Medical terms - Letter B | MedicalVocabulary.org

B cell

A type of white blood cell and, specifically, a type of lymphocyte. Many B cells mature into what are called plasma cells that produce antibodies (proteins) necessary to fight off infections while other B cells mature…
B variant GM2-gangliosidosis

See: Tay-Sachs disease
B virus

An infectious agent commonly found among macaque monkeys, including rhesus macaques, pig-tailed macaques, and cynomolgus monkeys. Monkeys infected with this virus usually have no or mild symptoms. In humans, however, B…
B(a)P

Benzo(a)pyrene
B-type natriuretic peptide

A 32-amino-acid polypeptide secreted by the ventricles of the heart in response to excessive stretching of myocytes (heart muscles cells) in the ventricles. The levels of B-type natriuretic peptide (BNP) are elevated in…
B. burgdorferi

Short for Borrelia burgdorferi, the cause of Lyme disease. Once the full name of a bacterium has been given, it is customary to refer to it in its short form. For example, 'Borrelia burgdorferi...is responsible for Lyme…
B. cepacia

See: Burkholderia cepacia
B. coli

The protozoan parasite Balantidium coli. See: Balantidium
B. quintana

Also called Rochalimaea quintana), Bartonella quintana is an unusual rickettsial organism that can multiply within the gut of the body louse and then can be transmitted to humans. Transmission to people can occur by…
B.i.d. (on prescription)

Seen on a prescription, b.i.d. means twice (two times) a day. It is an abbreviation for 'bis in die' which in Latin means twice a day. The abbreviation b.i.d. is sometimes written without a period either in lower-case…
Ba

The symbol for barium
Babesiosis

An illness caused by the parasite Babesia which is transmitted from animals to humans by ticks. In the US, it is typically contracted in the Northeast or Midwest -- in southern New England or New York State and in…
Babinski reflex

An important neurologic test based, believe it or not, upon what the big toe does when the sole of the foot is stimulated. If the big toe goes up, that may mean trouble. The Babinski reflex is obtained by stimulating…
Babinski response

An important neurologic examination based upon what the big toe does when the sole of the foot is stroked. If the big toe goes up, that may mean trouble. The Babinski response is obtained by stimulating the external…
Babinski sign

An important neurologic examination based upon what the big toe does when the sole of the foot is stimulated. If the big toe goes up, that may mean trouble. The Babinski sign is obtained by stimulating the external…
Baby blues

A common temporary psychological state right after childbirth when a new mother may have sudden mood swings, feeling very happy, then very sad, cry for no apparent reason, feel impatient, unusually irritable, restless…
Baby teeth

See: Primary teeth
Baby walker

A device that allows a baby to move about in a half-seated, half-upright position. A 'walker' may paradoxically delay a baby in development. The baby using a walker tends to be slow in reaching motor milestones such as…
Baby, fetal alcohol syndrome

See: Fetal alcohol syndrome
Babysitter's elbow

See: Nursemaid's elbow
BAC

Abbreviation for bacterial artificial chromosome. An artificially created chromosome in which medium-sized segments of foreign DNA (pieces of DNA 100,000 to 300,000 bases in length from another species) are cloned into…
Bacillary angiomatosis

A bacterial infection due to a cat scratch most often seen today in people with HIV. The disease characteristically presents with swollen lymph nodes (lymphadenitis), sore throat, fatigue, and fever, chills, sweats…
Bacille Calmette Guerin

An effective immunization against tuberculosis. Commonly abbreviated BCG, it is an attenuated (weakened) version of a bacterium called Mycobacterium bovis which is closely related to Mycobacterium tuberculosis, the…
Bacillophobia

An abnormal and persistent fear of bacilli (bacteria). A phobia is an unreasonable sort of fear that can cause avoidance and panic. Phobias are a relatively common type of anxiety disorder. Phobias can be treated with…
Bacillus

A large family of bacteria that have a rod-like shape. They include the bacteria that cause food to spoil, and also those responsible for some types of diseases. Helpful members of the bacillus family are used to make…
Bacillus anthracis

