(pŏt-bĕl-ē) Slang term for the selective deposition of adipose tissue in the abdominal subcutaneous tissue. It is seen, e.g., in patients with the metabolic syndrome (syndrome X).
(pō′tĕn-sē) [L. potentia, power] 1. Strength; force; power. 2. Strength of a medicine. 3. The ability of a man to perform coitus. 4. For a cell, the range of specialized cell types into which it can differentiate. The major cell types are: totipotent cells, which can form any cell in an organism; pluripotent cells, which can form most cell types in an organism; multipotent cells, which can form many cells types in an organism; and unipotent (or monopotent) cells, which can differentiate into only one specialized cell type.
(pō′tĕnt) [L. potens, powerful] 1. Powerful. 2. Highly effective medicinally. 3. Having the power of procreation.
(pŏ-ten′chăl) [L. potentialis, powerful] 1. Existing in possibility; latent. 2. In electricity, voltage or electrical pressure. It is a condition in which a state of tension or pressure, capable of doing work, exists. When two electrically charged bodies of different potentials are brought together, an electric current passes from the body of high potential to that of low.
action p. ABBR: AP. A local reversal of the charge across an excitable cell membrane that is propagated along the length of the membrane. In humans, most of the cells that conduct action potentials are neurons or muscles. Neurons and muscle cells actively maintain an excess of negative ions inside the cell, which gives them a cross-membrane charge of about −75 to −80 mV. If ion channels in one area of the membrane are caused to open briefly, then charged ions move across the membrane, reducing the charge differential. When the cross-membrane charge reaches a threshold level (often about −40 to −60 mV), sodium ion channels (voltage-sensitive or voltage-gated channels) open in the vicinity. Sodium ions rush into the cell, and the cross-membrane potential temporarily rises to a peak of about +40 to +50 mV, the height of the action potential in that region. This flood of ions also depolarizes adjacent membrane regions, which quickly reach their threshold levels, opening their voltagegated channels. In this way, the depolarization spreads along the membrane.
after p. The small ionic changes across an excitable membrane that follow an action potential.
demarcation p. The difference in electrical potential between an intact longitudinal surface and the injured end of a muscle or nerve. SYN: injury p.
evoked p. The electroencephalographic record of electrical activity produced at one of several levels in the central nervous system (CNS) by stimulation of an area of the sensory nerve system. Evoked potentials differ from the spontaneous electrical activity in the nervous system in that they ...