Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «B»:
Blighted ovum: A fertilized ovum (egg) that did not develop or whose development ceased at an early stage, before 6 or 7 weeks of gestation. On the ultrasound examination of a blighted ovum, only the gestational sac that normally surrounds the embryo can be seen. There is usually no embryo inside th...
Blind: 1. Unable to see. Without part or all of the sense of sight.
2. In a clinical trial, not to know the treatment given or received. The participant is not told whether they are in the experimental or control arm of the study. Also called masked....
Blind spot: In ophthalmology, a blind spot is:
A small area of the retina where the optic nerve
enters the eye; this type of blind spot occurs normally in all eyes.
Any gap in the visual field corresponding to an area of the retina where no visual cells are present; this type of blind spot ...
Blinded study: A study done in such a way that
the patients or subjects do not know (is blinded as to) what treatment they are receiving to ensure that the results are not affected by a placebo effect (the power of suggestion)....
Blindness: Loss of useful sight.
Blindness can be temporary or permanent. Damage to any portion of the eye, the optic nerve, or the area of the brain responsible for vision can lead to blindness. There are numerous (actually, innumerable) causes of blindness. The current politically correct terms ...
Blindness, legal: See: Legal blindness....
Blindness, night: Impaired vision in
dim light and in the dark, due to impaired function of
specific vision cells (namely, the rods) in the retina.
The ability of our eyes to quickly view objects as
they shift from light to dark areas and the ability to see in dim light or at night is an import...
Blister: A collection of fluid underneath the top layer of
skin (epidermis). One that is more than 5 mm in diameter with thin
walls and is full of watery fluid is called a bulla or a bleb. There are many causes of blisters including burns, vesicant agents, friction
forces, and diseases of the ski...
Blister agent: See: Vesicant....
Blister beetle: A blister beetle is one of a number of beetles that have historically been used in dried or powdered form for medicinal purposes to raise blisters on the skin. An example of a blister beetle is the so-called Spanish fly. All blister beetles are soft-bodied beetles and belong to the ...
Blister, blood: a blister full of blood due to a pinch, bruise or repeated friction.
A blister is medically termed a vesicle. One that is more than 5 mm in diameter with thin walls and is full of watery fluid is called a bulla or a bleb.
The word "blister" entered English in the 14th century. It cam...
Blister, fever: A small sore situated on the face or in the
mouth that causes pain, burning, or itching before bursting and
crusting over. The favorite locations are on the lips, chin or cheeks
and in the nostrils. Less frequented sites are the gums or roof of
the mouth (the palate).
Blister, water: See: Water blister....
Blistering agent: See: Vesicant....
Block, caudal: See Caudal anesthesia....