaped depression in the sphenoid bone that contains the pituitary gland (literally means “Turkish saddle”)

A bone at the base of the skull that houses the pituitary gland

Condition caused by overproduction of androgens from the adrenal cortex, resulting in masculinization; may be congenital or acquired, usually as a result of an adrenal tumor

Hyperaldosteronism caused by an adrenal tumor

A tumor of the pituitary gland

A chronic thyroiditis of autoimmune origin

High blood glucose levels after glucose intake that may signal borderline diabetes mellitus

Accumulation of ketone bodies, such as acetone, in the body. Usually results from deficiency or faulty metabolism of carbohydrates, as in cases of diabetes mellitus and starvation

A hereditary disorder that causes tumors in several endocrine glands; classified according to the combination of glands involved

A usually benign tumor of the adrenal medulla or other structures containing chromaffin cells (cells that stain with chromium salts); phe/o means “brown” or “dusky.” The adrenal tumor causes increased production of epinephrine.

Sudden massive hemorrhage and degeneration of the pituitary gland associated with a pituitary tumor. Common symptoms include severe headache, visual problems, and loss of consciousness

A mood disorder with lethargy, depression, excessive need for sleep, and overeating that generally occurs in winter. Thought to be related to melatonin levels as influenced by environmental light

Hypofunction of the anterior pituitary (panhypopituitarism), usually because of an infarction; pituitary cachexia (ka-KEK-sē-a)

A sudden onset of the symptoms of thyrotoxicosis occurring in patients with hyperthyroidism who are untreated or poorly treated. May be brought on by illness or trauma. Also called thyroid crisis

Condition resulting from overactivity of the thyroid gland. Symptoms include anxiety, irritability, weight loss, and sweating. The main example of thyrotoxicosis is Graves disease

Degeneration of bone caused by excess production of parathyroid hormone. Also called Recklinghausen disease of bone

Measurement of glucose in the blood after a fast of at least eight hours. A reading greater than or equal to126 mg/dL indicates diabetes. Also called fasting blood glucose (FBG) or fasting blood sugar (FBS)

Calculation based on the amount of T4 present and T3 uptake, used to diagnose thyroid dysfunction

Measurement of glucose levels in blood plasma after administration of a challenge dose of glucose to a fasting patient. Used to measure patient's ability to metabolize glucose. A value greater than or equal to 200 mg/dL in the two-hour sample indicates diabetes

A test that measures thyroid uptake of radioactive iodine as an evaluation of thyroid function

A method of measuring very small amounts of a substance, especially hormones, in blood plasma using radioactively labeled hormones and specific antibodies

Visualization of the thyroid gland after administration of radioactive iodine

binding globulin (TBG) test - Test that measures the main protein that binds T4 in the blood

Removal of a pituitary tumor through the sphenoid sinus (space in the sphenoid bone)