The bacterium that causes anthrax. Anthrax differs from most bacteria in that they exist in an inactive (dormant) state called spores. The spores are found in soil, animal carcasses and feces (including sheep, goats…
Back pain

Pain felt in the low or upper back. There are many causes of back pain. Pain in the low back can relate to the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and…
Back pain, low

Back pain, low: Pain in the lower back area that can relate to problems with the lumbar spine, the discs between the vertebrae, the ligaments around the spine and discs, the spinal cord and nerves, muscles of the low…
Backbone

The spine. A flexible row of bones stretching from the base of the skull to the tailbone
Background radiation

Radiation that comes from environmental sources including the earth's crust, the atmosphere, cosmic rays, and radioisotopes. Natural sources of radiation account for the largest amount of radiation exposure received by…
Bacteremia

The presence of live bacteria in the bloodstream. Bacteremia is analogous to viremia (the presence of a virus in the blood) and parasitemia (the presence of a parasite in the blood). Bacteremia, viremia and parasitemia…
Bacteria

Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Examples of bacteria include: > >Acidophilus, a normal inhabitant of…
Bacterial

Of or pertaining to bacteria. For example, a bacterial lung infection
Bacterial artificial chromosome

Inflammation of the prostate gland of sudden (acute) onset due to bacterial infection. The symptoms include chills, fever, pain in the lower back and genital area, body aches, burning or painful urination, and the…
Bacterial prostatitis, acute

Prostatitis, acute: Inflammation of the prostate gland of sudden (acute) onset due to bacterial infection. The symptoms include chills, fever, pain in the lower back and genital area, body aches, burning or painful…
Bacterial prostatitis, chronic

Prostatitis, chronic: Longstanding bacterial infection of the prostate gland superimposed on a defect in the prostate. (The prostate is a small organ below the bladder which surrounds the urethra, the tube that carries…
Bacterial vaginosis

Bacterial vaginosis: A vaginal condition characterized by an abnormal vaginal discharge due to an overgrowth of normal bacteria in the vagina. Women with bacterial vaginosis have less of the normal vaginal bacteria…
Bacteriaphobia

An abnormal and persistent fear of germs. Sufferers from bacteriaphobia experience undue anxiety even though they realize that most germs are not pathogens (disease-causing germs). To avoid germs, they may repeat…
Bacteriocidal

The science and study of bacteria and their relation to medicine and to other areas such as agriculture (e.g., farm animals) and industry. Bacteria are single-celled microorganisms which can live as independent…
Bacteriology

The science and study of bacteria and their relation to medicine and to other areas such as agriculture (e.g., farm animals) and industry. Bacteria are single-celled microorganisms which can live as independent…
Bacteriophage

See: Phage
Bacteriostatic

Capable of inhibiting the growth or reproduction of bacteria. Different from bactericidal (capable of killing bacteria outright)
Bacterium

The singular of bacteria
Bad air

Any air considered noxious. Today, air filled with tobacco smoke might be considered 'bad air.' So might air contaminated by the emissions of power plants. In the past, bad air was termed a miasma, a poisonous vapor or…
BAEP (brainstem auditory evoked potentials)

See: ABR test
Bag of waters

Popular name for the amniotic sac together with the amniotic fluid within it. The amniotic sac is formed by the amnion within the uterus and encloses the fetus. This sac bursts normally during the birthing process…
Bag, air

A bag that fills with air, designed for frontal impact crashes, the kind of crashes which account for more than half of all passenger vehicle occupant deaths. Air bags are designed to limit head and chest injuries. But…
Baker cyst

Baker cyst: A swelling in the space behind the knee (the popliteal space) composed of a membrane-lined sac filled with synovial fluid that has escaped from the joint. Baker cyst is named after the British surgeon…
Baker's yeast

Saccharomyces cerevisiae
Balance

A biological system that enables us to know where our bodies are in the environment and to maintain a desired position. Normal balance depends on information from the inner ear, other senses (such as sight and touch)…