Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «S»:
Selenium: An essential trace mineral that functions largely in the form of proteins, called selenoproteins, which act as enzymes and help prevent damage to cells in the body by oxidants in the environment or those produced by normal metabolism.
The recommended dietary allowance (RDA) is currently ...
Selenium deficiency: See Deficiency, selenium....
Selenium excess: See Excess selenium....
Selenium poisoning: Poisoning from selenium, a naturally occurring substance that is toxic at high concentrations but is also a nutritionally essential element. Hydrogen selenide is the most acutely toxic selenium compound. Acute (short-term) exposure to elemental selenium, hydrogen selenide, and ...
Selenocysteine: An amino acid in which selenium takes the place of sulfur in the amino acid cysteine. Its formula is H-Se-CH2-CH(NH2)-COOH. Selenocysteine is an essential component of selenium-containing proteins, or selenoproteins....
Selenoprotein: A peculiar class of proteins that contain the essential trace element selenium. The selenium in these proteins is in the amino acid selenocysteine....
Selenosis: Selenium poisoning. Selenium posioning may be acute (short-term) or chronic (long-term). The effects of acute selenium poisoning depend upon the route of exposure.
Acute inhalation exposure to selenium (usually in the form of selenium dioxide or hydrogen selenide) primarily results in r...
Self, fear of
Self, fear of: An irrational fear of oneself, an intense self-fear that is groundless. Fear of oneself is termed "autophobia" which comes from two Greek words: "autos" (self) and "phobos" (fear) = literally, self-fear, fear of oneself. "Autos" has given us many English words such as "automatic" and ...
Self-harm: see: non-suicidal self injury....
Selfish operon: A hypothesis according to which the clustering of genes and their subsequent organization into operons is beneficial to the constituent genes because it enables the transfer of functionally coupled genes, genes involved in the same biosynthetic pathway.
The selfish operon hypothesis ...
Sella turcica: The "Turkish saddle" in which sits the pituitary gland.
The sella is a bony box in the middle of the head. It was called the sella turcica (the Turkish saddle) because of its resemblance to a saddle used by the Turks (and Arabs) which had supports in front and back. (By comparison, th...
SEM: Scanning electron microscope....
Semen: The fluid that is released through the penis during orgasm. Semen is made up of fluid and of sperm. The fluid comes from the prostate, seminal vesicle and other sex glands. The sperm are manufactured in the testicles. The seminal fluid helps transport the sperm during orgasm. Seminal fluid c...
Semen DNA analysis
Semen DNA analysis: The detection and investigation in a sample of semen. Let us assume that a man's semen is alleged to be on a piece of
fabric. To learn whether the cloth is stained by the suspect's semen, DNA testing can be done.
Here is how it works:
First, it must be shown that the stain cont...
SEMG: Surface EMG....